JPH0621491A - Photovoltaic element, manufacture thereof and power generator system using the same - Google Patents

Abstract

PURPOSE:To provide a photovoltaic element which prevents recombination of photovoltaic carriers and improves open voltage and carrier range holes, a method for manufacturing the same and a power generator system using the same. CONSTITUTION:A photovoltaic element has a p-type layer 104, a photoconductive layer (a layer formed of a plurality of i-type layers) and an n-type layer 102 which are formed in multilayer. The photoconductive layer has a multilayer structure having an i-type layer 103 deposited by a muWPCVD method on the side of the p-type layer, and an i-type layer 109 deposited by an RFPCVD method on the side of the n-type layer. The i-type layer 103 contains Si atoms and Ge atoms in such a manner that the position where the band gas is a minimum is in the i-type layer deviated toward the p-type layer from the center of the i-type layer. The i-type layer 109 contains Si atoms and a thickness of 30nm or less in such a manner that the least one of the p-type and n-type layers has a multilayer structure of a layer containing group III or V element as a main constituent element and a layer containing a valence control agent and Si atoms as main constituent element.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pin type photovoltaic element made of a silicon-based non-single-crystal semiconductor material, a method of manufacturing the same, and a power generation system using the same. In particular, the present invention relates to a pin-type photovoltaic element in which the bandgap in the i-type layer is changed, and further relates to a deposition method of the photovoltaic element by microwave plasma CVD. In addition, it relates to a power generation system using the photovoltaic element.

[0002]

2. Description of the Related Art Conventionally, in a photovoltaic device having a pin structure made of a silicon-based non-single-crystal semiconductor material, the i-layer contains silicon atoms and germanium atoms, and the band gap in the i-type layer is changed. Various proposals have been made for electromotive force elements as described below. For example,
(1) "Optimum position co
conditions for a- (Si, Ge): H
using a triode-configurat
ed rf glow discharge system
em ", JA Bragagno, P. Litt.
lefield, A .; Mastrovit and
G. Storeti, Conf. Rec. 19th IE
EE Photovoltaic specialty
s Conference-1987, pp. 878,
(2) "Efficiency improvmen
t in amorphous-SiGe: H sol
ar cells and it's apply
ion to tandem type solar
cells ", S. Yoshida, S. Yamana
ka, M .; Konagai and K.K. Takaha
shi, Conf. Rec. 19th IEEE Ph
autovoltaic Specialists Con
ference-1987, pp. 1101, (3) "
Stability and terrestrial
application of a-Si tand
em type solar cells ", A. Hi
roe, H .; Yamagishi, H .; Nishio,
M. Kondo, and Y. Tawada, Con
f. Rec. 19th IEE PHOTOVOLTA
ic Specialists Conference,
1987, pp. 1111, (4) "Preparat
ion of high quality a-SiG
e: H films and it's applica
toion to the high efficiency
cy triple-junction amorph
ous solar cells, “K. Sato,
K. Kawabata, S .; Terazono, H .; S
asaki, M .; Deguchi, T .; Itagak
i, H. Morikawa, M .; Aiga and
K. Fujikawa, Conf. Rec. 20th
IEEE Photovoltaic Specilis
ts Conference, 1988 pp. 73,
(5) USP 4,816,082, (6) USP 4,4
71,155, (7) USP 4,782,376, etc. have been reported.

A theoretical study of the characteristics of a photovoltaic element with a changed bandgap has been carried out, for example, in (8) "A.
novel design for amorpho
us Silicon alloy solar ce
lls ", S. Guha, J. Yang, A. Pawl.
ikiewicz, T .; Glaftelter, R.M. R
oss, and S.S. R. 0vshinsky, Con
f. Rec. 20th IEEE Photovolt
aic Specialists Conference
-1988 pp. 79, (9) "Numerical
mode1ing of multijunctio
n, amorphous silicon based
P-I-N solar cells ", A.H.P.
awlikiewicz and S.A. Guha, Co
nf. Rec. 20th IEEE Photovol
taic Specialists Conference
e-1988 pp. 251, etc. have been reported.

In such a conventional photovoltaic element, p
/ I, n / i Insert a layer with a changed bandgap at the interface for the purpose of preventing recombination of photoexcited carriers near the interface, increasing the open-circuit voltage, and improving the carrier range of holes. is doing.

[0005]

A conventional photovoltaic element containing silicon atoms and germanium atoms and having a changed band gap is required to have higher performance and reliability in practical use, and recombination of photoexcited carriers is required. It is desired to further improve the suppression of charge generation, the open circuit voltage and the carrier range of holes.

Further, the conventional photovoltaic element has a problem that the conversion efficiency is lowered when the irradiation light applied to the photovoltaic element is weak.

Further, the conventional photovoltaic element has a problem that the photoelectric conversion efficiency is lowered when it is annealed in the presence of vibration in the i layer because of distortion.

An object of the present invention is to provide a photovoltaic element that solves the above-mentioned conventional problems. That is, the present invention is
It is an object of the present invention to provide a photovoltaic device in which recombination of photoexcited carriers is prevented and an open circuit voltage and a carrier range of holes are improved.

It is another object of the present invention to provide a photovoltaic device having improved conversion efficiency when the irradiation light applied to the photovoltaic device is low.

A further object of the present invention is to provide a photovoltaic device in which the photoelectric conversion efficiency is less likely to decrease when annealed under vibration for a long period of time.

Furthermore, the present invention has an object to provide a photovoltaic element in which the photoelectric conversion efficiency is less likely to change with a change in temperature.

A further object of the present invention is to provide a method of manufacturing a photovoltaic device which achieves the above object.

Still another object of the present invention is to provide a system using a photovoltaic element that achieves the above object.

[0014]

DISCLOSURE OF THE INVENTION The present invention has solved the problems of the prior art and, as a result of extensive studies to achieve the object of the present invention, the photovoltaic element of the present invention was found to be a silicon-based non-single-crystal semiconductor material. In a photovoltaic element configured by laminating at least a p-type layer, a photoconductive layer (a layer including a plurality of i-type layers) and an n-type layer, the photoconductive layer is on the p-type layer side. I deposited by microwave plasma CVD method located at
A laminated structure including at least a mold layer and an i-type layer located on the n-type layer side and deposited by an RF plasma CVD method, wherein the i-type layer deposited by the microwave plasma CVD method is at least silicon. An i-type layer containing an atom and a germanium atom, and the position of the minimum value of the band gap is deviated from the center of the i-type layer toward the p-type layer, and the i-type layer is deposited by the RF plasma CVD method.
The mold layer contains at least silicon atoms and has a layer thickness of 30 nm.
And a layer in which at least one of the p-type layer and the n-type layer is a main constituent element of a Group III element or a Group V element of the periodic table, and a valence electron control agent is contained, and a silicon atom is a main constituent element. And a layered structure of

Further, as a desirable mode of the photovoltaic element of the present invention, a valence electron control agent serving as a donor and a valence electron control agent serving as an acceptor are contained in the i-type layer deposited by the microwave plasma CVD method. It is characterized by being doped at the same time. These valence electron control agents are listed in Periodic Table II.
The element is a group I element or a group V element, and is characterized by being distributed in the i-type layer formed by the microwave plasma CVD method.

As a desirable mode of the photovoltaic element of the present invention, in the i-type layer deposited by the microwave plasma CVD method, the maximum band gap is at least in the p-type layer direction or the n-type layer direction. And a band gap maximum value region is 1 or more and 30 nm or less.

Further, the i-type layer formed by the microwave plasma CVD method and / or the i-type layer formed by the RF plasma CVD method contains oxygen atoms and / or nitrogen atoms.

Further, it is characterized in that the hydrogen content contained in the i-type layer formed by the microwave plasma CVD method changes corresponding to the content of silicon atoms.

In particular, the group III element of the periodic table or /
Also, it is desirable that the layer containing a Group V element as a main constituent element has a thickness of 1 nm or less.

The photovoltaic element manufacturing method of the present invention comprises stacking at least a p-type layer made of a silicon-based non-single-crystal semiconductor material, a photoconductive layer (a layer made of a plurality of i-type layers), and an n-type layer. In the method for manufacturing a photovoltaic device, the i-type layer on the p-type layer side of the photoconductive layer is exposed to a source gas containing at least a silicon atom-containing gas and a germanium atom-containing gas at a pressure of 50 mTorr or less. Then, change the source gas to 1
The microwave plasma CVD method in which the microwave energy lower than the microwave energy required to decompose it by 00% and the RF energy higher than the microwave energy are simultaneously acted on, the position of the minimum value of the band gap is at the center of the i-type layer. Of the i-type layer on the side of the n-type layer of the photoconductive layer by RF plasma CVD using a source gas containing at least a silicon atom-containing gas by 2 nm. 30 nm or less at a deposition rate of 1 / sec or less, and at least one of the p-type layer and the n-type layer is a Group III element or V group in the periodic table.
It is characterized in that it is formed in a laminated structure of a layer containing a group element as a main constituent element and a layer containing a valence electron control agent and containing silicon atoms as a main constituent element. Further, i on the p-type layer side of the photoconductive layer
At the time of forming the mold layer, it is preferable to simultaneously dope the valence electron control agent serving as a donor and the valence electron control agent serving as an acceptor.

A desirable mode of the method for manufacturing a photovoltaic element of the present invention is to deposit a mixture of a silicon atom-containing gas and a germanium-containing gas at a distance of 5 m or less from a deposition chamber in the microwave plasma CVD method. Is characterized by.

A power generation system utilizing the photovoltaic element of the present invention is for storing the photovoltaic element of the present invention and the electric power supplied from the photovoltaic element and / or supplying the electric power to an external load. At least a storage battery and a control system for monitoring the voltage and / or current of the photovoltaic element to control the power supplied from the photovoltaic element to the storage battery and / or the external load. Characterize.

[0023]

The operation will be described in detail below with reference to the drawings.

FIG. 1 is a schematic explanatory view showing an example of the photovoltaic element of the present invention. The photovoltaic device of the present invention includes a conductive substrate 101 having a light reflection layer and a light reflection increasing layer, an n-type silicon-based non-single-crystal semiconductor layer 102, and RF plasma CVD.
A substantially i-type non-single-crystal semiconductor layer 103 by a microwave plasma method containing at least silicon atoms and germanium atoms, an i-type layer 108 by an RF plasma CVD method, and a valence electron control agent. P-type silicon-based non-single-crystal semiconductor layer 10 containing a layer containing a main constituent element and a valence electron control agent and containing silicon atoms as a main constituent element
4, a transparent electrode 105, a collector electrode 106 and the like.

In the i-type layer formed by the microwave plasma CVD method, the minimum value of the band gap is offset to the p-type layer side, and the conduction band is formed on the p-type layer side of the i-type layer formed by the microwave plasma CVD method. Due to the large electric field, electrons and holes are efficiently separated, and recombination of electrons and holes near the interface between the p-type layer and the i-type layer formed by the microwave plasma CVD method can be reduced. Further, since the electric field in the valence band increases from the i-type layer to the n-type layer by the microwave plasma CVD method, recombination of electrons and holes photoexcited in the vicinity of the n-type layer can be reduced. it can.

Further, the carrier range of electrons and holes can be lengthened by simultaneously adding a valence electron control agent as a donor and a valence electron control agent as an acceptor into the i-type layer formed by the microwave plasma CVD method. it can. In particular, the carrier range of electrons and holes can be effectively lengthened by containing a relatively large amount of the valence electron control agent at the minimum band gap. As a result, the high electric field in the vicinity of the interface between the p-type layer and the i-type layer formed by the microwave plasma CVD method and the high electric field in the vicinity of the n-type layer can be used more effectively. The collection efficiency of electrons and holes photoexcited therein can be markedly improved.

Further, in the vicinity of the interface between the p-type layer and the i-type layer formed by the microwave plasma CVD method, and in the vicinity of the interface between the n-type layer and the i-type layer formed by the microwave plasma CVD method, defect levels (so-called D ⁻ , Since D ⁺ ) is compensated by the valence electron control agent, the dark current (during reverse bias) due to hopping conduction through the defect level is reduced. Especially in the vicinity of the interface, by containing a valence electron control agent in a larger amount than the inside of the i-type layer formed by the microwave plasma CVD method, internal stress such as strain due to a sudden change in the constituent elements peculiar to the interface Can be reduced, and as a result, the defect level near the interface can be reduced. As a result, the open circuit voltage and fill factor of the photovoltaic element can be improved.

In addition, by simultaneously containing a valence electron control agent serving as a donor and a valence electron control agent serving as an acceptor inside the i-type layer, durability against photodegradation is increased. Although the details of the mechanism are unknown, it is generally believed that the dangling bonds generated by light irradiation become the recombination centers of carriers and deteriorate the characteristics of the photovoltaic device.
And in the case of the present invention, both the valence electron control agent which becomes a donor and the valence electron control agent which becomes an acceptor are contained in the i-type layer by a microwave plasma CVD method, and these are 100
% Not activated. As a result, even if dangling bonds are generated by light irradiation, it is considered that they react with the unactivated valence electron control agent to compensate dangling bonds.

Further, even when the intensity of light applied to the photovoltaic element is low, the probability of trapping photoexcited electrons and holes is reduced because the defect level is compensated by the valence electron control agent. Further, as described above, since the dark current during reverse bias is small, a sufficient electromotive force is generated.
Therefore, it exhibits excellent photoelectric conversion efficiency even when the intensity of light applied to the photovoltaic element is weak.

In addition, the photovoltaic element of the present invention is less likely to lower the photoelectric conversion efficiency even when it is annealed under vibration for a long period of time. Although the detailed mechanism of this is not clear, the decrease in photoelectric conversion efficiency of the conventional photovoltaic device is considered as follows. That is, in order to continuously change the band gap, the constituent elements are also changed to form the photovoltaic element. Therefore, strain is accumulated inside the photovoltaic element, and many weak couplings exist inside the photovoltaic element. It is considered that, as a result of the vibration, weak bonds in the i-type non-single-crystal semiconductor by the microwave plasma CVD method are broken and dangling bonds are formed, so that photoelectric conversion efficiency is lowered. On the other hand, in the case of the present invention, a valence electron control agent serving as a donor and a valence electron control agent serving as an acceptor are simultaneously added, whereby local flexibility is increased, and the photovoltaic element can be annealed by long-term vibration. It is considered that the decrease in the photoelectric conversion efficiency can be suppressed. In addition to this, the number of non-activated donors and acceptors is 3
It is considered that the coordination increases local flexibility.
As a result, it is considered that the photoelectric conversion efficiency is unlikely to decrease even if it is annealed under vibration for a long period of time. However, the amount of unactivated donor or acceptor that forms defects is not more than a certain amount. Therefore, the preferable amount of the non-activated donor or acceptor is 0.1 to 100.
It is ppm.

In addition, a p-type layer and microwave plasma C
Between the i-type layers formed by the VD method, 3 i-type layers formed by the RF plasma CVD method at a deposition rate of 2 nm / sec or less are formed.
By inserting 0 nm or less, the photoelectric conversion efficiency of the photovoltaic element can be further improved. In particular, the photovoltaic element of the present invention is less likely to change the photoelectric conversion efficiency when used in an environment where the temperature changes greatly.

The i-type non-single-crystal semiconductor layer deposited by the RF plasma CVD method has a deposition rate of 2 nm / sec or less, and is deposited with low power in which vapor phase reaction does not easily occur. As a result, the packing density of the deposited film is high, and when the i-type layer is laminated with the i-type layer deposited by the microwave plasma CVD method, the interface state between the i-type layers is reduced. Particularly, when the deposited film is deposited at a rate of 5 nm / sec or more by the microwave plasma method, the microwave plasma C is stopped and then the microwave plasma C
Since the vicinity of the surface of the i-type layer formed by the VD method is not relaxed sufficiently, the surface level is extremely large. It is considered that when a deposited film having a slow deposition rate is formed on the surface of such an i-type layer by the RF plasma method, it can be reduced by annealing due to diffusion of hydrogen atoms which occurs at the same time as the formation of the deposited film.

In addition, an n-type layer and microwave plasma C
By forming the i-type layer of 30 nm or less at a deposition rate of 2 nm / sec or less between the VD i-type layers by the RF plasma CVD method, the photoelectric conversion efficiency of the photovoltaic element can be further improved, and the temperature can be improved. Even when used in an environment where there is a large change, the photoelectric conversion efficiency is less likely to change.

In the deposition by the microwave plasma CVD method, since the kinetic energy of ions is larger than that in the RF plasma CVD method, it is considered that the lower semiconductor layer is damaged. Therefore, it is necessary to use a semiconductor layer having resistance to ion damage as the lower semiconductor layer. Further, the deposited film deposited by the microwave plasma CVD method is a good semiconductor film and the deposition conditions are lower. It is necessary to deposit under conditions that are less likely to damage the. The deposition conditions for the photovoltaic device of the present invention are suitable to achieve this end.

As a result, it is possible to form a photovoltaic device having a small interface state at the interface between the n-type layer and the i-type layer, and to improve the open circuit voltage and short-circuit current of the device.

In the present invention, for example, a p-type layer is used as a periodic table element.
Layers containing Group III elements as main constituent elements (hereinafter referred to as Periodic Table III
A layer containing a group element or a group V element as a main constituent element is referred to as a doping layer A) and a layer containing a valence electron control agent and containing silicon atoms as a main constituent element (hereinafter referred to as a doping layer B). With the laminated structure, the light transmittance of the p-type layer can be increased and the specific resistance of the p-type layer can be reduced. In particular, it is preferable that the side of the p-type layer in contact with the photoconductive layer is a layer containing a valence electron control agent and having silicon as a main constituent element (doping layer B).
By connecting the photoconductive layer and the p-type layer in this manner, it becomes possible to reduce defects between the photoconductive layer and the p-type layer.

The layer thickness of 0.01 to 1 nm is the optimum range for the layer thickness (doping layer A) of which the group III atom of the periodic table is the main constituent element constituting the p-type layer. The content of hydrogen contained in the layer containing a Group III element of the periodic table as a main constituent element is preferably 5% or less.
The content of the valence electron control agent contained in the layer (doping layer B) containing the valence electron control agent constituting the p-type layer and having silicon atoms as the main constituent element is 1500 ppm to 10,000 p
pm is mentioned as a preferable range.

Although the p-type layer has been described above, the above-described effects can be similarly obtained by using the same laminated structure for the n-type layer.

Next, the present invention will be described with reference to band diagrams.

FIG. 2-1 is a schematic explanatory view of an example in which the band gap of the photovoltaic element of the present invention changes. This figure shows the change in the bandgap in the i-type layer based on 1/2 (Eg / 2) of the bandgap. In the figure, the left side is the p-type layer (not shown) side, and the right side is the n-type layer (not shown) side. In the example of FIG. 2A, the minimum value of the band gap is near the p-type layer, and the maximum value of the band gap is in the p-type layer direction and the n-type layer direction. The i-type layer 211 and the i-type layer 212 are layers deposited by a microwave plasma CVD method, and the i-type layer 213 is R
It is a non-single crystal silicon layer deposited by the F plasma CVD method. At the junction between the i-type layer 211 and the i-type layer 213, the hydrogen contents of the i-type layer 211 and the i-type layer 213 are adjusted so that the band gaps are almost equal.

FIG. 2-2 is a schematic explanatory view of changes in bandgap similar to FIG. 2-1. In FIG. 2B, as in FIG. 2A, the minimum value of the bandgap is closer to the p-type layer (not shown), but the maximum value of the bandgap is in contact with the p-type layer. It is composed of. The i-type layer 221 and the i-type layer 222 are layers deposited by a microwave plasma CVD method, and the i-type layer 223 is R
It is a non-single crystal silicon layer deposited by the F plasma CVD method. The band gaps of the i-type layer 221 and the i-type layer 223 are discontinuously connected. The bandgap configuration of FIG. 2-2 makes it possible to raise the open circuit voltage in particular.

FIGS. 3-1 to 3-3 show RF between the n-type layer and the i-type layer formed by the microwave plasma CVD method and between the p-type layer and the i-type layer formed by the microwave plasma CVD method. It is a schematic explanatory view showing a band gap change of a photovoltaic device having an i-type layer by a plasma CVD method. In each figure, the change in bandgap is drawn based on Eg / 2, and an n-type layer (not shown) is on the right side of the band diagram and a p-type layer (not shown) is on the left side.

FIG. 3A shows the i-type layer 312 formed by the RF plasma CVD method in the i-type layer on the p-type layer side, and the band gap by the microwave plasma CVD method is changed from the n-type layer side to the p-type layer side. There is a decreasing i-type layer 311,
An i-type layer 313 formed by RF plasma CVD near the n-type layer
Is an example. And the minimum value of the band gap is i
It is located at the interface between the mold layer 312 and the i-type layer 311. Further, the band joining between the i-type layer 311 and the i-type layer 312 is
They are connected discontinuously. By thus providing the i-type layer by the RF plasma CVD method, it is possible to suppress dark current due to hopping conduction via the defect level of the photovoltaic device during reverse bias as much as possible, and as a result, the photovoltaic device is obtained. The open circuit voltage of is increased.

The i-type layer 3 formed by the RF plasma CVD method
The layer thickness of 13 is a very important factor and the preferred layer thickness range is 1 to 30 nm. When the layer thickness of the i-type layer having a constant band gap is smaller than 1 nm, it is impossible to suppress the dark current due to hopping conduction via the defect level, and it is impossible to expect the open circuit voltage of the photovoltaic element to be improved. On the other hand, when the thickness is thicker than 30 nm, the i-type layer 31
3, the photoexcited holes are likely to be accumulated in the vicinity of the interface of the i-type layer 311 whose bandgap is changed from that of No. 3, and thus the collection efficiency of photoexcited carriers is reduced. That is, the short circuit photocurrent is reduced.

FIG. 3-2 shows RF plasma CVD between the p-type layer and the i-type layer 321 formed by the microwave plasma CVD method.
An i-type layer 322 having a constant band gap by
Further, an i-type layer 323 formed by the RF plasma CVD method having a band gap equal to that of the i-type layer 321 is provided between the n-type layer and the i-type layer formed by the microwave plasma CVD method.

FIG. 3-3 shows between the p-type layer and the i-type layer 331 formed by the microwave plasma CVD method and between the n-type layer and the i-type layer 3.
RF plasma CVD with constant band gap between 31
This is an example in which i-type layers 332 and 333 are provided by the method. When a reverse bias is applied to the photovoltaic element, the dark current is further reduced and the open circuit voltage of the photovoltaic element is increased.

3-4 to 3-7 show RF between the p-type layer and the i-type layer formed by the microwave plasma CVD method and between the n-type layer and the i-type layer formed by the microwave plasma CVD method.
Photovoltaic having an i-type layer having a constant bandgap formed by plasma CVD method and having a region where the bandgap is rapidly changed toward the p-type layer or the n-type layer of the i-type layer formed by microwave plasma CVD method It is an example of an element.

FIG. 3-4 shows the space between the p-type layer and the i-type layer 341 formed by the microwave plasma CVD method, and the n-type layer and the i-type layer 3.
41, i-type layers 342 and 343 having a constant band gap formed by the RF plasma CVD method are provided, and the i-type layer 341 having a changed band gap has the minimum band gap position deviated to the p-type layer side. , I-type layer 341 and i-type layers 342 and 343 are connected continuously. By making the bandgap continuous, electrons and holes photoexcited in the region where the bandgap of the i-type layer changes can be efficiently collected in the n-type layer and the p-type layer, respectively. In particular, when the i-type layers 342 and 343 having a constant band gap are as thin as 5 nm or less, the band gap of the i-type layer 341 is abruptly changed in the dark current when a reverse bias is applied to the photovoltaic element. Can be reduced, and therefore the open circuit voltage of the photovoltaic element can be increased.

In the photoconductive layer shown in FIG. 3-5, the i-type layer 351 having a changed band gap formed by the microwave plasma CVD method is discontinuous with the i-type layers 353 and 352 having a constant band gap formed by the RF plasma CVD method. In this example, the connection is relatively loose. However, i with a constant band gap
I in which the band gap changes with the mold layers 352, 353
Since the type layers 351 are gently connected in the direction in which the bandgap is widened, carriers photo-excited in the i-type layers 351 having a changed bandgap are efficiently injected into the i-type layers 352 and 353 having a constant bandgap. It As a result, the collection efficiency of photoexcited carriers is increased.

Whether the i-type layer having a constant bandgap and the i-type layer having a changed bandgap are connected continuously or discontinuously depends on whether the i-type layer having a constant bandgap and the bandgap rapidly. It depends on the layer thickness of the changing region. When the layer thickness of the region where the i-type layer with a constant band gap is as thin as 5 nm or less and the band gap changes abruptly is 10 nm or less, the i-type layer with a constant band gap and the region where the band gap changes are The photoelectric conversion efficiency of the photovoltaic element is higher when the cells are connected in series. On the other hand, when the layer thickness of the i-type layer having a constant band gap is 5 nm or more and the layer thickness in the region where the band gap changes rapidly is 10 to 30 nm, the band gap changes with the region where the band gap is constant. The conversion efficiency of the photovoltaic element is improved when it is discontinuously connected to the region where the current is applied.

FIGS. 3-6 show an i-type layer 362 having a constant bandgap and an i-type layer 361 having a different bandgap.
In this example, and are connected in two stages. From the position where the band gap is minimum, the band gap is gradually widened and the band gap is rapidly widened.
By connecting to the mold layer 362, it is possible to efficiently collect the photo-excited carriers in the region where the band gap is changed. Further, in FIG. 3-6, the i-type layer 3
The band gap changes sharply toward 63 i
It has a mold layer 361.

FIG. 3-7 shows a mold layer 371 formed by the microwave plasma CVD method, and the i-type layers 373 and 374 formed by the RF plasma CVD method between the i-type layer 371 and the p-type layer and the n-type layer.
Although it is a photovoltaic element having. 3-7 shows microwave plasma CVD between the i-type layer 374 and the i-type layer 371.
The i-type layer 372 having a constant band gap is formed by the method. In this example, the i-type layer 372 and the i-type layer 371 are connected to each other through a two-step change in band gap.

As described above, the i-type layer having a constant band gap and the i-type layer having a changed band gap are connected in a state where the constituent elements are similar to each other, whereby the internal strain can be reduced. As a result, even if it is annealed under vibration for a long period of time, the weak bond in the i-type layer is broken, the defect level is increased, and the photoelectric conversion efficiency is less likely to decrease, so that high photoelectric conversion efficiency is maintained. It is something you can do.

By incorporating a valence electron control agent into the i-type layer, the carrier range in the i-type layer can be increased and the carrier collection efficiency can be increased.
In particular, the collection efficiency of the photoexcited carriers can be further increased by increasing the amount of the valence electron control agent corresponding to the band gap and decreasing the amount in the wide band gap. In addition, the i-type layer with a constant band gap is p
By increasing the amount of the valence electron control agent on the side of the n-type layer and that on the n-type layer side, recombination of photoexcited carriers in the vicinity of the p / i interface and the n / i interface can be prevented. The photoelectric conversion efficiency of the electromotive force element can be improved.

In the present invention, the preferable range of the band gap at the band gap minimum of the i-type layer containing silicon atoms and germanium atoms is variously selected according to the spectrum of irradiation light, but 1.1 ~ 1.
6 eV is desirable.

In the photovoltaic element of the present invention in which the band gap is continuously changed, the slope of the tail state of the valence band is an important factor that influences the characteristics of the photovoltaic element. It is preferable that the slope of the tail state at the minimum value of the band gap to the slope of the tail state at the maximum band gap is smoothly continuous.

Although the photovoltaic element having the pin structure has been described above, it goes without saying that the present invention can also be applied to a photovoltaic element in which a pin structure such as a pinpin structure (double structure) or a pinpinpin structure (triple structure) is laminated. .

FIG. 4-1 is a schematic explanatory view showing an example of a manufacturing apparatus suitable for forming a deposited film of the photovoltaic element of the present invention. The manufacturing apparatus includes a deposition chamber 1001, a dielectric window 1
002, gas introduction pipe 1003, substrate 1004, heater 1005, vacuum gauge 1006, conductance valve 1007, auxiliary valve 1008, leak valve 100
9, waveguide 1010, bias power supply 1011, bias rod 1012, shutter 1013, source gas supply device 1
020, mass flow controllers 1021 to 102
9, gas introduction valves 1031 to 1039, raw material gas cylinder valves 1051 to 1059, pressure regulator 1061
1069, raw material gas cylinders 1071 to 1079 and the like. A method of forming an i-type layer by the microwave plasma method using the manufacturing apparatus of FIG. 4-1 will be described below.

Although the details of the deposition mechanism in the deposition method of the present invention are unknown, it can be considered as follows.

Microwave energy lower than the microwave energy required for 100% decomposition of the raw material gas is applied to the raw material gas, and R higher than the microwave energy is applied.
It is considered that the active species suitable for forming the deposited film can be selected by simultaneously acting the F energy on the source gas. Further, if the internal pressure in the deposition chamber when decomposing the source gas is set to 50 mTorr or less, the mean free path of the active species suitable for forming a high-quality deposited film becomes sufficiently long, so that the gas phase reaction is suppressed as much as possible. Conceivable.

Further, the internal pressure in the deposition chamber is 50 mTorr.
It is considered that in the state of r or less, the RF energy has almost no effect on the decomposition of the source gas and controls the potential between the plasma and the substrate in the deposition chamber. That is, in the case of the microwave plasma CVD method, the potential difference between the plasma and the substrate is small, but by introducing RF energy at the same time as the microwave energy, the potential difference between the plasma and the substrate (+ on the plasma side and − on the substrate side). Can be large. By thus increasing the plasma potential positively with respect to the substrate, active species decomposed by microwave energy are deposited on the substrate, and at the same time, + ions accelerated by the plasma potential collide on the substrate and collide with the substrate surface. It is considered that the relaxation reaction of is promoted to obtain a good quality deposited film. This effect is particularly remarkable when the deposition rate is several nm / sec or more.

Further, since RF has a high frequency unlike DC, the difference between the potential of plasma and the potential of the substrate is determined by the distribution of ionized ions and electrons. That is, the potential difference between the substrate and plasma is determined by the synergy of ions and electrons. Therefore, there is an effect that spark is unlikely to occur in the deposition chamber. As a result, stable glow discharge can be maintained for a long time of 10 hours or more.

In addition, since the flow rate and flow rate of the source gas change temporally or spatially when depositing a layer with a changed band gap, in the case of DC, the DC voltage is changed with time or spatially. Need to be changed appropriately.
However, in the deposited film forming method of the present invention, the ion ratio changes due to the temporal or spatial changes in the flow rate and flow rate of the source gas, and the RF self-bias automatically changes accordingly. Change. As a result, when RF is applied to the bias rod to change the raw material gas flow rate and the raw material gas flow rate ratio, the discharge is much more stable than in the case of DC bias.

In addition, in the deposited film forming method of the present invention, in order to obtain a desired change in band gap, a silicon atom-containing gas and a germanium atom-containing gas are mixed at a distance of 5 m or less from the deposition chamber. Preferably. When the raw material gases are mixed at a distance of more than 5 m, the raw material gas mixing positions are far apart even if the mass flow controller is controlled in response to a desired band gap change, and therefore the raw material gas delays or the mutual change of the raw material gases is prevented. Diffusion occurs, causing a shift with respect to the desired band gap. That is, if the mixing position of the raw material gas is too far away, the controllability of the band gap is deteriorated.

In addition to this, in order to change the hydrogen content contained in the i-type layer in the layer thickness direction, in the deposited film forming method of the present invention, RF is applied to the bias rod where the hydrogen content is to be increased. The RF energy applied to the bias rod may be reduced at the point where it is desired to increase the energy and reduce the hydrogen content. On the other hand, in the case of applying DC energy at the same time as RF energy, a DC voltage applied to the bias rod with a large positive polarity may be applied where the hydrogen atom content is desired to be increased, and when the hydrogen content is desired to be decreased. As for the DC voltage applied to the bias rod, a small voltage with positive polarity may be applied.

Next, the deposited film forming method of the present invention will be described in detail below.

[0067] First, the deposition chamber fitted with a substrate 1004 for forming the deposited film into the deposition chamber 1001 of FIG. 4-1 10 ^-5-to
Exhaust below the rr level. A turbo molecular pump is suitable for this exhaust, but an oil diffusion pump may be used. In the case of an oil diffusion pump, gases such as H ₂ , He, Ar, Ne, Kr, and Xe are introduced into the deposition chamber when the internal pressure of the deposition chamber 1001 becomes 10 ⁻⁴ or less so that oil does not diffuse back into the deposition chamber. Is good. After evacuation of the deposition chamber _{sufficiently, H 2, He, Ar,} Ne, Kr, a gas such as Xe, to be approximately equal to the deposition chamber internal pressure upon applying the raw material gas for forming the deposited film Introduce into the deposition chamber. The optimum pressure in the deposition chamber is 0.5 to 50 mTorr.

When the pressure in the deposition chamber becomes stable, the substrate heating heater 1005 is turned on and the substrate is heated to 100 to 500.
Heat to ℃. When the temperature of the substrate stabilizes at the specified temperature, H
Gases such as ₂ , He, Ar, Ne, Kr, and Xe are stopped, and a predetermined amount of raw material gas for forming a deposited film is introduced into the deposition chamber from a gas cylinder through a mass flow controller. The supply amount of the source gas for forming the deposited film introduced into the deposition chamber is
It is appropriately determined according to the volume of the deposition chamber. On the other hand, the internal pressure in the deposition chamber when the source gas for forming the deposited film is introduced into the deposition chamber is a very important factor in the deposited film forming method of the present invention, and the optimum internal pressure in the deposition chamber is 0. 5-
It is 50 mTorr.

Further, in the deposited film forming method of the present invention, microwave energy input into the deposition chamber for forming the deposited film is an important factor. The microwave energy is appropriately determined depending on the flow rate of the raw material gas introduced into the deposition chamber, but is smaller than the microwave energy required for 100% decomposition of the raw material gas, and a preferable range is as follows. , 0.02-1 W / cm ³
Is. A preferable frequency range of microwave energy is 0.5 to 10 GHz. Especially 2.4
A frequency around 5 GHz is suitable. Further, in order to form a deposited film with reproducibility by the deposited film forming method of the present invention and to form a deposited film over several hours to several tens of hours, frequency stability of microwave energy is very important. . The fluctuation of the frequency is preferably within ± 2%. Further, the ripple of the microwave is preferably within ± 2%.

Further, in the method of forming a deposited film of the present invention, the RF energy which is introduced into the deposition chamber at the same time as the microwave energy is a very important factor in combination with the microwave energy, and the RF energy is preferable. The range is 0.04 to 2 W / cm ³ . RF
1 to 100 MHz can be mentioned as a preferable frequency range. Particularly, 13.56 MHz is optimum. Also R
The fluctuation of the frequency of F is within ± 2%, and a smooth waveform is preferable.

The supply of the RF energy is appropriately selected according to the area ratio of the area of the bias rod for supplying the RF energy and the area of the ground. Particularly, the area of the bias rod for supplying the RF energy is the area of the ground. If it is narrower than this, it is preferable to ground the self-bias (DC component) on the power supply side for RF energy supply. Also, RF
When the self-bias (DC component) on the power supply side for energy supply is not grounded, it is preferable to make the area of the bias rod for RF energy supply larger than the area of the ground in contact with the plasma.

Such microwave energy is introduced into the deposition chamber from the waveguide section 1010 through the dielectric window 1002, and at the same time, RF energy is introduced into the deposition chamber from the bias power source 1011 through the bias rod 1012. In this state, the raw material gas is decomposed for a desired time to form a deposited film having a desired layer thickness on the substrate. After that, stop the input of microwave energy and RF energy, exhaust the deposition chamber,
After sufficiently purging with a gas such as H ₂ , He, Ar, Ne, Kr, and Xe, the deposited non-single-crystal semiconductor film is taken out from the deposition chamber.

In addition to the RF energy, a DC voltage may be applied to the bias rod 1012. Regarding the polarity of the DC voltage, it is preferable to apply the voltage so that the bias rod becomes positive. And the preferable range of the DC voltage is 10 to 300V.

The following compounds are suitable as the compound containing silicon atoms or germanium atoms and capable of being gasified, which is used for forming the deposited film of the i-type layer of the present invention as described above.

For example, as the gasifiable compound containing silicon atoms, SiH ₄ , Si ₂ H ₆ , SiF ₄ , S
iFH ₃ , SiF ₂ H ₂ , SiF ₃ H, Si ₃ H ₈ , Si
D ₄ , SiHD ₃ , SiH ₂ D ₂ , SiH ₃ D, SiFD ₃ ,
_{SiF 2 D 2, SiD 3 H} , etc. Si ₂ D ₃ H _3, and the like.

Specific examples of the compound containing a germanium atom and capable of being gasified include GeH ₄ , GeD ₄ , GeF ₄ ,
GeFH ₃ , GeF ₂ H ₂ , GeF ₃ H, GeHD ₃ , Ge
_{H 2 D 2, GeH 3 D} , Ge 2 H 6, Ge 2 D 6 , and the like.

Further, the above compounds were used as H ₂ , He, Ne and A.
It may be appropriately diluted with a gas such as r, Xe or Kr and introduced into the deposition chamber.

In the present invention, as the valence electron control agent introduced for controlling the valence electrons of the non-single crystal semiconductor layer, there are group III atoms and group V atoms of the periodic table. As a starting material effectively used for introducing a group III atom, specifically, for introducing a boron atom, B ₂ H ₆ , B
₄ H ₁₀ , B ₅ H ₉ , B ₅ H ₁₁ , B ₆ H ₁₀ , B ₆ H ₁₂ , B ₆ H ₁₄
And borohydrides such as BF ₃ , BCl ₃ , and the like. In addition to this, AlCl ₃ ,
GaCl ₃ , InCl ₃ , TlCl _{3 and the} like can also be mentioned.

Further, as the starting material for introducing the group V atom, specifically, for introducing a phosphorus atom, phosphorus hydride such as PH ₃ , P ₂ H ₄ or the like, PH ₄ I, PF ₃ , P
Phosphorus halides such as F ₅ , PCl ₃ , PCl ₅ , PBr ₃ , PBr ₅ and PI ₃ can be mentioned. In addition, AsH ₃ , As
_{F 3, AsCl 3, AsBr 3} , ASF 5, SbH 3, Sb
F ₃ , SbF ₅ , SbCl ₃ , SbCl ₅ , BiH ₃ , Bi
Other examples include Cl ₃ and BiBr ₃ .

Periodic table introduced into the i-type layer of the non-single-crystal semiconductor layer. The introduced amount of group III atoms and group V atoms is 1000.
A preferable range is ppm or less. Further, it is preferable to add them so that the group III atom and the group V atom of the periodic table are simultaneously compensated.

Further, the above compounds were used as H ₂ , He, Ne and A.
It may be appropriately diluted with a gas such as r, Xe or Kr and introduced into the deposition chamber. The most suitable gas for dilution is H ₂ , H
e.

FIG. 4-2 shows the RF of the photovoltaic element of the present invention.
It is a schematic explanatory view showing an example of a deposited film forming apparatus suitable for depositing an i-type layer by a plasma CVD method. The deposited film forming apparatus is a film forming apparatus 110 based on the RF glow discharge method.
0, deposition chamber 1101, cathode 1102, gas introduction pipe 1
103, substrate 1104, heater 1105, vacuum gauge 1106, conductance valve 1107, mechanical booster pump (not shown) after the conductance valve, auxiliary valve 1108, leak valve 1109, R
F power supply 1111, RF matching box 1112, raw material gas supply device 1020, mass flow controller 1
021 to 1029, gas introduction valves 1031 to 103
9, valves 1051 to 1059 of source gas cylinders, pressure regulators 1061 to 1069, source gas cylinders 1071
It is composed of 1079 and the like.

The i-type layer by the RF plasma CVD method inserted at the n / i interface of the photovoltaic device of the present invention is deposited as follows.

First, the substrate on which the n-type layer is deposited is placed in the deposition chamber 11
No. 01 heater 1105 is mounted as a substrate 1104. The door of the deposition chamber 1101 is closed and the inside of the deposition chamber is 10 ^-3 To
Pull up until it reaches the rr level. H ₂ , He, Ne, A
RF plasma CV using a substrate heating gas such as r, Xe, or Kr
Flow at the same flow rate and pressure as when performing D. At the same time, the substrate heating heater 1105 is turned on, and the temperature of the heating heater 1105 is set so as to reach a desired substrate temperature. When the substrate temperature reaches a desired temperature, the substrate heating gas is stopped and the desired source gas for forming the deposited film is supplied from the source gas supply device 1020 into the deposition chamber 1101 via the auxiliary valve 1108 and the gas introduction pipe 1103. Introduce.

After the internal pressure of the deposition chamber becomes a desired internal pressure by the source gas and becomes stable, a desired RF energy is introduced from the RF power source into the cathode electrode 1102 through the matching box 1112. Then, plasma is generated to continue the deposition for a desired deposition time. After the desired deposition time,
The supply of RF energy is stopped, the heater for heating the substrate is turned off, the raw material gas for forming the deposited film is stopped, and the deposition chamber is sufficiently purged. After the substrate temperature has dropped to about room temperature, the substrate is taken out of the deposition chamber and the next microwave plasma CV is performed.
Proceed to step D.

When depositing an i-type layer by the RF plasma CVD method, the substrate temperature in the deposition chamber is 100 to 350 ° C., the internal pressure is 0.1 to 10 Torr, and the RF power is 0.01.
~ 5.0 W / cm ³ , deposition rate is 0.01-2 nm /
sec is the optimum condition.

The frequency of RF is 1 MHz to 100 M
HZ is a suitable range, and particularly a frequency near 13.56 MHz is optimum. Further, in the RF method, the stability of the RF frequency is also a very important factor, and preferably ±
Within 2%. The RF power ripple is preferably 5% or less.

As a gas effectively used as a starting material for introducing nitrogen atoms or oxygen atoms into the i-type layer formed by the microwave plasma CVD method and the i-type layer formed by the RF plasma method, for example, a nitrogen atom-introduced gas is used. , N ₂ ,
_{NH 3, ND 3, NO,} NO 2, N 2 O , and the like. Further, as the oxygen atom introduction gas, O ₂ , CO, CO ₂ , N
_{O, NO 2, N 2 O} , CH 3 CH 2 OH, CH 3 OH , and the like.

As the deposition apparatus of the present invention, an apparatus in which a microwave plasma CVD apparatus and an RF plasma CVD apparatus are continuously connected is more preferable. The deposition chamber by the microwave plasma CVD method and the deposition chamber by the RF plasma CVD method are preferably separated by a gate. As the gate, a mechanical gate valve, a gas gate or the like is suitable.

In the present invention, when the p-type layer or the n-type layer has a laminated structure, a layer containing a group III element or / and a group V element as a main constituent element in the periodic table (doping layer A)
And a p-type layer or an n-type layer having a laminated structure of a layer containing a valence electron control agent and containing silicon atoms as a main constituent element (doving layer B) is the microwave plasma CVD apparatus or the RF plasma CVD apparatus. Can be done using.

The dobbing layer A is the same as the periodic table II.
It is preferable that a gas containing a group I element and / or a group V element is used as a source gas and deposited by the microwave plasma CVD method or the RF plasma CVD method. In particular, in order to reduce the hydrogen content of the doping layer A, it is preferable to decompose and deposit the source gas with as high a power as possible.

Also in the doping layer B, the microwave plasma CV is prepared by mixing a group III element and / or a group V element of the periodic table as a valence electron control agent with a silicon atom-containing gas.
It is preferable to deposit by the D method or the RF plasma CVD method.

On the other hand, when the doping layer B containing the crystal phase is deposited by the microwave plasma CVD method, it is preferable that the RF energy is smaller than the microwave energy and the microwave energy is relatively large. The preferred microwave energy is 0.1 to 1.5 W / cm ³ . Further, in order to increase the crystal grain size, it is preferable to dilute with hydrogen, and the dilution ratio of the source gas with hydrogen gas is preferably in the range of 0.01 to 10%.

Further, the dobbing layer B containing the crystal phase is formed by RF.
When depositing by the plasma CVD method, it is preferable that the silicon atom-containing gas is diluted to 0.01 to 10% with hydrogen gas (H ₂ , D ₂ ) and the RF power is set to 1 to 10 W / cm ^2. It is a condition.

When the p-type layer and / or the n-type layer of the photovoltaic element of the present invention is formed by stacking the doping layer A and the doping layer B, it is preferable to start from the doping layer B and end with the doping layer B. It is a thing. BA for example
B, BABAB, BABABAB, BABABABAB
The configuration such as is preferable.

Especially when the transparent electrode and the p-type layer and / or the n-type layer having a laminated structure are in contact with each other, the period of indium oxide or tin oxide forming the transparent electrode is better when the doping layer B is in contact with the transparent electrode. It is possible to prevent the diffusion of the group III element and / or the group V element of the index table and reduce the decrease over time in the photoelectric conversion efficiency of the photovoltaic element.

Next, the structure of the photovoltaic element of the present invention will be described in more detail. (Conductive Substrate) The conductive substrate may be a conductive material, or may be one in which a support is formed of an insulating material or a conductive material and then a conductive treatment is performed thereon. As the conductive support, for example, NiCr, stainless steel, Al,
Cr, Mo, Au, Nb, Ta, V, Ti, Pt, P
Examples include metals such as b and Sn, or alloys thereof.

As the electrically insulating support, a film or sheet of synthetic resin such as polyester, polyethylene, polycarbonate, cellulose acetate, polypropylene, polyvinyl chloride, polyvinylidene chloride, polystyrene and polyamide, or glass, ceramics, paper, etc. Is mentioned. These electrically insulating supports preferably have at least one surface thereof subjected to a conductive treatment,
It is desirable to provide a photovoltaic layer on the surface side that has been subjected to the conductive treatment.

For example, in the case of glass, N
iCr, Al, Cr, Mo, Ir, Nb, Ta, V, T
i, Pt, Pb, In ₂ O ₃ , ITO (In ₂ O ₃ + SnO
₂ ) Conductivity is provided by providing a thin film made of, for example, NiCr, Al, Ag, Pb, Zn, Ni, if it is a synthetic resin film such as polyester film.
Au, Cr, Mo, Ir, Nb, Ta, V, Tl, Pt
A metal thin film such as is provided on the surface by vacuum vapor deposition, electron beam vapor deposition, sputtering, or the like, or the surface is laminated with the metal to impart conductivity to the surface. The shape of the support may be a sheet having a smooth surface or an uneven surface. The thickness is appropriately determined so that a desired photovoltaic element can be formed, but when flexibility as a photovoltaic element is required, a range in which the function as a support is sufficiently exerted Can be made as thin as possible. However, it is usually 10 μm or more in terms of production, handling and mechanical strength of the support. (Light reflection layer) As the light reflection layer, Ag, Al, Cu, A
A metal having a high reflectance from visible light to near infrared is suitable such as 1Si. These metals are suitably formed by a resistance heating vacuum evaporation method, an electron beam vacuum evaporation method, a co-evaporation method, a sputtering method, or the like. As a layer thickness of these metals as a light reflecting layer, a suitable layer thickness is 10 nm to 5000 nm. In order to texture these metals, the substrate temperature at the time of depositing these metals should be 200 ° C. or higher. (Reflection increasing layer) As the reflection increasing layer, ZnO, SnO ₂ ,
In ₂ O ₃ , ITO, TiO ₂ , CdO, Cd ₂ SnO ₄ ,
Bi ₂ O ₃ , MoO ₃ , Na _x WO _{3 and the} like are most suitable.

Suitable methods for depositing the reflection-increasing layer include vacuum evaporation method, sputtering method, CVD method, spray method, spin-on method, dip method and the like.

Regarding the layer thickness of the reflection increasing layer, the optimum layer thickness varies depending on the refractive index of the material of the reflection increasing layer,
The preferable layer thickness range is 50 nm to 10 μm. To further texture the reflection enhancing layer, the substrate temperature when depositing the reflection enhancing layer is 300 ° C.
It is preferable to increase the above. (P-type layer or n-type layer: second and first conductivity type layers) The p-type layer or the n-type layer is an important layer that influences the characteristics of the photovoltaic element.

Examples of the amorphous material (denoted as a-) of the p-type layer or the n-type layer (a microcrystalline material (denoted as μc-) is also included in the category of amorphous materials) are, for example, a- Si:
H, a-Si: HX, a-SiC: H, a-SiC: H
X, a-SiGe: H, a-SiGeC: H, a-Si
O: H, a-SiN: H, a-SiON: HX, a-S
iOCN: HX, μc-Si: H, μc-SiC: H,
μc-Si: HX, μc-SiC: HX, μc-SiG
e: H, μc-SiO: H, μc-SiGeC: H, μ
c-SiN: H, μc-SiON: HX, μc-SiO
CN: HX, etc. p-type valence electron control agent (Periodic Table III
Examples include a material in which a group atom B, Al, Ga, In, Tl) or an n-type valence electron control agent (group V atom P, As, Sb, Bi in the periodic table) is added at a high concentration. (Poly
Is displayed), for example, poly-Si: H,
poly-Si: HX, poly-SiC: H, pol
y-SiC: HX, poly-SiGe: H, poly
-Si, poly-SiC, poly-SiGe, etc., a p-type valence electron control agent (group III atom B, Al,
Ga, In, Tl) and n-type valence electron control agents (group V atoms P, As, Sb, Bi of the periodic table) are added at high concentrations.

Particularly in the p-type layer or the n-type layer on the light incident side,
A crystalline semiconductor layer with little light absorption or an amorphous semiconductor layer with a wide band gap is suitable.

The amount of Group III atoms added to the p-type layer and the amount of Group V atoms added to the n-type layer are 0.1 to 0.1%.
The optimum amount is 50 at%.

Hydrogen atoms (H, D) or halogen atoms contained in the p-type layer or the n-type layer serve to compensate dangling bonds in the p-type layer or the n-type layer, It improves the doping efficiency of the layer. The optimum amount of hydrogen atoms or halogen atoms added to the p-type layer or the n-type layer is 0.1 to 40 at%. Especially p
When the type layer or the n-type layer is crystalline, the optimum amount of hydrogen atoms or halogen atoms is 0.1 to 8 at%. Further, a preferable distribution form is one in which the content of hydrogen atoms and / or halogen atoms is largely distributed on the interface side of each of the p-type layer / i-type layer and the n-type layer / i-type layer. The content of hydrogen atoms and / or halogen atoms is preferably in the range of 1.1 to 2 times the content in the bulk. Thus, by increasing the content of hydrogen atoms or halogen atoms in the vicinity of each interface of the p-type layer / i-type layer and the n-type layer / i-type layer, the defect level and mechanical strain near the interface are reduced. It is possible to increase the photovoltaic power and the photocurrent of the photovoltaic device of the present invention.

Regarding the electrical characteristics of the p-type layer and the n-type layer of the photovoltaic element, the activation energy is preferably 0.2 eV or less, and most preferably 0.1 eV or less. The specific resistance is preferably 100 Ωcm or less, and most preferably 1 Ωcm or less. Furthermore, the layer thickness of the p-type layer and the n-type layer is 1 to
50 nm is preferable and 3 to 10 nm is optimum.

As a source gas suitable for depositing the p-type layer or the n-type layer of the photovoltaic element, a gasifiable compound containing a silicon atom, a gasifiable compound containing a germanium atom, or a carbon atom was contained. Examples thereof include compounds that can be gasified, and mixed gases of the compounds.

Specific examples of the gasifiable compound containing a silicon atom include SiH ₄ , Si ₂ H ₆ and Si.
F ₄ , SiFH ₃ , SiF ₂ H ₂ , SiF ₃ H, Si ₃ H ₈ ,
SiD ₄ , SiHD ₃ , SiH ₂ D ₂ , SiH ₃ D, SiF
_{D 3, SiF 2 D 2,} SiD 3 H, etc. Si ₂ D ₃ H _3, and the like.

Specific examples of the gasifiable compound containing a germanium atom include GeH ₄ , GeD ₄ , and Ge.
F ₄ , GeFH ₃ , GeF ₂ H ₂ , GeF ₃ H, GeHD ₃ ,
_{GeH 2 D 2, GeH 3 D} , Ge 2 H 6, Ge 2 D 6 , and the like.

Specific examples of the gasifiable compound containing a carbon atom include CH ₄ , CD ₄ , C _n H _{2n + 2} (n is an integer), C _n H _2n (n is an integer), C ₂ H ₂ , C ₆ H ₆ , CO ₂ ,
CO etc. are mentioned.

The substances introduced into the p-type layer or the n-type layer for controlling the valence electrons are the periodic table group III source and group V source.
Group atoms can be mentioned.

As a starting material effectively used for introducing a group III atom, specifically, for introducing a boron atom, B ₂ H ₆ , B ₄ H ₁₀ , B ₅ H ₉ , B ₅ H ₁₁ , B ₆ H
₁₀ , B ₆ H ₁₂ , B ₆ H _14, etc. borohydrides, BF ₃ , BC
Examples thereof include boron halides such as l ₃ and the like.
In addition, AlCl ₃ , GaCl ₃ , InCl ₃ , TlC
Examples include l _{3 and the} like. B ₂ H ₆ and BF ₃ are particularly suitable.

What is effectively used as a starting material for introducing a group V atom is specifically PH for introducing a phosphorus atom.
₃ , Phosphorus hydride such as P ₂ H ₄ , PH ₄ I, PF ₃ , PF ₅ , PC
Examples thereof include phosphorus halides such as l ₃ , PCl ₅ , PBr ₃ , PBr ₅ , and PI ₃ . In addition, AsH ₃ , AsF ₃ , AsC
l ₃ , ASBr ₃ , ASF ₅ , SbH ₃ , SbF ₃ , Sb
F ₅ , SbCl ₃ , SbCl ₅ , BiH ₃ , BiCl ₃ , B
iBr ₃ etc. can also be mentioned. Particularly, PH ₃ and PF ₃ are suitable.

In addition, the gasifiable compound is replaced by H ₂ , H
It may be appropriately diluted with a gas such as e, Ne, Ar, Xe, or Kr and introduced into the deposition chamber.

The p-type layer or the n-type layer deposition method suitable for the photovoltaic device is the RF plasma CVD method and the microwave plasma CVD method.

Particularly when the deposition is performed by the RF plasma CVD method, the capacitive coupling type RF plasma CVD method is suitable.
When the p-type layer or the n-type layer is deposited by the RF plasma CVD method, the substrate temperature in the deposition chamber is 100 to 350 ° C., the internal pressure is 0.1 to 10 torr, and the RF power is 0.01 to.
5.0 W / cm ² , deposition rate is 0.1-30 A / se
c is mentioned as an optimal condition.

In particular, when depositing a layer having small light absorption or a wide bandgap such as a microcrystalline semiconductor or a-SiC: H, the source gas is diluted with hydrogen gas to 2 to 100 times, and the RF power is relatively high. It is preferable to introduce power. The suitable range of the RF frequency is 1 MHz to 100 MHz, and a frequency near 13.56 MHz is particularly suitable.

When the p-type layer or the n-type layer is deposited by the microwave plasma CVD method, the microwave plasma CVD apparatus introduces microwaves into the deposition chamber through a dielectric window (alumina ceramics or the like) by a waveguide. The method of doing is suitable.

The deposition film forming method of the present invention is also a suitable deposition method for depositing a p-type layer or an n-type layer by the microwave plasma CVD method, but it can be applied to a photovoltaic element under wider deposition conditions. It is possible to form various deposited films.

When a p-type layer or an n-type layer is deposited by a microwave plasma CVD method other than the method of the present invention, the substrate temperature in the deposition chamber is 100 to 400 ° C., and the internal pressure is 0.5 to 30.
mTorr, microwave power 0.01 to 1 W / cm
The frequency of ³ microwaves is preferably 0.5 to 10 GHz.

In particular, when depositing a layer having a small band of light absorption or a wide bandgap such as a microcrystalline semiconductor or a-SiC: H, the source gas is diluted 2 to 100 times with hydrogen gas, and the microwave power is relatively high. It is preferable to introduce high power. (I-Type Layer by Microwave Plasma CVD Method) In a photovoltaic device, the i-type layer is an important layer for generating and transporting carriers with respect to irradiation light.

As the i-type layer, it is possible to use only p-type and n-type layers. The i-type layer of the photovoltaic device of the present invention contains i-type silicon atoms and germanium atoms. The band gap changes smoothly in the layer thickness direction, and the minimum value of the band gap is offset from the central position of the i-type layer toward the interface between the p-type layer and the i-type layer. In the i-type layer, a material in which a valence electron control agent that serves as a donor and a valence electron control agent that serves as an acceptor are simultaneously doped is more suitable.

The hydrogen atom (H, D) or the halogen atom (X) contained in the i-type layer serves to compensate dangling bonds in the i-type layer, and the mobility and life of the carrier in the i-type layer. To improve the product of P-type layer / i-type layer, n-type layer /
It has a function of compensating for the interface state of each interface of the i-type layer, and has an effect of improving the photovoltaic power, the photocurrent and the photoresponsiveness of the photovoltaic device. The optimum content of hydrogen atoms and / or halogen atoms contained in the i-type layer is 1 to 40 at%.

In particular, a preferable distribution form is one in which the content of hydrogen atoms and / or halogen atoms is largely distributed on each interface side of the p-type layer / i-type layer and the n-type layer / i-type layer, The content of hydrogen atoms and / or halogen atoms near the interface is preferably in the range of 1.1 to 2 times the content in the bulk. Further, it is preferable that the hydrogen atom content and / or the halogen atom content is changed in the opposite direction to the increase / decrease direction of the silicon atom content. The content of hydrogen atoms and / or halogen atoms at the minimum content of silicon atoms is preferably in the range of 1 to 10 at%, and the content of hydrogen atoms and / or halogen atoms is 0.3 to 0. Eight times is the preferred range.

The content of hydrogen atoms and / or halogen atoms is changed in the direction opposite to the direction of the change of the content of silicon atoms, that is, in accordance with the band gap, hydrogen atoms and / or halogen atoms are formed in a narrow band gap. The atomic content is low. Although the details of the mechanism are unknown, according to the deposited film forming method of the present invention, in the deposition of an alloy-based semiconductor containing a silicon atom and a germanium atom, due to the difference in the ionization rates of the silicon atom and the germanium atom, It is considered that there is a difference in the energy acquired by the atoms, and as a result, even if the hydrogen content and / or the halogen content in the alloy-based semiconductor is low, the relaxation is sufficiently advanced and a good-quality alloy-based semiconductor can be deposited.

In addition, 100 pp of oxygen and / or nitrogen is added to the i-type layer containing silicon atoms and germanium atoms.
Addition of a small amount of m or less improves the durability against annealing due to long-term vibration of the photovoltaic element. The details of the cause are unknown, but since the composition ratio of silicon atoms and germanium atoms continuously changes in the layer thickness direction, it is better than when silicon atoms and germanium atoms are mixed at a constant ratio. It is considered that the residual strain tends to increase. By adding oxygen atoms and / or nitrogen atoms to such a system, structural strain can be reduced, and as a result, durability of the photovoltaic element against annealing due to long-term vibration is improved. it is conceivable that. As the distribution of oxygen atoms and / or nitrogen atoms in the layer thickness direction, a distribution that increases or decreases according to the content of germanium atoms is preferable. This distribution is the opposite of the distribution of hydrogen atoms and / or halogen atoms, but it is considered that such distribution is preferable because of the effect of removing structural strain and the effect of reducing dangling bonds. .

Furthermore, by distributing such hydrogen atoms (or / and halogen atoms) and oxygen atoms (or / and nitrogen atoms), the tail states of the valence band and the conduction band are smoothly and continuously connected. Is.

The layer thickness of the i-type layer largely depends on the structure of the photovoltaic element (for example, single cell, tandem cell, triple cell) and the bandgap of the i-type layer, but is 0.05-.
The optimum layer thickness is 1.0 μm.

The i-type layer containing silicon atoms and germanium atoms according to the deposited film forming method of the present invention has a small tail state on the valence band side even if the deposition rate is increased to 5 nm / sec or more. The inclination of the state is 6
It is 0 meV or less, and the density of dangling bonds by electron spin resonance (esr) is 10 ¹⁷ / cm ³ or less.

The band gap of the i-type layer is p-type layer / i
It is preferable to design so as to be wide on each interface side of the mold layer and the n-type layer / i-type layer. By designing in this way, the photovoltaic power and photocurrent of the photovoltaic element can be increased, and photodegradation and the like when used for a long time can be prevented. (I-type layer by RF plasma CVD method) RF plasma C
The i-type layer formed by the VD method is deposited at a deposition rate of 2 nm / sec or less, and the content of hydrogen atoms and / or halogen atoms contained in the deposited film is 1 to 40 at%.
The range of is preferable. The bonding state of hydrogen atoms and / or halogen atoms is preferably a state in which one hydrogen atom is bonded to a silicon atom or a state in which one halogen atom is bonded. The value obtained by dividing the full width at half maximum of the 2000 cm ^-1 peak in the infrared absorption spectrum showing the state where one hydrogen atom is bonded to the silicon atom by the peak height is the peak at 2000 cm ^-1 of the i-type layer by the microwave plasma CVD method It is preferable that the width is larger than the value obtained by dividing the half-value width of 1 by the peak height. (Transparent Electrode) As the transparent electrode, a transparent electrode made of indium oxide or indium oxide is suitable.

The transparent electrode is deposited as follows.
The sputtering method and the vacuum evaporation method are the most suitable deposition methods for depositing the transparent electrode.

In a magnetron sputtering apparatus, when a transparent electrode made of indium oxide is deposited on a substrate, a target made of metal indium (In) or indium oxide (In ₂ O ₃ ) is used. When a transparent electrode made of indium tin oxide is deposited on the substrate, the target is metallic tin (S
n), metallic indium or an alloy of metallic tin and metallic indium, tin oxide, indium oxide, indium-tin oxide, etc. are appropriately combined and used.

When depositing by the sputtering method, the substrate temperature is an important factor, and a preferable range is 25 ° C to 600 ° C. Examples of the gas for sputtering include inert gases such as argon gas (Ar), neon gas (Ne), xenon gas (Xe), and helium gas (He), and Ar gas is most suitable. Further, it is preferable to add oxygen gas (O ₂ ) to the inert gas as needed. Especially when a metal is used as a target, oxygen gas (O ₂ ) is essential.

Further, when the target is sputtered with the above-mentioned inert gas or the like, the pressure in the discharge space is 0.1 to 50 mTorr in order to perform the sputtering effectively.
r is mentioned as a preferable range.

As the power source, a DC power source and an RF power source are suitable. A suitable power range for the sputtering is 10 to 1000 W.

The deposition rate of the transparent electrode depends on the pressure in the discharge space and the discharge power, and the optimum deposition rate is 0.0
It is in the range of 1 to 10 nm / sec. The layer thickness of the transparent electrode is preferably deposited under conditions that satisfy the conditions of the antireflection film. As a specific layer thickness of the transparent electrode, 50 to 300 nm is mentioned as a preferable range.

Suitable vapor deposition sources for depositing transparent electrodes in the vacuum vapor deposition method include metal tin, metal indium,
An indium-tin alloy is mentioned. Moreover, the range of 25 ° C. to 600 ° C. is a suitable range for the substrate temperature when depositing the transparent electrode.

Further, when the transparent electrode is deposited, the deposition chamber is depressurized to the level of 10 ⁻⁶ torr or less and then oxygen gas (O ₂ )
Is required to be introduced into the deposition chamber in the range of 5 × 10 ⁻⁵ torr to 9 × 10 ⁻⁴ torr. By introducing oxygen in this range, the metal vaporized from the vapor deposition source reacts with oxygen in the vapor phase to deposit a good transparent electrode.

Further, RF power may be introduced at the above-mentioned degree of vacuum to generate plasma, and vapor deposition may be performed through the plasma. The preferable range of the deposition rate of the transparent electrode under the above conditions is 0.01 to 10 nm / sec. If the deposition rate is less than 0.01 nm / sec, the productivity will be reduced, and if it is more than 10 nm / sec, a rough film will be formed and the transmittance, the conductivity and the adhesion will be reduced.

Next, the power generation system of the present invention will be described.

The power generation system of the present invention supplies the above-described photovoltaic element of the present invention and the voltage and / or current of the photovoltaic element to the storage element and / or the external load from the photovoltaic element. And a storage battery for storing and / or supplying the power supplied from the photovoltaic element to an external load.

FIG. 9-1 is an example of the power supply system of the present invention, which is a basic circuit when only the photovoltaic element is used as a power source. An electromotive element 9001, a diode 9002 for controlling the voltage of the photovoltaic element, a capacitor 9003 for functioning as a storage battery and stabilizing the voltage, and a load 900.
It is composed of 4.

FIG. 9-2 is an example of the power supply system of the present invention, which is a basic charging circuit using a photovoltaic element. The circuit uses the photovoltaic device of the present invention as a solar cell 9101.
A backflow prevention diode 9102, a voltage control circuit 9103 for monitoring the voltage and controlling the voltage, and a secondary battery 91.
04, a load 9105, and the like. A silicon diode, a Schottky diode, or the like is suitable as the backflow prevention diode. Examples of the secondary battery include a nickel cadmium battery, a rechargeable silver oxide battery, a lead storage battery, a flywheel energy storage unit and the like. FIG. 9C shows an example of the voltage control circuit 9103. The voltage control circuit is almost equal to the output of the solar cell until the battery is fully charged, but when the battery is fully charged, the charging current is stopped by the charging control IC.

The solar cell system utilizing such photovoltaic power can be used as a power source for a battery charging system for automobiles, a battery charging system for ships, a streetlight lighting system, an exhaust system and the like.

FIG. 9-4 is a block diagram of a hybrid type power supply system of solar cells and diesel power generation. The power generation system includes a diesel generator 9401, a solar cell 9402, a rectifier 9403, a charge / discharge control device 94.
04, a storage battery 9405, a DC / AC converter 9406, a switch 9407, an AC load 9408, and the like.

Further, FIG. 9-5 is a block diagram of a commercial power source backup type solar cell power source system. The power supply system includes a solar cell 9501, a charge / discharge control device 9502, a storage battery 9503, a DC / AC converter 9504, a commercial power supply 9
505, a hitless switch 9506, a load 9507, and the like.

Furthermore, in addition to the above, FIG. 9-6 is a block diagram of a complete commercial power source interconnection type solar cell power source system. The power supply system includes a solar cell 9601, a DC / AC converter 960.
2, commercial power source 9603, load 9604, reverse power flow 9605
Etc.

As described above, the power supply system using the photovoltaic element of the present invention as a solar cell can be used stably for a long period of time, and even when the irradiation light applied to the solar cell varies. Since it sufficiently functions as an electromotive force element, it exhibits excellent stability.

[0149]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.

(Example 1) From the source gas supply apparatus 1020 and the deposition apparatus 1100 shown in FIG. 4A and the source apparatus 1020 and the deposition apparatus 1100 shown in FIG. RF
The photovoltaic element of the present invention was produced by the production apparatus using the plasma CVD method.

In the gas cylinders 1071 to 1079 in the figure, p made of the silicon-based non-single-crystal semiconductor material of the present invention is used.
A source gas for forming the mold layer, the i-type layer and the n-type layer is sealed, and 1071 is a SiH ₄ gas cylinder, 107
2 is an H ₂ gas cylinder, 1073 is a B ₂ H ₆ gas diluted with H ₂ gas to 10% (hereinafter abbreviated as “B ₂ H ₆ (10%) / H ₂ ”) cylinder, and 1074 is H ₂ gas. PH ₃ gas diluted to 1% (hereinafter abbreviated as “PH ₃ (1%) / H ₂ ”) cylinder, 1075 is Si ₂ H ₆ gas cylinder, 1076
Is a GeH ₄ gas cylinder and 1077 is H ₂ gas at 2000 p
BF ₃ gas diluted with pm (hereinafter abbreviated as “BF ₃ / H ₂ ”) cylinder, 1078 is H ₂ gas of 2000 ppm
PH ₃ gas diluted to (hereinafter “PH ₃ (2000 pp
m) / H ₂ "and abbreviated) bomb, 1079 NO gas (hereinafter abbreviated as" NO / He "that has been diluted to 1% with He gas) is cylinder. In addition, when attaching the gas cylinders 1071 to 1079 in advance,
Inflow valves 1031 to 1 from valves 1051 to 1059
It is introduced into the 039 gas pipe.

In the figure, 1004 and 1104 are substrates,
50 mm square, 1 mm thick stainless steel (SUS430B
A), the surface of which is mirror-finished, and a sputtering method is used to form a textured silver (Ag) thin film as a reflection layer of 100 nm, and a reflection-increasing layer of zinc oxide (Z).
The nO) thin film is vapor-deposited by 1 μm.

First, SiH ₄ gas from the gas cylinder 1071, H ₂ gas from the gas cylinder 1072, and gas cylinder 10
73 from B ₂ H ₆ / H ₂ gas, gas cylinder 1074 from P
H ₃ (1%) / H ₂ gas, Si ₂ from gas cylinder 1075
H ₆ gas, GeH ₄ gas from the gas cylinder 1076, BF ₃ / H ₂ from the gas cylinder 1077, PH ₃ (2000 ppm) / H ₂ from the gas cylinder 1078, NO / He from the gas cylinder 1079 are introduced by opening valves 1051 to 1059, Each gas pressure was adjusted to about 2 kg / cm ² by the pressure adjusters 1061 to 1069.

Next, it is confirmed that the inflow valves 1031 to 1039, the leak valves 1009 and 1109 of the deposition chambers 1001 and 1101 are closed, and the outflow valves 1041 to 1049 and the auxiliary valves 1008 and 11 are closed.
After confirming that 08 is opened, the conductance (butterfly type) valves 1007 and 1107 are fully opened, and the deposition chambers 1001 and 11 are opened by a vacuum pump (not shown).
01 and the gas pipe are evacuated, and vacuum gauges 1006 and 11
When the reading of 06 becomes about 1 × 10 ⁻⁴ Torr, auxiliary valves 1008 and 1108, outflow valves 1041 to 1
049 was closed. Next, inflow valves 1031 to 1039
Was gradually opened and each gas was introduced into the mass flow controllers 1021 to 1029.

After the preparation for film formation was completed as described above, an n-type layer, an i-type layer and a p-type layer were formed on the substrate by the RF plasma CVD method and the microwave plasma CVD method.

To form the n-type layer, the substrate 1004 is heated to 350 ° C. by the heater 1005, the outflow valves 1041 and 1044 and the auxiliary valve 1008 are gradually opened, and SiH ₄ gas and PH ₃ (1%) are added. / H ₂ gas was caused to flow into the deposition chamber 1001 through the gas introduction pipe 1003. At this time, the SiH ₄ gas flow rate is 50 sccm, PH
The mass flow controllers 1021 and 1024 were adjusted so that the flow rate of ₃ (1%) / H ₂ gas was 200 sccm. The pressure in the deposition chamber 1001 is 10 mTorr
The opening of the conductance valve 1007 was adjusted while observing the vacuum gauge 1006 so that

After that, the shutter 1013 is closed and the direct current (hereinafter abbreviated as "DC") of the bias power source 1011 is set.
The bias is set to 50 V and applied to the bias rod 1012, and then the power of the microwave power source (not shown) is set to 130 V.
mW / cm ³ is set, and the waveguide and the waveguide section 101 (not shown) are set.
0 and the dielectric window 1002, microwave power is introduced into the deposition chamber 1001 to generate microwave glow discharge, the shutter 1013 is opened, and n is formed on the substrate 1004.
The production of the mold layer was started, and an n-type layer having a layer thickness of 10 nm was prepared. After that, the shutter 1013 was closed to stop the microwave glow discharge, the outflow valves 1041 and 1044 and the auxiliary valve 1008 were closed to stop the gas inflow into the deposition chamber 1001, and the n-type layer production was completed.

Next, the substrate 1004 was taken out of the deposition chamber 1001 and placed in the deposition chamber 1101 of the deposition apparatus 1100 by the RF plasma CVD method shown in FIG. 4-2 to form an i-type layer by the RF plasma CVD method.

To form the i-type layer by the RF plasma CVD method, the substrate 1104 is heated to 350 ° C. by the heater 1105, the outflow valves 1041 and 1042 and the auxiliary valve 1108 are gradually opened, and SiH ₄ gas and H are added. ₂
Gas was introduced into the deposition chamber 1101 through the gas introduction pipe 1103. At this time, the SiH ₄ gas flow rate is 8 sccm,
The mass flow controllers 1021 and 1022 were adjusted so that the H ₂ gas flow rate was 100 sccm.
The conductance valve 11 is adjusted while observing the vacuum gauge 1106 so that the pressure in the deposition chamber 1101 becomes 0.5 Torr.
The aperture of 07 was adjusted.

After that, the power of the RF power supply 1111 is set to 120.
RF matching box 111 set to mW / cm ^2.
RF power is introduced to the cathode 1102 through the RF
RF plasma CVD on n-type layer by generating glow discharge
The formation of the i-type layer by the method is started, and when the i-type layer having a layer thickness of 10 nm is formed, the RF glow discharge is stopped, and the outflow valves 1041 and 1042 and the auxiliary valve 1108 are closed,
The gas flow into the deposition chamber 1101 is stopped and the RF plasma C
The formation of the i-type layer by the VD method is completed.

Next, the substrate 1104 was taken out from the deposition chamber 1101 and placed in the deposition chamber 1001 of the deposition apparatus 1000 by the microwave plasma CVD method shown in FIG. 4-1 to form an i-type layer by the microwave plasma CVD method. To produce an i-type layer by the microwave plasma CVD method,
The substrate 1004 is heated to 350 ° C. by the heater 1005, the outflow valves 1041, 1042, 1046 and the auxiliary valve 1008 are gradually opened, and SiH ₄ gas and H ₂ gas are added.
Gas and GeH ₄ gas were caused to flow into the deposition chamber 1001 through the gas introduction pipe 1003. At this time, the SiH ₄ gas flow rate is 200 sccm, the H ₂ gas flow rate is 500 sccm, and G
The mass flow controllers 1021, 1022, and 1046 were adjusted so that the eH ₄ gas flow rate was 1 sccm. The opening of the conductance valve 1007 was adjusted while observing the vacuum gauge 1006 so that the pressure in the deposition chamber 1001 became the value shown in Table 2.

Next, the shutter 1013 is closed, the power of the microwave power source (not shown) is set to 170 mW / cm ³ , and the waveguide, the waveguide portion 1010 and the dielectric window 10 (not shown) are set.
The microwave power is introduced into the deposition chamber 1001 through 02 to generate microwave glow discharge, and the bias power source 1
A high frequency (abbreviated as “RF” hereinafter) 011 bias was set to 350 mW / cm ³ and a DC bias was set to 0 V through a coil for RF cutting, and the bias rod 1
012 was applied. After that, the shutter 1013 is opened to start the production of the i-type layer by the microwave plasma CVD method on the i-type layer by the RF plasma CVD method, and at the same time, the SiH ₄ gas flow rate and the GeH ₄ gas flow rate are changed as shown in FIG.
After adjusting the mass flow controllers 1021 and 1026 according to the flow rate pattern shown in (1) to produce an i-type layer having a layer thickness of 300 nm, the shutter 1013 is closed, the output of the bias power supply 1011 is cut off, the microwave glow discharge is stopped, and the outflow occurs. Valves 1041, 1042, 10
46 and the auxiliary valve 1008 are closed and the deposition chamber 1001 is closed.
The gas flow to the inside was stopped.

Next, a p-type layer in which the doping layer A and the doping layer B were laminated was prepared.

To prepare the doped layer B1, the substrate 1
004 is heated to 300 ° C. by the heater 1005, the outflow valves 1041, 1042, 1047 and the auxiliary valve 1008 are gradually opened to deposit SiH ₄ gas, H ₂ gas, and BF ₃ / H ₂ gas through the gas introduction pipe 1003. It was made to flow into the chamber 1001. At this time, the SiH ₄ gas flow rate was 1 sccm, the H ₂ gas flow rate was 300 sccm, and BF ₃ /
The mass flow controllers 1021, 1022, and 1027 were adjusted so that the H ₂ gas flow rate was ₂ sccm. The opening of the conductance valve 1007 was adjusted while observing the vacuum gauge 1006 so that the pressure in the deposition chamber 1001 was 25 mTorr.

After that, the power of the microwave power source (not shown) is set to 50 mW / cm ³ , and the waveguide and the waveguide section 1 (not shown) are set.
Microwave power is introduced into the deposition chamber 1001 through 010 and the dielectric window 1002 to generate microwave glow discharge, the shutter 1013 is opened, and the production of the doping layer B1 on the i-type layer by the microwave plasma CVD method is started. Then, when the doping layer B1 having a layer thickness of 0.5 nm is produced, the shutter 1013 is closed to stop the microwave glow discharge, and the outflow valves 1041, 1042, and 1047.
The auxiliary valve 1008 was closed to stop the gas flow into the deposition chamber 1001.

Next, in order to form the doping layer A, the substrate 1004 is heated to 300 ° C. by the heater 1005, the outflow valve 1043 and the auxiliary valve 1008 are gradually opened, and B ₂ H ₆ (10%) / H ₂ gas was caused to flow into the deposition chamber 1001 through the gas introduction pipe 1003. At this time, the mass flow controller 1023 adjusted the B ₂ H ₆ / H ₂ gas flow rate to 100 sccm. The pressure inside the deposition chamber 1001 is adjusted to 30 mTorr while observing the vacuum gauge 1006 and the conductance valve 1007.
Adjusted the opening.

After that, the power of the microwave power source (not shown) is set to 50 mW / cm ³ , and the waveguide and the waveguide section 1 (not shown) are set.
Microwave power is introduced into the deposition chamber 1001 through 010 and the dielectric window 1002 to generate microwave glow discharge, the shutter 1013 is opened, and the doping layer B1 is formed.
When the fabrication of the doping layer A is started and the doping layer A having a layer thickness of 0.3 nm is produced, the shutter 1013 is formed.
To close the microwave glow discharge and shut off the outflow valve 10.
43 and the auxiliary valve 1008 are closed, and the deposition chamber 1001
The gas inflow was stopped.

Next, except that the layer thickness is 10 nm, the doping layer A is formed under the same manufacturing conditions as the above-mentioned doping layer B1.
A doping layer B2 was formed on top. When producing each layer, outflow valves 1041-10 other than required gas
Needless to say, 49 is completely closed, and the gas in each of the deposition chambers 1001 and 1101,
In order to avoid remaining in the pipes from the outflow valves 1041 to 1049 to the deposition chambers 1001 and 1101,
The outflow valves 1041 to 1049 are closed, and the auxiliary valve 10
08 and 1108 are opened, the conductance valves 1007 and 1107 are fully opened, and the system is temporarily evacuated to a high vacuum, if necessary.

Next, as a transparent electrode, IT was formed on the p-type layer.
A 0 (In ₂ 0 ₃ + SnO ₂ ) thin film having a thickness of 70 nm and an aluminum (Al) thin film having a thickness of 2 μm as a collector electrode were vacuum-deposited to produce a photovoltaic element (element Nos. 1-1 to 7,
Ratio 1-1).

Table 1 shows the manufacturing conditions of the above photovoltaic element. The initial characteristics, low illuminance characteristics, and durability characteristics of the photovoltaic elements manufactured in Example 1 (element No. Ex 1-1 to 7) and Comparative Example 1 (element No. ratio 1-1) were measured.

The initial characteristics were measured in Examples 1-1 to 7 (element No. 1-1 to 7) and Comparative Example 1 (element No. ratio 1-).
The photovoltaic element produced in 1) was replaced with AM-1.5 (100
mW / cm ² ) It was placed under irradiation with light and measured by the open circuit voltage and fill factor obtained by measuring the VI characteristic. The measurement results are shown in Table 2.

The measurement of the low illuminance characteristic was carried out in Example 1 (element No.
Examples 1-1 to 7) and Comparative Example 1 (element No. 1-1) were used for AM-1.5 (10 mW / cm).
² ) The photoelectric conversion efficiency, which was obtained by measuring the VI characteristics by placing the device under light irradiation, was used. The measurement results are shown in Table 2.

The durability characteristics were measured by measuring the photovoltaic elements manufactured in Example 1 (element No. 1-1 to 7) and Comparative Example 1 (element No. ratio 1-1) at a humidity of 70% and a temperature of 60 ° C. It was placed in a dark place, and was subjected to photoelectric conversion efficiency after applying a vibration of 1 mm at 3600 rpm for 48 hours. Table 2 shows the measurement results
Shown in.

As can be seen from Table 2, the pressure inside the deposition chamber 1001 is 50 when the i-type layer formed by the microwave plasma CVD method is used.
It has been found that a photovoltaic device having excellent characteristics can be obtained by manufacturing the device with mTorr or less.

Next, using a barium borosilicate glass (7059 manufactured by Corning Inc.) substrate, SiH ₄ gas flow rate, G
Except that the eH ₄ gas flow rate and the power of the microwave power source were set to the values shown in Table 3, the shutter 1013 was kept for 2 minutes under the same manufacturing conditions as the i-type layer of the above-mentioned element No. 1-5 by the microwave plasma CVD method. After opening, an i-type layer was formed on the substrate by the microwave plasma CVD method to prepare a sample for measuring the raw material gas decomposition efficiency (Sample No. 1-1 to No. 1).
5).

The layer thickness of the produced sample for measuring the decomposition efficiency of the source gas was measured by the layer thickness measuring device (TENCOR INSTRUUM).
The decomposition efficiency of the raw material gas was determined from the layer thickness by measuring with an ENTS alpha-step 100). The results are shown in Table 3.
Shown in.

Next, when the i-type layer was formed by the microwave plasma CVD method, except that the power of the microwave power source was set to the values shown in Table 4, the above-mentioned photovoltaic elements No. 1-5 were used. Under the same production conditions as above, a reflective layer, a transparent conductive layer, an n-type layer, an i-type layer, a p-type layer, a transparent electrode, and a collector electrode were produced on a substrate to produce a photovoltaic element (element No. 1-8 to 1
0 and ratios 1-2-3).

The produced photovoltaic element (element No. 1-8)
10 and ratios 1-2 to 3) were measured for initial characteristics, low illuminance characteristics and durability characteristics in the same manner as in the photovoltaic element No. 1-5 described above. The measurement results are shown in Table 4. Table 4
As can be seen from the above, it was found that by decomposing the raw material gas with microwave energy lower than the microwave energy required for 100% decomposition of the raw material gas, a photovoltaic element having excellent characteristics can be obtained.

Next, when the i-type layer was formed by the microwave plasma CVD method, the same production as that of the above-described element No. Ex 1-5 except that the RF bias was set to the value shown in Table 5. Under the conditions, a reflective layer, a transparent conductive layer, an n-type layer, an i-type layer, a p-type layer, a transparent electrode, and a collector electrode were formed on the substrate to prepare a photovoltaic element (Element No. 1-11). -14 and ratios 1-4).

The produced photovoltaic element (element No. 1-1
1-14 and the ratio 1-4) were measured for initial characteristics, low illuminance characteristics and durability characteristics in the same manner as in the above photovoltaic device. The measurement results are shown in Table 5. As can be seen from Table 5, it was found that by applying RF energy higher than microwave energy to the source gas, a photovoltaic element having excellent characteristics can be obtained.

Next, using a stainless steel substrate and a barium borosilicate glass (7059 manufactured by Corning Inc.) substrate, S
iH ₄ gas flow rate and GeH ₄ gas flow rate were set to the values shown in Table 6, under the same manufacturing conditions as the i-type layer by the microwave plasma CVD method of the above-mentioned element No. 1-5, i-type layer on the substrate, i A mold layer having a thickness of 1 μm was prepared to prepare samples for measuring physical properties (Sample Nos. 1-6 to 10).

Further, using a barium borosilicate glass (7059 manufactured by Corning Inc.) substrate, the above-mentioned element No. 1-5 was used.
An i-type layer having a thickness of 1 μm was formed on the substrate under the same conditions as those for forming the i-type layer by the RF plasma CVD method described above to prepare a sample for measuring physical properties (Sample No. 1-11).

The bandgap and composition of the prepared sample for measuring physical properties were analyzed to find the relationship between the bandgap and the composition ratio of Si atoms and Ge atoms. The band gap and the result of composition analysis are shown in Table 6. Here, the bandgap is measured by setting a glass substrate on which an i-type layer is prepared in a spectrophotometer (type 330 manufactured by Hitachi, Ltd.), measuring the wavelength dependence of the absorption coefficient of the i-type layer, and measuring the amorphous solar cell. The band gap of the i-type layer was determined by the method described in p109 of “Kiyo Takahashi and Seiko Konagai” (Shokodou Co., Ltd.). In the composition analysis, the stainless steel substrate on which the i-type layer was formed was placed in an Auger electron spectroscopy analyzer (JAMP-3 manufactured by JEOL Ltd.), and the composition ratio of Si atom and Ge atom was measured.

Next, when the i-type layer is formed by the microwave plasma CVD method, the SiH ₄ gas flow rate and the GeH ₄ gas flow rate are set by the mass flow controllers 1021 and 1026 according to the flow rate pattern shown in FIG. 5 (2). Except for the adjustment, the reflective layer, the transparent conductive layer, the n-type layer, the i-type layer, the p-type layer, and
A transparent electrode and a collecting electrode were produced to produce a photovoltaic element (element No. ratio 1-5).

The produced photovoltaic element having the element No. ratio 1-5 was measured for initial characteristics, low illuminance characteristics and durability characteristics in the same manner as in the element No. Ex 1-5. As a result of the measurement, the open-circuit voltage of the initial characteristics is 1.02 times and the fill factor is 1.03 times in the photovoltaic elements of element Nos. 1-5 compared to the photovoltaic elements of element No. 1-5. , Photoelectric conversion efficiency of low illuminance characteristics is 1.0
7 times, and the decrease in photoelectric conversion efficiency of durability characteristics was 1.08 times as excellent.

Next, element No. 1-5 and element No. 1
The composition analysis of Si atoms and Ge atoms in the layer thickness direction of the i-type layer of the photovoltaic device of No. -5 by the microwave plasma CVD method was performed by the same method as the composition analysis. Then, S obtained by the above-mentioned sample Nos. 1-6 to 10
From the relationship between the composition ratio of i atoms and Ge atoms and the bandgap, the change in the bandgap of the i-type layer in the layer thickness direction by the microwave plasma CVD method was obtained. The result is shown in FIG. As can be seen from FIG. 6, in the photovoltaic devices of Device Nos. 1-5, the position of the minimum value of the band gap is offset from the center position of the i-type layer toward the interface between the p-type layer and the i-type layer, In the photovoltaic element with the element No. ratio 1-5, it was found that the position of the minimum value of the band gap is offset from the central position of the i-type layer toward the interface between the n-type layer and the i-type layer.

When the i-type layer was formed by the RF plasma CVD method, the SiH ₄ gas flow rate and the RF discharge power were set to the values shown in Table 7, under the same manufacturing conditions as those of the element No. 1-5.
On the substrate, a reflective layer, a transparent conductive layer, an n-type layer, an i-type layer, a p-type layer, a transparent electrode, and a collector electrode were prepared to prepare a photovoltaic element. (Element No. 1 to 15-19, element No. ratio 1-
6) The produced photovoltaic element (element No. 1-15-1)
9, the element No. ratio 1-6) was measured for initial characteristics, low illuminance characteristics, and durability characteristics in the same manner as in Element No. Ex 1-5.
The results are shown in Table 7.

Next, an RF plasma of Element No. 1-5 except that a barium borosilicate glass (7059 manufactured by Corning Co., Ltd.) substrate was used and the SiH ₄ gas flow rate and the RF discharge power were set to the values shown in Table 7. An i-type layer was formed on the substrate at a desired deposition time under the same production conditions as the i-type layer by the CVD method, and a sample for deposition rate measurement was produced (Sample No.
1-12 to 17).

The deposition rate of the produced sample for deposition rate measurement was determined by the same method as in Samples No. 1-1 to No. 5. The results are shown in Table 7.

As can be seen from Table 7, it was found that a photovoltaic device having excellent characteristics can be obtained by producing the i-type layer by RF plasma CVD at a deposition rate of 2 nm / sec or less.

When the i-type layer was formed by the RF plasma CVD method, the film was formed on the substrate under the same production conditions as in Element No. 1-5 except that the layer thickness of the i-type layer was set to the value shown in Table 8. , A reflective layer, a transparent conductive layer, an n-type layer, an i-type layer, a p-type layer, a transparent electrode, and a collector electrode were produced to produce a photovoltaic element (element No. 1-20 to 22, element No. ratio). 1-7-8).

The produced photovoltaic element (element No. 1-2
0 to 22, element No. ratio 1-7 to 8), and element No. actual 1-5
The initial characteristics, the low illuminance characteristics, and the durability characteristics were measured by the same method.

The results are shown in Table 8. As can be seen from Table 8, the RF plasma CVD of the present invention having a layer thickness of 30 nm or less.
Photovoltaic device provided with i-type layer by the method (device No. 1-
20-22) has been found to have excellent properties.

Next, element No. Ex 1-5 except that the single crystal silicon substrate was used and the RF discharge power was set to the value shown in Table 9.
1 μm of the i-type layer formed by the RF plasma CVD method on the substrate under the same manufacturing conditions as the i-type layer formed by the RF plasma CVD method of FIG.
m to prepare infrared spectroscopic measurement samples (Sample Nos. 1-18 to 22). Furthermore, using a single crystal silicon substrate, microwave plasma CVD of element No. 1-5
An i-type layer of 1 μm was formed on the substrate by the microwave plasma CVD method under the same manufacturing conditions as the i-type layer by the method to prepare a sample for infrared spectroscopy measurement (Sample No. 1-2).
3).

The prepared infrared spectroscopic measurement samples (Sample Nos. 1-18 to 23) were converted into an infrared spectrophotometer (PERK).
INELMER product 1720-X), and the half-value width at the peak of 2000 cm ⁻¹ in the infrared absorption spectrum was divided by the height to obtain a value. The results are shown in Table 9.

Next, when the i-type layer was formed by the RF plasma CVD method, on the substrate under the same production conditions as those of the element No. Ex 1-5 except that the RF discharge power was set to the value shown in Table 9. Then, a reflective layer, a transparent conductive layer, an n-type layer, an i-type layer, a p-type layer, a transparent electrode, and a collector electrode were produced to produce a photovoltaic element (element No. 1-23 to 26).

The produced photovoltaic element (element No. 1-2
3 to 26) were measured for initial characteristics, low illuminance characteristics and durability characteristics in the same manner as in Element No. Ex 1-5. The results are shown in Table 9.

As can be seen from Table 9, the value obtained by dividing the full width at half maximum by the height at the peak of 2000 cm ^{−1 in} the infrared absorption spectrum is higher than that of the i-type layer formed by the microwave plasma CVD method and the i-type formed by the RF plasma CVD method. It has been found that photovoltaic devices with larger layers have excellent properties.

Next, when forming the p-type layer, except that the doping layer A was not formed and only the doping layer B was used, the same manufacturing conditions as those of the above-mentioned element No. 1-5 were used to form a p-type layer on the substrate. A photovoltaic layer was manufactured by manufacturing a reflective layer, a transparent conductive layer, an n-type layer, an i-type layer, a p-type layer, a transparent electrode, and a collector electrode (device No ratio 1-9).

The produced photovoltaic element having the element No. ratio 1-9 was measured for initial characteristics, low illuminance characteristics and durability characteristics in the same manner as in the element No. Ex 1-5. Measurement result, element No.
Compared with the photovoltaic element of ratio 1-9, the photovoltaic element of element No. 1-5 has an open circuit voltage of initial characteristics of 1.03, a fill factor of 1.02 times, and photoelectric conversion of low illuminance characteristics. Efficiency is 1.0
It was 9 times more excellent, and the decrease in photoelectric conversion efficiency of durability characteristics was 1.07 times better.

From the above measurement results, the internal pressure of the i-type layer formed by the microwave plasma CVD method of the present invention was 50 mTorr.
Below, the microwave energy lower than the microwave energy required to decompose 100% of the source gas, the RF energy acting on the source gas is higher than the microwave energy, the band gab changes smoothly in the layer thickness direction, The position of the minimum value of the band gap is offset from the central position of the i-type layer toward the interface between the p-type layer and the i-type layer, and the i-type layer formed by the RF plasma CVD method is 2 nm / se.
A layer having a deposition rate of c or less and a thickness of 30 nm or less, and at least one of the p-type layer and the n-type layer has a valence electron control with a layer containing a group III element or / and a group V element of the periodic table as a main constituent element. Photovoltaic device (device No. 1-1 to 26) manufactured by a laminated structure of layers containing a chemical agent and having silicon atoms as a main constituent element
However, it was found to have excellent characteristics with respect to the conventional photovoltaic device (device No ratio 1-1 to 9), and the effect of the present invention was verified.

(Example 2) SiH ₄ gas flow rate and Ge when forming an i-type layer by microwave plasma CVD method
The H ₄ gas flow rate is set to the mass flow controller 102 according to the flow rate pattern shown in FIG.
After adjusting 1 and 1026, the SiH ₄ gas flow rate was changed to 20.
0sccm, GeH ₄ gas flow rate is maintained at 1sccm,
A reflective layer, a transparent conductive layer, and a transparent conductive layer were formed on a substrate under the same manufacturing conditions as those of the element No. 1-5 of Example 1 except that the region having the maximum bandgap had the layer thickness shown in Table 10. A photovoltaic layer was produced by forming a mold layer, an i-type layer, a p-type layer, a transparent electrode, and a collector electrode (element No. 2-1 to 8).

The prepared photovoltaic element (element No. 2-1)
~ 8) were measured in the same manner as in Example 1 to measure the initial characteristics, low illuminance characteristics and durability characteristics. The results are shown in Table 10.
As can be seen from Table 10, it was found that the photovoltaic element (element No. 2-1 to 7) having a layer thickness of 1 to 30 nm in the bandgap maximum value region of the present invention has more excellent characteristics, The effect of the present invention was demonstrated.

Example 3 A BF ₃ / H ₂ gas cylinder 1077 was used when an i-type layer was formed by an RF plasma CVD method.
And PH ₃ (2000ppm) / H ₂ gas cylinder 1078
BF ₃ / H ₂ gas flow rate of 0.01 sccm, PH
_A reflective layer, a transparent conductive layer, an n-type layer, and an i-type were formed on a substrate under the same manufacturing conditions as the element No. Ex 1-5 of Example 1 except that the flow rate of ₃ (2000 ppm) / H ₂ gas was 0.5 sccm. layer,
A p-type layer, a transparent electrode, and a collector electrode were produced to produce a photovoltaic element (element No. 3).

When the photovoltaic element manufactured in Example 3 (element No. 3) was measured for initial characteristics, low illuminance characteristics and durability characteristics in the same manner as in Example 1, the element N of Example 1 was obtained.
The same initial characteristics, low illuminance characteristics, and durability characteristics as those of Ex 1-5 were obtained, and the effect of the present invention was verified.

Example 4 PH ₃ (2000 ppm) / H ₂ was used when an i-type layer was formed by the RF plasma CVD method.
AsH ₃ gas diluted to 2000 ppm with H ₂ gas instead of a gas cylinder (hereinafter abbreviated as “AsH ₃ / H ₂ ”)
A reflecting layer, a transparent conductive layer, an n-type layer, an i-type layer, a p-type layer were formed on the substrate under the same manufacturing conditions as in Example 3 except that a gas was used and the AsH ₃ / H ₂ gas was flowed at 0.5 sccm. Transparent electrode,
A collector electrode was prepared and a photovoltaic element was prepared (element No.
Actual 4).

When the initial characteristics, the low illuminance characteristics and the durability characteristics of the photovoltaic element manufactured in Example 4 (element No. 4) were measured by the same method as in Example 3, the element N of Example 3 was measured.
The same initial characteristics, low illuminance characteristics, and durability characteristics as those of Ex 3 were obtained, and the effect of the present invention was verified.

(Embodiment 5) When producing an i-type layer by the microwave plasma CVD method and the RF plasma CVD method, a NO / He gas cylinder 1079 is used and NO / He is used.
Element N of Example 1 except that the gas flow rate was 0.5 sccm for the i-type layer formed by the microwave plasma CVD method and 0.05 sccm for the i-type layer formed by the RF plasma CVD method.
o Under the same production conditions as in Ex 1-5, a reflective layer, a transparent conductive layer, an n-type layer, an i-type layer, a p-type layer, a transparent electrode, and a collector electrode are produced on a substrate to produce a photovoltaic element. (Element No. 5).

The produced photovoltaic element (element No. 5) was measured for initial characteristics, low illuminance characteristics and durability characteristics in the same manner as in Example 1. As a result, element No. 1-5 of Example 1 was measured.
Similar initial characteristics, low illuminance characteristics, and durability characteristics were obtained.

The photovoltaic element of Example 5 (element No. 5) was replaced with a secondary ion mass spectrometer (CAMECA I
Composition analysis by MS-3F) confirmed that the i-type layer contained oxygen atoms and nitrogen atoms. From the above results, the effect of the present invention was verified.

Example 6 When an i-type layer was formed by the microwave plasma CVD method, a Si ₂ H ₆ gas cylinder (not shown) was used, the Si ₂ H ₆ gas flow rate was set to 40 sccm, and S
The iH ₄ gas flow rate was adjusted by the mass flow controller 1021 according to the flow rate pattern shown in FIG. 7A, under the same manufacturing conditions as those of the element No. 1-5 of Example 1, the reflective layer and the transparent conductive layer were formed on the substrate. , An n-type layer, an i-type layer, a p-type layer, a transparent electrode, and a collector electrode were formed to fabricate a photovoltaic element (element No. 6).

The produced photovoltaic element (element No. 6) was measured for initial characteristics, low illuminance characteristics and durability characteristics in the same manner as in Example 1. Element No. 1-5 of Example 1 was measured.
Similar initial characteristics, low illuminance characteristics, and durability characteristics were obtained.

The distribution of Si atoms and hydrogen atoms in the i-type layer of the photovoltaic element of Example 6 (element No. 6) in the layer thickness direction was measured by a secondary ion mass spectrometer (IMS-3F manufactured by CAMECA). ). The result is shown in Figure 7 (2).
Shown in.

From the above results, the effect of the present invention was verified.

Example 7 Example 1 was repeated except that the distance between the point 1014 at which SiH ₄ gas and GeH ₄ gas were mixed and the deposition chamber 1001 in the source gas supply apparatus 1020 was set to the value shown in Table 11. Element No. 1-5 under the same manufacturing conditions as above, the reflective layer, the transparent conductive layer, the n-type layer, and the
A photovoltaic layer was produced by forming a mold layer, a p-type layer, a transparent electrode, and a collector electrode (element No. 7-1 to 5).

The produced photovoltaic element (element No. 7-1
5) were measured in the same manner as in Example 1 to measure initial characteristics, low illuminance characteristics and durability characteristics. The measurement results are shown in Table 11. As can be seen from Table 11, it was found that by setting the distance between the point 1014 at which SiH ₄ gas and GeH ₄ gas are mixed and the deposition chamber 1001 to be 5 m or less, a photovoltaic element with good characteristics can be obtained. .

(Embodiment 8) Element No. Ex 1-5 of Embodiment 1
A photovoltaic element was produced under the same production conditions as above, and using this, a solar cell module was produced, and an analog timepiece having a circuit configuration as shown in FIG. 9-2 was produced. In FIG. 9-2, the electric power generated in the solar cell module 9101 is charged in the secondary battery 9104 through the backflow prevention diode 9102. Reference numeral 9103 is an overcharge prevention diode.

Electric power from the solar cell module 9101 and the secondary battery 9104 is supplied to the analog timepiece driving circuit 910.
5 is supplied.

(Comparative Example 2) A photovoltaic element was produced under the same production conditions as the element No. 1-7 of Comparative Example 1, and using this, an analog timepiece similar to that of Example 8 was produced.

When the analog timepieces manufactured in Example 8 and Comparative Example 2 were installed on the wall in the room and the interior light was turned on for 8.5 hours every day, the analog timepiece of Example 8 operated all day, but Comparative Example 2 The analog timepiece of No.1 did not move all day, demonstrating the effect of the power generation system according to the present invention.

(Embodiment 9) When an i-type layer is formed by the microwave plasma CVD method, SiH ₄ gas flow rate and G
Except that the eH ₄ gas flow rate was adjusted by the mass flow controllers 1021 and 1026 according to the flow rate pattern shown in FIG. 8, under the same manufacturing conditions as the element No. 1-5 of Example 1,
On the substrate, a reflective layer, a transparent conductive layer, an n-type layer, an i-type layer, a p-type layer, a transparent electrode, and a collector electrode were produced to produce a photovoltaic element (element No. 9).

The produced photovoltaic element (element No. 9) was measured for initial characteristics, low illuminance characteristics and durability characteristics in the same manner as in Example 1. Element No. 1-5 of Example 1 was measured.
Similar initial characteristics, low illuminance characteristics and durability characteristics can be obtained,
The effect of the present invention was demonstrated.

(Example 10) When an i-type layer was formed by the RF plasma CVD method, a B ₂ H ₆ gas diluted to 2000 ppm with H ₂ gas instead of the BF ₃ / H ₂ gas cylinder (hereinafter referred to as "B ₂ H ₆ (2000 ppm) / H ₂ ”) cylinder is used, and B ₂ H ₆ (2000 ppm) / H ₂ gas is used for 0.05 s in the i-type layer formed by the RF plasma CVD method.
A reflective layer, a transparent conductive layer, an n-type layer, and a
The i-type layer, the p-type layer, the transparent electrode, and the collector electrode were produced to produce a photovoltaic element (element No. 10).

The manufactured photovoltaic element (element No. 10)
In the same manner as in Example 1, the initial characteristics, the low illuminance characteristics, and the durability characteristics were measured.
The initial characteristics, low illuminance characteristics and durability characteristics similar to those of No. 5 were obtained, and the effect of the present invention was verified.

(Embodiment 11) Microwave plasma CVD
When producing an i-type layer by the method, NO / He gas is used as shown in FIG.
0 (1) according to the flow rate pattern, except that it was adjusted by the mass flow controller 1029, under the same manufacturing conditions as the element No. 1-5 of Example 1, on the substrate, the reflective layer, the transparent conductive layer, the n-type layer, The i-type layer, the p-type layer, the transparent electrode, and the current-collecting electrode were produced to produce a photovoltaic element (element No. 1).
1).

The manufactured photovoltaic element (element No. 11)
In the same manner as in Example 1, the initial characteristics, the low illuminance characteristics, and the durability characteristics were measured.
The initial characteristics, low illuminance characteristics, and durability characteristics similar to those of No. 5 were obtained.

The distribution of nitrogen atoms and oxygen atoms in the i-type layer of the photovoltaic element of Example 11 (element No. 11) in the layer thickness direction was measured by a secondary ion mass spectrometer (CAMEC).
It was analyzed by IMS-3F manufactured by A). The result is shown in FIG.
It shows in (2).

From the above results, the effect of the present invention was verified.

(Example 12) Microwave plasma CVD
When the i-type layer is produced by the method, the SiH ₄ gas flow rate and the GeH ₄ gas flow rate are adjusted by the mass flow controllers 1021 and 1026 according to the flow rate pattern shown in FIG. 11, and the i-type layer is produced by the microwave plasma CVD method. Then, the i-type layer 2 formed by the RF plasma CVD method is shown in Table 1.
The reflective layer, the transparent conductive layer, the n-type layer, and the i-type layer were formed on the substrate under the same production conditions as in Example 3 except that the production was performed under the production conditions shown in 2.
A photovoltaic layer was fabricated by fabricating a mold layer, a p-type layer, a transparent electrode, and a collector electrode (element No. 12).

The manufactured photovoltaic element (element No. 12)
In the same manner as in Example 3, the initial characteristics, the low illuminance characteristics and the durability characteristics were measured. As a result, the same initial characteristics, the low illuminance characteristics and the durability characteristics as those of the element No. 3 of Example 3 were obtained. The effect of was proved.

(Example 13) Under the same manufacturing conditions as in Element No. 1-5 of Example 1, except that the layer thickness of the doping layer A was set to the value shown in Table 13 when manufacturing the p-type layer, On the substrate, a reflective layer, a transparent conductive layer, an n-type layer, an i-type layer, a p-type layer, a transparent electrode, and a current-collecting electrode were produced to produce a photovoltaic element (element No. 13-1 to 5). .

The produced photovoltaic element (element No. 13-
1 to 5) were measured for initial characteristics, low illuminance characteristics and durability characteristics in the same manner as in Example 1. The results are shown in Table 13. As can be seen from Table 13, the photovoltaic device (device No.) in which the layer thickness of the doping layer A of the present invention is 0.01 to 1 nm.
It was found that the fruits 13-1 to 5) have excellent characteristics,
The effect of the present invention was demonstrated.

Example 14 Same as Element No. 1-5 of Example 1 except that the doping layer A and the doping layer B were manufactured under the manufacturing conditions shown in Table 14 when manufacturing the n-type layer. Under the manufacturing conditions, a reflective layer, a transparent conductive layer, an n-type layer, an i-type layer, a p-type layer, a transparent electrode, and a collector electrode were prepared on a substrate to prepare a photovoltaic element (element No. 14). .

The produced photovoltaic element (element No. 14)
The initial characteristics, low illuminance characteristics and durability characteristics were measured by the same method as in Example 1, and the same initial characteristics, low illuminance characteristics and durability characteristics as in Example 1 were obtained, demonstrating the effect of the present invention. It was

Example 15 Same as Element No. 1-5 of Example 1 except that the doping layer A and the doping layer B were manufactured under the manufacturing conditions shown in Table 15 when manufacturing the p-type layer. Under the manufacturing conditions, a reflective layer, a transparent conductive layer, an n-type layer, an i-type layer, a p-type layer, a transparent electrode, and a collector electrode were formed on a substrate to prepare a photovoltaic element (element No. 15). .

The manufactured photovoltaic element (element No. 15)
The initial characteristics, low illuminance characteristics and durability characteristics were measured by the same method as in Example 1, and the same initial characteristics, low illuminance characteristics and durability characteristics as in Example 1 were obtained, demonstrating the effect of the present invention. It was

(Example 16) Microwave plasma CVD
Bias power supply 1011 when an i-type layer is produced by the method
Example 9 except that the RF bias was set to 250 mW / cm ³ and the DC bias was set to 50 V via a coil for RF cutting and applied to the bias rod 1012.
Under the same manufacturing conditions as above, a reflective layer, a transparent conductive layer, n
A photovoltaic element was produced by producing a mold layer, an i-type layer, a p-type layer, a transparent electrode, and a collector electrode (element No. 16).

The manufactured photovoltaic element (element No. 16)
When the initial characteristics, the low illuminance characteristics and the durability characteristics were measured by the same method as in Example 9, the same initial characteristics, the low illuminance characteristics and the durability characteristics as in Example 9 were obtained, and the effect of the present invention was verified. It was

(Example 17) Microwave plasma CVD
In making the i-type layer by law, using D ₂ gas cylinder, not shown, instead of H ₂ gas cylinder, 300Sc the D ₂ gas
under the same manufacturing conditions as the element No. 1-5 of Example 1 except that a flow of 10 cm is performed, a reflective layer, a transparent conductive layer, an n-type layer, and i are formed on the substrate.
A photovoltaic layer was produced by forming a mold layer, a p-type layer, a transparent electrode, and a collector electrode (element No. 17).

The manufactured photovoltaic element (element No. 17)
In the same manner as in Example 1, the initial characteristics, the low illuminance characteristics, and the durability characteristics were measured.
The initial characteristics, low illuminance characteristics, and durability characteristics similar to those of No. 5 were obtained.

The manufactured Example 17 (element No. 1)
The photovoltaic element of 7) is used as a secondary ion mass spectrometer (CA
When the composition was analyzed by IMS-3F manufactured by MECA,
It was confirmed that the D atom was contained in the i-type layer by the microwave plasma CVD method. From the above results, the effect of the present invention was verified.

(Embodiment 18) The DC bias of the bias power supply 1011 was applied to the shutter 10 when the n-type layer was formed.
At the same time that 13 is opened, the reflective layer, the transparent conductive layer, the n-type layer, and the The i-type layer, the p-type layer, the transparent electrode, and the collector electrode were produced to produce a photovoltaic element (element No. 18).

The manufactured photovoltaic element (element No. 18)
In the same manner as in Example 1, the initial characteristics, the low illuminance characteristics, and the durability characteristics were measured.
The initial characteristics, low illuminance characteristics and durability characteristics similar to those of No. 5 were obtained, and the effect of the present invention was verified.

(Example 19) The photovoltaic device of the present invention was manufactured in the same procedure as the i-type layer by the RF plasma CVD method of Example 1 using the manufacturing apparatus by the RF plasma CVD method shown in FIG. 4-2. N-type layer and p-type layer were prepared.

To form the n-type layer, the substrate 1104 is heated to 350 ° C. by the heater 1105, and the outflow valves 1042, 1044, 1045 and the auxiliary valve 110 are heated.
8 was gradually opened, and H ₂ gas, PH ₃ (1%) / H ₂ gas, and Si ₂ H ₆ gas were caused to flow into the deposition chamber 1101 through the gas introduction pipe 1103. At this time, the H ₂ gas flow rate is 50
sccm, PH ₃ (1%) / H ₂ gas flow rate is 5 sccm,
The mass flow controllers 1022, 1024, and 1025 were adjusted so that the Si ₂ H ₆ gas flow rate was 3 sccm. The pressure inside the deposition chamber 1101 was adjusted to 1 Torr by adjusting the opening of the conductance valve 1107 while watching the vacuum gauge 1106.

After that, the power of the RF power supply 1111 is set to 120.
RF matching box 1112 with mW / cm ² set
RF power is introduced to the cathode 1102 through the cathode to generate an RF glow discharge, the formation of an n-type layer is started on the substrate 1104, and an n-type layer having a layer thickness of 10 nm is formed.
Stop the glow discharge and spill valves 1042, 1044, 1
045 and the auxiliary valve 1108 are closed and the deposition chamber 110 is closed.
The gas flow into the inside of No. 1 was stopped, and the formation of the n-type layer was completed.

Next, under the same manufacturing conditions as the element No. Ex 1-5 of Example 1, i was formed by RF plasma CVD on the n-type layer.
A mold layer was prepared. Subsequently, the substrate 1104 on which the i-type layer was formed by the RF plasma CVD method was taken out from the deposition chamber 1101 and placed in the same deposition apparatus 1000 by the microwave plasma CVD method as in Example 1, and the element No. of Example 1 was used.
An i-type layer was formed by the microwave plasma CVD method on the i-type layer formed by the RF plasma CVD method under the same production conditions as in Example 1-5.

Next, the substrate 1004 having the i-type layer formed by the microwave plasma CVD method is taken out from the deposition chamber 1000, and the deposition apparatus 1 by the RF plasma CVD method described above is taken out.
It is installed at 100 and i by microwave plasma CVD method
A p-type layer was prepared by stacking a doping layer A and a doping layer B on the mold layer.

To prepare the doped layer B, the substrate 11
04 is heated to 200 ° C. by the heater 1105,
Outflow valves 1041, 1042, 1047 and 1108
Was gradually opened, and SiH ₄ gas, H ₂ gas, and BF ₃ / H ₂ gas were caused to flow into the deposition chamber 1101 through the gas introduction tube 1103. At this time, the SiH ₄ gas flow rate is 0.03 scc
m, H ₂ gas flow rate was 100 sccm, and BF ₃ / H ₂ gas flow rate was 1 sccm. The pressure inside the deposition chamber 1101 was adjusted to 1 Torr by adjusting the opening of the conductance valve 1107 while watching the vacuum gauge 1106.

After that, the power of the RF power supply 1111 is set to 2 W /
cm ² is set, RF power is introduced to the cathode 1102 through the RF matching box 1112, RF glow discharge is generated, and i by microwave plasma CVD method is applied.
Starting the production of the doping layer B1 on the mold layer, the layer thickness 0.3
The RF glow discharge is stopped when the doped layer B1 having a thickness of 10 nm is produced, and the outflow valves 1041, 1042, and 1047 are discharged.
The auxiliary valve 1108 was closed to stop the gas flow into the deposition chamber 1101.

Next, in order to form the doping layer A, the substrate 1104 is heated to 200 ° C. by the heater 1105, the outflow valve 1043 and the auxiliary valve 1108 are gradually opened, and B ₂ H ₆ (10%) / H ₂ gas was caused to flow into the deposition chamber 1101 through the gas introduction pipe 1103. At this time, the mass flow controller 1023 adjusted the B ₂ H ₆ (10%) / H ₂ gas flow rate to be 50 sccm. The opening of the conductance valve 1107 was adjusted while observing the vacuum gauge 1106 so that the pressure in the deposition chamber 1101 was 1 Torr.

After that, the power of the RF power supply 1111 is set to 3 W /
cm ² and RF power is introduced into the cathode 1102 through the RF matching box 1112 to cause RF glow discharge, and the doping layer A is formed on the doping layer B1.
Was started, and when the doping layer A having a layer thickness of 0.1 nm was prepared, the RF glow discharge was stopped and the outflow valve 10
48 and the auxiliary valve 1108 are closed and the deposition chamber 1101
The gas flow to the inside was stopped.

Next, the SiH ₄ gas flow rate is changed to 0.5 sccc.
m, BF ₃ / H ₂ gas flow rate 10 sccm, layer thickness 5 nm
A doping layer B2 was formed on the doping layer A under the same manufacturing conditions as the above-described doping layer B1 except for the above.

Finally, the element No. of Example 1 was formed on the p-type layer.
A transparent electrode and a collector electrode were vapor-deposited in the same manner as Example 1-5 to fabricate a photovoltaic element (Element No. Example 19).

Table 16 shows the conditions for manufacturing the above photovoltaic element.
Shown in.

Comparative Example 3 A reflective layer, a transparent conductive layer, an n-type layer and an i-type layer were formed on a substrate under the same manufacturing conditions as in Example 19 except that the i-type layer formed by the RF plasma CVD method was not provided.
A p-type layer, a transparent electrode, and a collector electrode were prepared to prepare a photovoltaic device (device No ratio 3).

The photovoltaic elements produced in Example 19 (element No. 19) and Comparative Example 3 (element No. ratio 3) were used in Example 1
The initial characteristics, the low illuminance characteristics, and the durability characteristics were measured by the same method. As a result of the measurement, the open-circuit voltage of the initial characteristics of the photovoltaic element of Example 19 (element No. 19) is 1.02 times that of the photovoltaic element of Comparative Example 3 (element No. 3), and the curve The factor is 1.03 times, and the photoelectric conversion efficiency of low illuminance characteristics is 1.
The effect of the present invention was proved to be excellent by 09 times and the decrease in photoelectric conversion efficiency of durability characteristics by 1.07 times.

(Example 20) Under the manufacturing conditions shown in Table 17,
By the same method as in Example 1, the reflective layer, the transparent conductive layer, the first n-type layer, the first i-type layer, the first p-type layer, and
A second n-type layer, a second i-type layer, a second p-type layer, a transparent electrode, and a collector electrode were produced to produce a photovoltaic element (element No. 20).

(Comparative Example 4) A reflective layer, a transparent conductive layer, and a first n-type layer were formed on a substrate under the same production conditions as in Example 20, except that the i-type layer was not produced by the first RF plasma CVD method. Layer, first i-type layer, first p-type layer, second n-type layer, second
The i-type layer, the second p-type layer, the transparent electrode, and the collector electrode were prepared to prepare a photovoltaic device (device No ratio 4).

The photovoltaic elements fabricated in Example 20 (element No. 20) and Comparative Example 4 (element No. ratio 4) were used in Example 1
The initial characteristics, the low illuminance characteristics, and the durability characteristics were measured by the same method. As a result of the measurement, as compared with the photovoltaic element of Comparative Example 4 (element No. ratio 4), the photovoltaic element of Example 20 (Element No. 20) has an initial open circuit voltage of 1.03 times and a curved line. The factor is 1.02 times, and the photoelectric conversion efficiency of low illuminance characteristics is 1.
09 times, the decrease in photoelectric conversion efficiency of durability characteristics was excellent by 1.06 times, demonstrating the effect of the present invention.

Example 21 Under the manufacturing conditions shown in Table 18,
By the same method as in Example 1, the reflective layer, the transparent conductive layer, the first n-type layer, the first i-type layer, the first p-type layer, and
Second n-type layer, second i-type layer, second p-type layer, third n-type layer
A photovoltaic layer was fabricated by fabricating the mold layer, the third i-type layer, the third p-type layer, the transparent electrode, and the collector electrode (element No. 2).
1).

Comparative Example 5 Example 21 is repeated except that the i-type layer is not formed by the first and second RF plasma CVD methods.
Under the same manufacturing conditions as above, the reflective layer, the transparent conductive layer, the first n-type layer, the first i-type layer, the first p-type layer, the second n-type layer, and the second i-type are formed on the substrate. Layer, second p-type layer, third n-type layer, third
The i-type layer, the third p-type layer, the transparent electrode, and the current collecting electrode were prepared to prepare a photovoltaic device (device No ratio 5).

The photovoltaic elements produced in Example 21 (element No. Ex. 21) and Comparative Example 5 (element No. No. 5) were used in Example 1
The initial characteristics, the low illuminance characteristics, and the durability characteristics were measured by the same method. As a result of the measurement, as compared with the photovoltaic element of Comparative Example 5 (element No. ratio 5), the photovoltaic element of Example 21 (Element No. Ex. 21) had an initial characteristic open circuit voltage of 1.03 times and a curved line. The factor is 1.03 times, and the photoelectric conversion efficiency of low illuminance characteristics is 1.
The effect of the present invention was proved to be 07 times more excellent and the decrease in photoelectric conversion efficiency of durability characteristics being 1.09 times more excellent.

Example 22 A photovoltaic element of the present invention was produced by the multi-chamber separation type deposition apparatus shown in FIG. 4-3. In the figure, 1201 and 1212 are load and unload chambers, 12
02, 1203, 1205 to 1209 and 1211 are deposition chambers for each layer by the RF plasma CVD method similar to that in Example 19, 1204 and 1210 are deposition chambers for each layer by the microwave plasma CVD method similar to Example 1, 1221 to
1231 is a gate valve for separating the chambers, 1241 and 12
42, 1244 to 1248 and 1250 are cathode electrodes, and 1243 and 1249 are microwave waveguides and dielectric windows.

First, the substrate is set in the load chamber 1201 and
After the inside of the load chamber 1201 is evacuated, the gate valve 1221 is opened to load the substrate into the first n-type layer deposition chamber 1202.
And the gate valve 1221 was closed. Then, the first n-type layer was formed on the substrate under the same conditions as in the first n-type layer of Example 20.
A mold layer was prepared. The gate valve 1222 is opened, and the substrate is placed in the i-type layer deposition chamber 12 by the first RF plasma CVD method.
03, and closed the gate valve 1222. Then, i according to the first RF plasma CVD method of Example 20
Under the same conditions as the mold layer 1, the i-type layer 1 was formed on the first n-type layer by the first RF plasma CVD method. The gate valve 1223 is opened and the substrate is exposed to the first microwave plasma C
After moving to the i-type layer deposition chamber 1204 by the VD method, the gate valve 1223 was closed. Then, under the same conditions as the i-type layer formed by the first microwave plasma CVD method of Example 20,
An i-type layer formed by the first microwave plasma CVD method was formed on the i-type layer 1 formed by the first RF plasma CVD method.
Further, the gate valve 1224 is opened to set the substrate to the first R
After moving to the i-type layer deposition chamber 1205 by the F plasma CVD method and closing the gate valve 1224, the first microwave plasma CVD method was performed under the same conditions as the i-type layer 2 by the first RF plasma CVD method of Example 20. On the i-type layer by
Then, the i-type layer 2 was formed by the RF plasma CVD method.

[0266] The gate valve 1225 was opened, the substrate was moved to the deposition chamber 1206 for the first p-type doping layer B1, and the gate valve 1225 was closed. First of Example 20
The first p-type layer doping layer B1 was formed on the i-type layer 2 by the first RF plasma CVD method under the same conditions as the p-type layer doping layer B1. Next, the gate valve 1226 is opened, the substrate is moved to the deposition chamber 1207 for doping layer A of the first p-type layer, the gate valve 1226 is closed, and then the first p-type layer doping layer of Example 20 is closed. Under the same conditions as for A, the first p-type layer doping layer A was formed on the first p-type layer doping layer B1. Further, the gate valve 1227
Was opened, the substrate was moved to the first p-type layer doping layer B2 deposition chamber 1208, and the gate valve 1227 was closed. The first p-type layer doping layer B2 was formed on the first p-type layer doping layer A under the same conditions as the first p-type layer doping layer B2 of Example 20.

The gate valve 1228 is opened and the substrate is moved to the second n-type layer deposition chamber 1209.
28 was closed. Then, a second n-type layer was formed on the first p-type layer doping layer B2 under the same conditions as those for the second n-type layer of Example 20.
A mold layer was prepared. The gate valve 1229 was opened, the substrate was moved to the second i-type layer deposition chamber 1210, and the gate valve 1229 was closed. A second i-type layer was formed on the second n-type layer under the same conditions as for the second i-type layer in Example 20. Next, the gate valve 1230 is opened, the substrate is moved to the second p-type layer deposition chamber 1211, the gate valve 1230 is closed, and the second i-type is formed under the same conditions as those for the second p-type layer of Example 20.
A second p-type layer was formed on the mold layer.

The gate valve 1231 was opened, the substrate was moved to the unload chamber 1212, the gate valve 1231 was closed, the substrate was taken out of the unload chamber 1212, and a photovoltaic element was manufactured (element No. 22).

The produced photovoltaic element (element No. 22)
In the same manner as in Example 1, the initial characteristics, the low illuminance characteristics, and the durability characteristics were measured. As a result of the measurement, Example 20 (element N
In the photovoltaic element of Example 22 (element No. 22), the open circuit voltage of the initial characteristics is 1.01 times, the fill factor is 1.02 times, and the low illuminance is higher than that of the photovoltaic element of Example 20). The photoelectric conversion efficiency of the characteristic is 1.03 times, and the photoelectric conversion efficiency of the durability characteristic is 1.02 times excellent. By manufacturing the photovoltaic element of the present invention with the multi-chamber separation type deposition apparatus, it is excellent. It was found that a photovoltaic device having characteristics was obtained, and the effect of the present invention was verified.

(Example 23) A photovoltaic element was produced under the same production conditions as in Example 20, and a solar cell module was produced using the photovoltaic element. In-vehicle ventilation having a circuit configuration as shown in Fig. 9-2 was prepared. Made a fan. In FIG. 9-2, the electric power generated in the solar cell module 9101 attached to the hood of the automobile passes through the backflow prevention diode 9102,
The secondary battery 9104 is charged. Reference numeral 9103 is an overcharge prevention diode. Electric power from the solar cell module 9101 and the secondary battery 9104 is supplied to the motor 9105 of the ventilation fan.

(Comparative Example 6) Under the same manufacturing conditions as in Comparative Example 4,
A photovoltaic element was produced, and using this, an in-vehicle ventilation fan similar to that in Example 20 was produced.

The automobile equipped with the on-vehicle ventilation fan manufactured in Example 23 and Comparative Example 6 was left for 168 hours in an idling state in which the engine was rotated, and then the engine was stopped in fine weather to operate the ventilation fan. It was left to stand and the temperature inside the automobile was measured. As a result, as compared with the vehicle-mounted cooling fan of Comparative Example 6, the vehicle-mounted cooling fan of Example 23 was
The indoor temperature was 3 degrees lower, demonstrating the effect of the power generation system according to the present invention.

(Embodiment 24) From the source gas supply apparatus 1020 and the deposition apparatus 1100 shown in FIG. 4-2 and the production apparatus by the microwave plasma CVD method including the source gas supply apparatus 1020 and the deposition apparatus 1000 shown in FIG. Become R
A photovoltaic device containing P atoms and B atoms in the i-type layer was manufactured by the microwave plasma CVD method using the manufacturing apparatus by the F plasma CVD method.

After the preparation for film formation was completed in the same manner as in Example 1, the n-type layer, the i-type layer and the p-type layer were formed on the substrate by the RF plasma CVD method and the microwave plasma CVD method. It was

To form the n-type layer, the substrate 1004 is heated to 350 ° C. by the heater 1005, the outflow valves 1041 and 1044 and the auxiliary valve 1008 are gradually opened, and SiH ₄ gas and PH ₃ (1%) are added. / H ₂ gas was caused to flow into the deposition chamber 1001 through the gas introduction pipe 1003. At this time, the SiH ₄ gas flow rate is 50 sccm, PH
The mass flow controllers 1021 and 1024 were adjusted so that the flow rate of ₃ (1%) / H ₂ gas was 200 sccm. The pressure in the deposition chamber 1001 is 10 mTorr
The opening of the conductance valve 1007 was adjusted while observing the vacuum gauge 1006 so that

After that, the shutter 1013 is closed, the direct current (DC) bias of the bias power supply 1011 is set to 50 V, and the bias is applied to the bias rod 1012. Then, the power of a microwave power supply (not shown) is set to 130 mW / cm ^3. , A waveguide, a waveguide portion 1010, and a dielectric window 10 (not shown).
Microwave power is introduced into the deposition chamber 1001 through 02 to generate microwave glow discharge, and the shutter 10
After opening 13, an n-type layer was started to be formed on the substrate 1004, and an n-type layer having a layer thickness of 10 nm was formed. After that, the shutter 1013 was closed to stop the microwave glow discharge, the outflow valves 1041 and 1044 and the auxiliary valve 1008 were closed to stop the gas inflow into the deposition chamber 1001, and the n-type layer production was completed.

Next, the substrate 1004 was taken out of the deposition chamber 1001 and placed in the deposition chamber 1101 of the deposition apparatus 1100 by the RF plasma CVD method shown in FIG. 4-2 to form an i-type layer by the RF plasma CVD method.

To form the i-type layer by the RF plasma CVD method, the substrate 1104 is heated to 350 ° C. by the heater 1105 and the outflow valves 1041, 1042, 1 are used.
047, 1048 and the auxiliary valve 1108 are gradually opened, and SiH ₄ gas, H ₂ gas, BF ₃ / H ₂ gas, PH
₃ (2000 ppm) / H ₂ gas was caused to flow into the deposition chamber 1101 through the gas introduction pipe 1103. At this time, SiH
₄ gas flow rate is 8 sccm, H ₂ gas flow rate is 100 sccc
m, BF ₃ / H ₂ gas flow rate is 0.04 sccm, PH
₃ (2000 ppm) / H ₂ gas flow rate of 1 sccm so that each mass flow controller 1021, 10
22, 1027, 1028. Deposition chamber 1101
The pressure inside the vacuum gauge 110 should be 0.5 Torr.
While watching 6, the opening of the conductance valve 1107 was adjusted.

After that, the power of the RF power supply 1111 is set to 120.
RF matching box 111 set to mW / cm ^2.
RF power is introduced to the cathode 1102 through the RF
RF plasma CVD on n-type layer by generating glow discharge
The formation of the i-type layer by the method is started, the RF glow discharge is stopped when the i-type layer having a layer thickness of 10 nm is formed, the outflow valves 1041, 1042, 1047 and 1048 and the auxiliary valve 1108 are closed, and the inside of the deposition chamber 1101 is entered. The gas inflow was stopped and the formation of the i-type layer by the RF plasma CVD method was completed.

Next, the substrate 1104 was taken out of the deposition chamber 1101 and placed in the deposition chamber 1001 of the deposition apparatus 1000 by the microwave plasma CVD method shown in FIG. 4A to form an i-type layer by the microwave plasma CVD method. To produce an i-type layer by the microwave plasma CVD method,
The substrate 1004 is heated to 350 ° C. by the heater 1005, and the outflow valves 1041, 1042, 1046-1
048 and the auxiliary valve 1008 are gradually opened, and SiH
₄ gas, H ₂ gas, GeH ₄ gas, BF ₃ / H ₂ gas, PH ₃
(2000 ppm) / H ₂ gas was caused to flow into the deposition chamber 1001 through the gas introduction pipe 1003. At this time, SiH
₄ gas flow rate is 200sccm, H ₂ gas flow rate is 500sc
cm, GeH ₄ gas flow rate is 1 sccm, BF ₃ / H ₂ gas flow rate is 0.2 sccm, PH ₃ (2000 ppm) / H ₂
Mass flow controllers 1021, 1022, 1026 to 10 so that the gas flow rate is 0.1 sccm.
Adjusted at 28. The opening of the conductance valve 1007 was adjusted while observing the vacuum gauge 1006 so that the pressure in the deposition chamber 1001 became the value shown in Table 20.

Next, the shutter 1013 is closed, the power of the microwave power source (not shown) is set to 170 mW / cm ³ , and the waveguide, the waveguide portion 1010 and the dielectric window 10 (not shown) are set.
The microwave power is introduced into the deposition chamber 1001 through 02 to generate microwave glow discharge, and the bias power source 1
011 radio frequency (RF) bias at 350 mW / cm ³
, DC bias is 0V through the coil for RF cut
And applied to the bias rod 1012.
After that, the shutter 1013 is opened and RF plasma C
The production of the i-type layer by the microwave plasma CVD method was started on the i-type layer by the VD method, and at the same time, the SiH ₄ gas flow rate and the GeH ₄ gas flow rate were changed according to the flow rate pattern shown in FIG. 102
6 to prepare an i-type layer having a layer thickness of 300 nm, the shutter 1013 is closed and the bias power supply 1011
, The microwave glow discharge was stopped, the outflow valves 1041, 1042, 1046 to 1048 and the auxiliary valve 1008 were closed to stop the gas inflow into the deposition chamber 1001.

Next, a p-type layer in which the doping layer A and the doping layer B were laminated was prepared.

To prepare the doped layer B1, the substrate 1
004 is heated to 300 ° C. by the heater 1005, the outflow valves 1041, 1042, 1047 and the auxiliary valve 1008 are gradually opened to deposit SiH ₄ gas, H ₂ gas, and BF ₃ / H ₂ gas through the gas introduction pipe 1003. It was made to flow into the chamber 1001. At this time, the SiH ₄ gas flow rate was 1 sccm, the H ₂ gas flow rate was 300 sccm, and BF ₃ /
The mass flow controllers 1021, 1022, and 1027 were adjusted so that the H ₂ gas flow rate was ₂ sccm. The opening of the conductance valve 1007 was adjusted while observing the vacuum gauge 1006 so that the pressure in the deposition chamber 1001 was 25 mTorr.

Thereafter, the electric power of the microwave power source (not shown) is set to 50 mW / cm ³ , and the waveguide and the waveguide section 1 (not shown) are set.
Microwave power is introduced into the deposition chamber 1001 through 010 and the dielectric window 1002 to generate microwave glow discharge, the shutter 1013 is opened, and the production of the doping layer B1 on the i-type layer by the microwave plasma CVD method is started. Then, when the doping layer B1 having a layer thickness of 0.5 nm is produced, the shutter 1013 is closed to stop the microwave glow discharge, and the outflow valves 1041, 1042, and 1047.
The auxiliary valve 1008 was closed to stop the gas flow into the deposition chamber 1001.

Next, in order to form the doping layer A, the substrate 1004 is heated to 300 ° C. by the heater 1005, the outflow valve 1043 and the auxiliary valve 1008 are gradually opened, and B ₂ H ₆ / H ₂ gas is added. The gas was introduced into the deposition chamber 1001 through the gas introduction pipe 1003. At this time, B ₂ H ₆
/ H ₂ gas flow rate was adjusted to 100 sccm by the mass flow controller 1023. Deposition chamber 1001
The internal pressure is 30 mTorr and the vacuum gauge 100
While watching 6, the opening of the conductance valve 1007 was adjusted.

Thereafter, the power of the microwave power source (not shown) is set to 50 mW / cm ³ , and the waveguide and the waveguide section 1 (not shown) are set.
Microwave power is introduced into the deposition chamber 1001 through 010 and the dielectric window 1002 to generate microwave glow discharge, the shutter 1013 is opened, and the doping layer B1 is formed.
When the fabrication of the doping layer A is started and the doping layer A having a layer thickness of 0.3 nm is produced, the shutter 1013 is formed.
To close the microwave glow discharge and shut off the outflow valve 10.
43 and the auxiliary valve 1008 are closed, and the deposition chamber 1001
The gas inflow was stopped.

Next, except that the layer thickness is 10 nm, the doping layer A is produced under the same manufacturing conditions as the above-mentioned doping layer B1.
A doping layer B2 was formed on top. When producing each layer, outflow valves 1041-10 other than required gas
Needless to say, 49 is completely closed, and the gas in each of the deposition chambers 1001 and 1101,
In order to avoid remaining in the pipes from the outflow valves 1041 to 1049 to the deposition chambers 1001 and 1101,
The outflow valves 1041 to 1049 are closed, and the auxiliary valve 10
08 and 1108 are opened, the conductance valves 1007 and 1107 are fully opened, and the system is temporarily evacuated to a high vacuum, if necessary.

Next, as a transparent electrode, IT was formed on the p-type layer.
A 0 (In ₂ 0 ₃ + SnO ₂ ) thin film having a thickness of 70 nm and an aluminum (Al) thin film having a thickness of 2 μm as a collector electrode were vacuum-deposited to manufacture a photovoltaic element (element No. 241-2.
7, ratio 7-1).

Table 19 shows the manufacturing conditions of the photovoltaic element described above.
Shown in. The initial characteristics, low illuminance characteristics, and durability characteristics of the photovoltaic elements produced in Example 24 (element No. Ex. 24-1 to 7) and Comparative Example 7 (element No. ratio 7-1) were measured. Table 20 shows the measurement results.

As can be seen from Table 20, the pressure inside the deposition chamber 1001 is 5 when the i-type layer formed by the microwave plasma CVD method is used.
It has been found that a photovoltaic device having excellent characteristics can be obtained by manufacturing the device at 0 mTorr or less.

Next, using a barium borosilicate glass (7059 manufactured by Corning Corporation) substrate, SiH ₄ gas flow rate, G
Except that the eH ₄ gas flow rate and the power of the microwave power source were set to the values shown in Table 3, the shutter 1013 was kept for 2 minutes under the same manufacturing conditions as the i-type layer by the microwave plasma CVD method of the element No. 24-5 described above. After opening, an i-type layer was formed on the substrate by the microwave plasma CVD method to prepare a sample for measuring the raw material gas decomposition efficiency, and the decomposition efficiency of the raw material gas was determined from the layer thickness, and the same result as in Table 3 was obtained. .

Next, when the i-type layer is formed by the microwave plasma CVD method, the power of the microwave power source is shown in Table 21.
Under the same manufacturing conditions as those of the photovoltaic element of Element No. 24-5 described above, except for the values shown in, a reflective layer, a transparent conductive layer, an n-type layer, an i-type layer, a p-type layer, A transparent electrode and a current collecting electrode were produced to produce a photovoltaic element (element No. 24-
8-10 and ratios 7-2-3).

The manufactured photovoltaic element (element No. 24-24)
8 to 10 and the ratio 7-2 to 3) are the above-mentioned element No.
Initial characteristics, low illuminance characteristics, and durability characteristics were measured by the same method as in the photovoltaic device of Example 5. Table 21 shows the measurement results. As can be seen from Table 21, it was found that by decomposing the raw material gas with microwave energy lower than the microwave energy required to decompose 100% of the raw material gas, a photovoltaic element having excellent characteristics can be obtained.

Next, when the i-type layer was formed by the microwave plasma CVD method, the same production as that of the above-mentioned element No. 24-5, except that the RF bias was set to the value shown in Table 22, was produced. Under the conditions, on the substrate, a reflective layer, a transparent conductive layer,
An n-type layer, an i-type layer, a p-type layer, a transparent electrode, and a collector electrode were produced to produce a photovoltaic element (Element No. Ex. 24-11 to 1).
4 and ratio 7-4).

The produced photovoltaic element (element No. 24-
11 to 14 and the ratio 7-4) were measured for initial characteristics, low illuminance characteristics and durability characteristics in the same manner as in the above photovoltaic device. The measurement results are shown in Table 22. As you can see from Table 22,
It has been revealed that a photovoltaic element having excellent characteristics can be obtained by causing the source gas to have RF energy higher than microwave energy.

Then, a sample for measuring physical properties was prepared in the same manner as in Example 1. Here, microwave plasma CVD
I-type layer by law, SiH4 _gas flow rate and GeH ₄ gas flow rate, except that the values shown in Table 6, above element No real 2
The production conditions of the i-type layer by the microwave plasma CVD method of 4-5 were followed.

The bandgap and composition of the produced sample for measuring physical properties were analyzed, and the relationship between the composition ratio of Si atoms and Ge atoms and the bandgap was determined. The same results as in Table 6 were obtained.

Next, when the i-type layer is formed by the microwave plasma CVD method, the SiH ₄ gas flow rate and the GeH ₄ gas flow rate are set by the mass flow controllers 1021 and 1026 according to the flow rate pattern shown in FIG. 5 (2). A reflective layer, a transparent conductive layer, an n-type layer, an i-type layer, a p-type layer, a transparent electrode, and a current collecting electrode were produced on a substrate under the same production conditions as those of the above-mentioned Element No. 24-5 except that the adjustment was performed. Then, a photovoltaic element was manufactured (element No. ratio 7-5).

The initial characteristics, the low illuminance characteristics and the durability characteristics of the produced photovoltaic element having the element No. ratio 7-5 were measured by the same method as that of the element No. Ex. 24-5. Measurement result, element No.
Element No. 24-5 for the photovoltaic element with the ratio 7-5
In the photovoltaic element of, the open circuit voltage of the initial characteristics is 1.02 times,
The fill factor is 1.03 times, the photoelectric conversion efficiency of low illumination characteristics is 1.09 times, and the photoelectric conversion efficiency of durability characteristics is 1.07.
Was twice as good.

Next, the composition analysis in the layer thickness direction of Si atoms and Ge atoms in the i-type layer of the photovoltaic elements of the element No. real 24-5 and the element No. ratio 7-5 by the microwave plasma CVD method was conducted as described above. It carried out by the method similar to composition analysis. Then, FIG. 6 shows the result of obtaining the change in the band gap in the layer thickness direction of the i-type layer by the microwave plasma CVD method from the relationship between the composition ratio and the band gap described above. As can be seen from FIG. 6, in the photovoltaic element of Element No. 24-5, the position of the minimum bandgap is from the center position of the i-type layer to the interface between the p-type layer and the i-type layer formed by the microwave plasma CVD method. In the photovoltaic device with the device No. ratio 7-5, which is offset in the direction, the position of the minimum value of the band gap is R from the position of the center of the i-type layer formed by the microwave plasma CVD method.
It can be seen that the i-type layer formed by the F plasma CVD method and the i-type layer formed by the microwave plasma CVD method are offset in the interface direction.

Next, when producing an i-type layer by the microwave plasma CVD method, BF ₃ / H ₂ and PH ₃ (200
0ppm) / H ₂ is not used, and the above element No. 24
Under the same conditions as in -5, a reflective layer, a transparent conductive layer, an n-type layer, an i-type layer, a p-type layer, a transparent electrode, and a collector electrode are formed on a substrate, and a photovoltaic element (element No. 24-5) is formed. ') Was made.

The initial characteristics, the low illuminance characteristics, and the durability characteristics of the produced photovoltaic element No. Ex 24-5 ′ were measured by the same method as that of Element No. Ex 24-5. As a result of the measurement,
For the photovoltaic element of element No. 24-5 ′, the element N
o The real 24-5 photovoltaic element has an open circuit voltage of initial characteristics of 1.02, a fill factor of 1.03 times, a photoelectric conversion efficiency of low illuminance characteristics of 1.09 times, and a photoelectric conversion efficiency of durability characteristics of The decrease was 1.08 times better.

Table 23 shows the SiH ₄ gas flow rate and the RF discharge power when the i-type layer was formed by the RF plasma CVD method.
Under the same manufacturing conditions as in Element No. 24-5 except for the value of, a reflective layer, a transparent conductive layer, an n-type layer, an i-type layer,
A p-type layer, a transparent electrode, and a collector electrode were prepared to prepare a photovoltaic element. (Element No. Ex. 24-15 to 19, Element No. 7-6) Produced photovoltaic element (Element No. Ex. 24-15)
.About.19, element No. ratio 7-6), the initial characteristics, the low illuminance characteristics and the durability characteristics were measured by the same method as the element No. Ex. 24-5. The results are shown in Table 23.

At the same time, a sample for measuring the deposition rate was prepared, and the deposition rate was obtained from the film thickness and the deposition time. The results are shown in Table 23.

As can be seen from Table 23, RF plasma CVD
It was found that a photovoltaic element having excellent characteristics can be obtained by producing the i-type layer by the method at a deposition rate of 2 nm / sec or less.

When the i-type layer was formed by the RF plasma CVD method, except that the layer thickness of the i-type layer was set to the value shown in Table 24, the same production condition as that of the element No. 24-5 was used to form the i-type layer on the substrate. ,
A photovoltaic element was manufactured by manufacturing a reflective layer, a transparent conductive layer, an n-type layer, an i-type layer, a p-type layer, a transparent electrode, and a collector electrode (element No. 24-20 to 22, element No. ratio 7). -7-8).

[0307] The manufactured photovoltaic element (element No. 24-
20-22, element No. ratio 7-7-8), and element No. 24
Initial characteristics, low illuminance characteristics and durability characteristics were measured by the same method as in -5. The results are shown in Table 24.

As can be seen from Table 24, the layer thickness of the present invention is 3
It has been found that the photovoltaic element (element No. 24-20 to 22) having an i-type layer formed by the RF plasma CVD method of 0 nm or less has excellent characteristics.

Next, when the i-type layer was formed by the RF plasma CVD method, on the substrate under the same manufacturing conditions as in Element No. 24-5 except that the RF discharge power was set to the value shown in Table 25. Then, a reflective layer, a transparent conductive layer, an n-type layer, an i-type layer, a p-type layer, a transparent electrode, and a collector electrode were produced to produce photovoltaic devices (Element Nos. 24-23 to 26).

The produced photovoltaic element (element No. 24-24)
23 to 26), the initial characteristics, the low illuminance characteristics, and the durability characteristics were measured by the same method as in Element No. 24-5. The results are shown in Table 25.

At the same time, a sample for infrared spectroscopic measurement was prepared, and the value obtained by dividing the half-width by the height at the peak of 2000 cm ^{-1 in} the infrared absorption spectrum was determined. The results are shown in Table 25. Each value is a relative value based on the value of a sample manufactured under the same conditions as the i-type layer of the element No. Ex 24-5 by the microwave plasma CVD method.

As can be seen from Table 25, the value obtained by dividing the full width at half maximum by the height at the peak of 2000 cm ^{−1 in} the infrared absorption spectrum is higher than that of the i-type layer formed by the microwave plasma CVD method and the i-type formed by the RF plasma CVD method. It has been found that photovoltaic devices with larger layers have excellent properties.

Next, when forming the p-type layer, except that the doping layer A was not formed and only the doping layer B was used, the same manufacturing conditions as those of the element No. 24-5 described above were used to form a p-type layer on the substrate.
A photovoltaic element was manufactured by manufacturing a reflective layer, a transparent conductive layer, an n-type layer, an i-type layer, a p-type layer, a transparent electrode, and a collector electrode (element No. ratio 7-9).

The initial characteristics, the low illuminance characteristics and the durability characteristics of the manufactured photovoltaic element having the element No. ratio 7-9 were measured by the same method as that of the element No. Ex. 24-5. Measurement result, element N
o For the photovoltaic element with the ratio 7-9, the element No.
The photovoltaic element of 5 has an open circuit voltage of 1.04 as an initial characteristic,
The fill factor is 1.02 times, the photoelectric conversion efficiency of the low illuminance characteristic is 1.10 times, and the photoelectric conversion efficiency of the durability characteristic is 1.07.
Was twice as good.

From the above measurement results, the internal pressure of the i-type layer formed by the microwave plasma CVD method of the present invention was 50 mTorr.
Below, the microwave energy lower than the microwave energy required to decompose 100% of the source gas, the RF energy acting on the source gas is higher than the microwave energy, the band gab changes smoothly in the layer thickness direction, The position of the minimum value of the band gap is offset from the center position of the i-type layer toward the interface between the p-type layer and the i-type layer, and the valence electron control agent serving as a donor and an acceptor is doped in the i-type layer, and RF I by plasma CVD method
The type layer has a layer thickness of 30 nm or less at a deposition rate of 2 nm / sec or less, and at least one of the p-type layer and the n-type layer contains a group III element or / and a group V element of the periodic table as a main constituent element. Photovoltaic device manufactured with a laminated structure of a layer and a layer containing a valence electron control agent and having silicon atoms as a main constituent element (element No.
Examples 24-1 to 26) are conventional photovoltaic elements (element No.
It was found that the ratio of 7-1 to 9) was excellent, and the effect of the present invention was proved.

(Example 25) Microwave plasma CVD
Flow rate of SiH ₄ gas and G
The eH ₄ gas flow rate was set according to the flow rate pattern shown in FIG.
21, after adjusting with 1026, SiH ₄ gas flow rate 2
Example No. 2 of Example 24 except that the film thickness was set to 00 sccm, the GeH ₄ gas flow rate was maintained at 1 sccm, and the band gap maximum value region was set to have the layer thickness shown in Table 26.
Under the same manufacturing conditions as in 4-5, a reflective layer, a transparent conductive layer, an n-type layer, an i-type layer, a p-type layer, a transparent electrode, and a collector electrode were formed on a substrate to prepare a photovoltaic element ( Element No. real 25-1
8).

The manufactured photovoltaic element (element No. 25-
1 to 8) were measured for initial characteristics, low illuminance characteristics and durability characteristics in the same manner as in Example 24. The results are shown in Table 26. As can be seen from Table 26, it was found that the photovoltaic element (element No. Ex. 25-1 to 7) having a layer thickness of 1 to 30 nm in the bandgap maximum value region of the present invention has excellent characteristics. The effect of the invention was proved.

(Example 26) Microwave CVD method and R
When the i-type layer is formed by the F plasma CVD method, the PH
₃ (2000ppm) / H ₂ in place of the gas cylinder diluted to 2000ppm by H ₂ gas AsH ₃ gas (AsH ₃ /
H ₂₎ using a cylinder, 0.2 sccm of AsH ₃ / H ₂ gas in the i-type layer by microwave plasma CVD method, RF
In the i-type layer formed by the plasma CVD method, a reflective layer, a transparent conductive layer, an n-type layer, and an i-type layer were formed on the substrate under the same production conditions as in Example 24-5 except that AsH ₃ / H ₂ gas was flowed at 0.5 sccm. A layer, a p-type layer, a transparent electrode, and a collector electrode were produced to produce a photovoltaic element (element No. 26).

The photovoltaic element manufactured in Example 26 (element No. 26) was subjected to the same procedure as in Example 24 to obtain the initial characteristics,
When the low illuminance property and the durability property were measured, Example 24
Element No. 24-5, the same initial characteristics, low illuminance characteristics,
Durability was obtained, and the effect of the present invention was verified.

(Example 27) Microwave plasma CVD
When the i-type layer is produced by the method, the BF ₃ / H ₂ gas flow rate is set to PH ₃ (2000 p) by the flow rate pattern shown in FIG.
pm) / H ₂ gas flow rate is adjusted according to the flow rate pattern shown in FIG. 14 (2) by mass flow controllers 1027 and 1028, respectively, and BF ₃ / H ₂ gas is used when an i-type layer is formed by the RF plasma CVD method. Flow rate 0.06s
ccm, PH ₃ (2000ppm) / H ₂ gas flow rate for 2s
The reflective layer, the transparent conductive layer, the n-type layer, the i-type layer, the p-type layer, the transparent electrode, and the current collecting electrode were formed on the substrate under the same manufacturing conditions as in Element No. 24-5 of Example 24 except that the flow rate was changed to ccm. To produce a photovoltaic element (Element No. Ex 27).

The photovoltaic element manufactured in Example 27 (element No. 27) was subjected to the same procedure as in Example 24 to obtain the initial characteristics,
When the low illuminance property and the durability property were measured, Example 24
Element No. 24-5, the same initial characteristics, low illuminance characteristics,
Durability characteristics were obtained.

FIG. 14 shows the result of analysis by a secondary ion mass spectrometer of the distribution of B atoms and P atoms in the i-type layer in the photovoltaic element of Example 27 (element No. 27) in the layer thickness direction. It shows in (3) and (4). From the above results, the effect of the present invention was verified.

(Example 28) Microwave plasma CVD
NO / He gas cylinder 1079 is used when an i-type layer is formed by the RF method and the RF plasma CVD method.
Except that the gas flow rate was 0.5 sccm for the i-type layer formed by the microwave plasma CVD method and 0.05 sccm for the i-type layer formed by the RF plasma CVD method, the production conditions were the same as those for the element No. 24-5 of Example 24. On the substrate, the reflective layer,
A transparent conductive layer, an n-type layer, an i-type layer, a p-type layer, a transparent electrode, and a collector electrode were produced to produce a photovoltaic element (element No. 2).
8).

The manufactured photovoltaic element (element No. 28)
In the same manner as in Example 24, the initial characteristics, the low illuminance characteristics, and the durability characteristics were measured. As a result, the same initial characteristics, low illuminance characteristics, and durability characteristics as those of Element No. 24-5 of Example 24 were obtained. .

Composition analysis of the photovoltaic element of Example 28 (Element No. 28) by a secondary ion mass spectrometer revealed that the i-type layer contained oxygen atoms and nitrogen atoms. confirmed. From the above results, the effect of the present invention was verified.

(Example 29) Microwave plasma CVD
When forming the i-type layer by the method, a Si ₂ H ₆ gas cylinder (not shown) is used, the Si ₂ H ₆ gas flow rate is set to 40 sccm,
A reflective layer and a transparent conductive layer were formed on the substrate under the same manufacturing conditions as the element No. 24-5 of Example 24, except that the SiH ₄ gas flow rate was adjusted by the mass flow controller 1021 according to the flow rate pattern shown in FIG. 7 (1). , N-type layer, i-type layer,
A p-type layer, a transparent electrode, and a collector electrode were formed to fabricate a photovoltaic element (element No. 29).

The manufactured photovoltaic element (element No. 29)
In the same manner as in Example 24, the initial characteristics, the low illuminance characteristics, and the durability characteristics were measured. As a result, the same initial characteristics, low illuminance characteristics, and durability characteristics as those of Element No. 24-5 of Example 24 were obtained. .

The distribution of Si atoms and hydrogen atoms in the photovoltaic element of Example 29 (element No. 29) in the layer thickness direction in the i-type layer was analyzed by a secondary ion mass spectrometer. Results similar to 7 (2) were obtained.

From the above results, the effect of the present invention was verified.

(Embodiment 30) Source gas supply apparatus 1020
In the same manufacturing conditions as the element No. 24-5 of Example 24, except that the distance between the deposition chamber 1001 and the point 1014 at which the SiH ₄ gas and GeH ₄ gas are mixed is set to the value shown in Table 11. On the substrate, a reflective layer, a transparent conductive layer, an n-type layer, an i-type layer, a p-type layer, a transparent electrode, and a current-collecting electrode were produced to produce a photovoltaic element (element No. 30-1 to 5). .

The manufactured photovoltaic element (element No. 30-
1 to 5) were measured in the same manner as in Example 24 to measure initial characteristics, low illuminance characteristics and durability characteristics. The measurement results are shown in Table 27. As can be seen from Table 27, it was found that by setting the distance between the point 1014 where SiH ₄ gas and GeH ₄ gas are mixed and the deposition chamber 1001 to be 5 m or less, a photovoltaic element having good characteristics can be obtained. .

(Example 31) Element No. 2 of Example 24
A photovoltaic element was produced under the same production conditions as 4-5, a solar cell module was produced using this, and an analog timepiece having a circuit configuration as shown in FIG. 9-2 was produced. In FIG. 9-2, the electric power generated in the solar cell module 9101 is passed through the backflow prevention diode 9102, and the secondary battery 91
It is charged to 04. Reference numeral 9103 is an overcharge prevention diode.

Electric power from the solar cell module 9101 and the secondary battery 9104 is supplied to the drive circuit 910 of the analog timepiece.
5 is supplied.

(Comparative Example 8) Element No. ratio 7-6 of Comparative Example 7
A photovoltaic element was produced under the same production conditions as above, and using this, an analog timepiece similar to that of Example 31 was produced.

When the analog timepieces produced in Example 31 and Comparative Example 8 were installed on the wall in the room and the interior light was turned on for 8.5 hours every day, the analog timepiece of Example 31 ran all day, but Comparative Example 8 The analog timepiece of No.1 did not move all day, demonstrating the effect of the power generation system according to the present invention.

(Example 32) Microwave plasma CVD
Element No. 24-5 of Example 24 except that the SiH ₄ gas flow rate and the GeH ₄ gas flow rate were adjusted by the mass flow controllers 1021 and 1026 in accordance with the flow rate pattern shown in FIG. Under the same production conditions, a reflective layer, a transparent conductive layer, an n-type layer, an i-type layer, a p-type layer, a transparent electrode, and a collector electrode were produced on the substrate to produce a photovoltaic element (Element No. 32). ).

The manufactured photovoltaic element (element No. 32)
When the initial characteristics, the low illuminance characteristics and the durability characteristics were measured by the same method as in Example 24, the same initial characteristics, low illuminance characteristics and durability characteristics as the element No. 24-5 of Example 24 were obtained, The effect of the present invention was demonstrated.

(Example 33) Microwave plasma CVD
Act and in making the i-type layer by RF plasma CVD method, in place of the BF ₃ / H ₂ gas cylinder with H ₂ gas 2000
B ₂ H ₆ gas diluted to ppm (B ₂ H ₆ (2000 pp
m) / H ₂ ) cylinder using microwave plasma CVD
1 sccm of B ₂ H ₆ (2000 ppm) / H ₂ gas in the i-type layer formed by the method, and 0.05 sc of B ₂ H ₆ (2000 ppm) / H ₂ gas in the i-type layer formed by the RF plasma CVD method.
under the same manufacturing conditions as in Element No. 24-5 of Example 24, except that the flow rate is cm. To produce a photovoltaic element (element No. 33).

The manufactured photovoltaic element (element No. 33)
When the initial characteristics, the low illuminance characteristics and the durability characteristics were measured by the same method as in Example 24, the same initial characteristics, low illuminance characteristics and durability characteristics as the element No. 24-5 of Example 24 were obtained, The effect of the present invention was demonstrated.

(Example 34) Microwave plasma CVD
When producing an i-type layer by the method, NO / He gas is used as shown in FIG.
0 (1) according to the flow rate pattern, except that the mass flow controller 1029 was used, under the same manufacturing conditions as the element No. 24-5 of Example 24, the reflective layer, the transparent conductive layer, the n-type layer, on the substrate, i-type layer, p-type layer, transparent electrode,
A collector electrode was prepared and a photovoltaic element was prepared (element No.
34).

Photovoltaic device manufactured (device No. 34)
When the initial characteristics, the low illuminance characteristics and the durability characteristics were measured by the same method as in Example 24, the same initial characteristics, low illuminance characteristics and durability characteristics as those of the element No. 24-5 of Example 24 were obtained. .

The distribution of nitrogen atoms and oxygen atoms in the i-type layer of the photovoltaic element of Example 34 (element No. 34) in the layer thickness direction was analyzed by a secondary ion mass spectrometer. The result was similar to 10 (2). From the above results, the effect of the present invention was verified.

(Example 35) Microwave plasma CVD
When the i-type layer is produced by the method, the SiH ₄ gas flow rate and the GeH ₄ gas flow rate are adjusted by the mass flow controllers 1021 and 1026 according to the flow rate pattern shown in FIG. 11, and the i-type layer is produced by the microwave plasma CVD method. Then, the i-type layer 2 formed by the RF plasma CVD method is shown in Table 1.
Under the same manufacturing conditions as in Example 24 except that the reflective layer, the transparent conductive layer, the n-type layer, and
The i-type layer, the p-type layer, the transparent electrode, and the collector electrode were produced to produce a photovoltaic element (element No. 35).

The produced photovoltaic element (element No. 35)
When the initial characteristics, the low illuminance characteristics and the durability characteristics were measured by the same method as in Example 24, the same initial characteristics, low illuminance characteristics and durability characteristics as the element No. 24-5 of Example 24 were obtained, The effect of the present invention was demonstrated.

(Example 36) Under the same manufacturing conditions as in Element No. 24-5 of Example 24, except that the layer thickness of the doping layer A was changed to the value shown in Table 28 in manufacturing the p-type layer, On the substrate, a reflective layer, a transparent conductive layer, an n-type layer, an i-type layer, a p-type layer,
A transparent electrode and a collector electrode were produced to produce a photovoltaic element (Element No. Ex. 36-1 to 5).

The manufactured photovoltaic element (element No. 36-
1 to 5) were measured for initial characteristics, low illuminance characteristics and durability characteristics in the same manner as in Example 24. The results are shown in Table 28. As can be seen from Table 28, the photovoltaic device (device No.) in which the layer thickness of the doping layer A of the present invention is 0.01 to 1 nm.
It was found that the fruits 36-1 to 5) have excellent characteristics,
The effect of the present invention was demonstrated.

(Example 37) Element No. 24 of Example 24 was manufactured except that the doping layer A and the doping layer B were manufactured under the manufacturing conditions shown in Table 14 when manufacturing the n-type layer.
Under the same manufacturing conditions as in No. 5, a reflective layer, a transparent conductive layer, and
An n-type layer, an i-type layer, a p-type layer, a transparent electrode, and a collector electrode were prepared to prepare a photovoltaic device (Device No. 37).

The manufactured photovoltaic element (element No. 37)
In the same manner as in Example 24, the initial characteristics, the low illuminance characteristics and the durability characteristics were measured, and the same initial characteristics, the low illuminance characteristics and the durability characteristics as in Example 24 were obtained, and the effect of the present invention was verified. It was

Example 38 Element No. 24 of Example 24 was prepared except that the doping layer A and the doping layer B were manufactured under the manufacturing conditions shown in Table 15 when manufacturing the p-type layer.
Under the same manufacturing conditions as in No. 5, a reflective layer, a transparent conductive layer, and
An n-type layer, an i-type layer, a p-type layer, a transparent electrode, and a collector electrode were produced to produce a photovoltaic element (element No. 38).

Photovoltaic device manufactured (device No. 38)
In the same manner as in Example 24, the initial characteristics, the low illuminance characteristics and the durability characteristics were measured, and the same initial characteristics, the low illuminance characteristics and the durability characteristics as in Example 24 were obtained, and the effect of the present invention was verified. It was

(Example 39) Microwave plasma CVD
Bias power supply 1011 when an i-type layer is produced by the method
Example 3 except that the RF bias was set to 250 mW / cm ³ and the DC bias was set to 50 V via a coil for RF cutting and applied to the bias rod 1012.
Under the same manufacturing conditions as in 2, the reflective layer, the transparent conductive layer, and the
An n-type layer, an i-type layer, a p-type layer, a transparent electrode, and a collector electrode were produced to produce a photovoltaic element (Element No. 39).

Photovoltaic device produced (element No. 39)
In the same manner as in Example 32, the initial characteristics, the low illuminance characteristics and the durability characteristics were measured, and the same initial characteristics, the low illuminance characteristics and the durability characteristics as in Example 32 were obtained, and the effect of the present invention was verified. It was

(Example 40) Microwave plasma CVD
In making the i-type layer by law, using D ₂ gas cylinder, not shown, instead of H ₂ gas cylinder, 300Sc the D ₂ gas
under the same manufacturing conditions as in Element No. 24-5 of Example 24 except that the flow of cm is performed, a reflective layer, a transparent conductive layer, an n-type layer, an i-type layer, a p-type layer, a transparent electrode, and a collector electrode are formed on the substrate. To produce a photovoltaic element (element No. 40).

The produced photovoltaic element (element No. 40)
When the initial characteristics, the low illuminance characteristics and the durability characteristics were measured by the same method as in Example 24, the same initial characteristics, low illuminance characteristics and durability characteristics as those of the element No. 24-5 of Example 24 were obtained. .

The manufactured Example 40 (element No. 4)
When the composition of the photovoltaic element of 0) was analyzed by a secondary ion mass spectrometer, it was confirmed that D atom was contained in the i-type layer by the microwave plasma CVD method. From the above results, the effect of the present invention was verified.

(Example 41) When manufacturing the n-type layer, the DC bias of the bias power supply 1011 was set to the shutter 10.
Element No. 24-24 of Example 24 was used except that 13 was opened and at the same time, the voltage was changed from 50 V to 80 V at a constant rate.
Under the same manufacturing conditions as above, a reflective layer, a transparent conductive layer, n
A photovoltaic layer was produced by forming a mold layer, an i-type layer, a p-type layer, a transparent electrode, and a collector electrode (element No. 41).

The produced photovoltaic element (element No. 41)
When the initial characteristics, the low illuminance characteristics and the durability characteristics were measured by the same method as in Example 24, the same initial characteristics, low illuminance characteristics and durability characteristics as the element No. 24-5 of Example 24 were obtained, The effect of the present invention was demonstrated.

(Embodiment 42) The RF of the embodiment 24 is manufactured by using the manufacturing apparatus by the RF plasma CVD method shown in FIG.
The n-type layer and the p-type layer of the photovoltaic element of the present invention were produced by the same procedure as the i-type layer by the plasma CVD method.

To form the n-type layer, the substrate 1104 is heated to 350 ° C. by the heater 1105, and the outflow valves 1042, 1044, 1045 and the auxiliary valve 110 are heated.
8 was gradually opened, and H ₂ gas, PH ₃ (1%) / H ₂ gas, and Si ₂ H ₆ gas were caused to flow into the deposition chamber 1101 through the gas introduction pipe 1103. At this time, the H ₂ gas flow rate is 50
sccm, PH ₃ (1%) / H ₂ gas flow rate is 5 sccm,
The mass flow controllers 1022, 1024, and 1025 were adjusted so that the Si ₂ H ₆ gas flow rate was 3 sccm. The pressure inside the deposition chamber 1101 was adjusted to 1 Torr by adjusting the opening of the conductance valve 1107 while watching the vacuum gauge 1106.

After that, the power of the RF power supply 1111 is set to 120.
RF matching box 1112 with mW / cm ² set
RF power is introduced to the cathode 1102 through the cathode to generate an RF glow discharge, the formation of an n-type layer is started on the substrate 1104, and an n-type layer having a layer thickness of 10 nm is formed.
Stop the glow discharge and spill valves 1042, 1044, 1
045 and the auxiliary valve 1108 are closed and the deposition chamber 110 is closed.
The gas flow into the inside of No. 1 was stopped, and the formation of the n-type layer was completed.

Next, an i-type layer was formed by the RF plasma CVD method on the n-type layer under the same production conditions as those of the element No. 24-5 of Example 24. Next, RF from the deposition chamber 1101
Substrate 1104 having an i-type layer formed by plasma CVD method
Of the microwave plasma C similar to that in Example 24.
The RF plasma CV was installed in the deposition apparatus 1000 by the VD method, and under the same production conditions as the element No. 24-5 of Example 24.
An i-type layer was formed on the i-type layer by the D method by the microwave plasma CVD method.

Next, the substrate 1004 on which the i-type layer was formed by the microwave plasma CVD method was taken out from the deposition chamber 1000, and the deposition apparatus 1 by the RF plasma CVD method described above was taken out.
It is installed at 100 and i by microwave plasma CVD method
A p-type layer was prepared by stacking a doping layer A and a doping layer B on the mold layer.

To prepare the doped layer B, the substrate 11
04 is heated to 200 ° C. by the heater 1105,
Outflow valves 1041, 1042, 1047 and 1108
Was gradually opened, and SiH ₄ gas, H ₂ gas, and BF ₃ / H ₂ gas were caused to flow into the deposition chamber 1101 through the gas introduction pipe 1103. At this time, the SiH ₄ gas flow rate is 0.03 scc
m, H ₂ gas flow rate was 100 sccm, and BF ₃ / H ₂ gas flow rate was 1 sccm. The pressure inside the deposition chamber 1101 was adjusted to 1 Torr by adjusting the opening of the conductance valve 1107 while watching the vacuum gauge 1106.

After that, the power of the RF power supply 1111 is set to 2 W /
cm ² is set, RF power is introduced to the cathode 1102 through the RF matching box 1112, RF glow discharge is generated, and i by microwave plasma CVD method is applied.
Starting the production of the doping layer B1 on the mold layer, the layer thickness 0.3
The RF glow discharge is stopped when the doped layer B1 having a thickness of 10 nm is produced, and the outflow valves 1041, 1042, and 1047 are discharged.
The auxiliary valve 1108 was closed to stop the gas flow into the deposition chamber 1101.

Next, in order to form the doping layer A, the substrate 1104 is heated to 200 ° C. by the heater 1105, the outflow valve 1043 and the auxiliary valve 1108 are gradually opened, and B ₂ H ₆ (10%) / H ₂ gas was caused to flow into the deposition chamber 1101 through the gas introduction pipe 1103. At this time, the mass flow controller 1023 adjusted the B ₂ H ₆ (10%) / H ₂ gas flow rate to be 50 sccm. The opening of the conductance valve 1107 was adjusted while observing the vacuum gauge 1106 so that the pressure in the deposition chamber 1101 was 1 Torr.

After that, the power of the RF power supply 1111 is set to 3 W /
cm ² and RF power is introduced into the cathode 1102 through the RF matching box 1112 to cause RF glow discharge, and the doping layer A is formed on the doping layer B1.
Was started, and when the doping layer A having a layer thickness of 0.1 nm was prepared, the RF glow discharge was stopped and the outflow valve 10
48 and the auxiliary valve 1108 are closed and the deposition chamber 1101
The gas flow to the inside was stopped.

Next, the SiH ₄ gas flow rate is changed to 0.5 sccc.
m, BF ₃ / H ₂ gas flow rate 10 sccm, layer thickness 5 nm
A doping layer B2 was formed on the doping layer A under the same manufacturing conditions as the above-described doping layer B1 except for the above.

Finally, on the p-type layer, the device N of Example 24 was formed.
o A transparent electrode and a collecting electrode were vapor-deposited in the same manner as in Ex. 24-5 to manufacture a photovoltaic element (Element No. Ex. 42-1).

The manufacturing conditions of the photovoltaic element described above are as shown in Table 16 except for the i-type layer. The i-type layer was manufactured under the same conditions as the element No. 24-5 of Example 24.

Further, when the i-type layer is formed by the microwave plasma CVD method, BF ₃ / H ₂ gas and PH ₃ (20
00ppm) / H ₂ gas is used, but element No. 4
Under the same production conditions as in 2-1, a reflective layer, a transparent conductive layer, an n-type layer, an i-type layer, a p-type layer, a transparent electrode, and a collector electrode were produced on a substrate to produce a photovoltaic element ( Element No. 42-
2).

Example 24 (Element No. Ex 42-1 and No. 2-2)
The initial characteristics, the low illuminance characteristics, and the durability characteristics were measured by the same method. As a result of the measurement, the photovoltaic element of element No. 42-1 is
Open-circuit voltage of initial characteristics is 1.04 times, fill factor is 1.03
2 times, the photoelectric conversion efficiency of the low illuminance characteristic was 1.09 times, and the decrease of the photoelectric conversion efficiency of the durability characteristic was 1.07 times excellent, demonstrating the effect of the present invention.

[0372] In the formation of the i-type layer by (Example 43) a first microwave plasma CVD method, flow BF ₃ / H ₂ gas 0.3 sccm, and _{PH 3 (2000ppm) / H 2} 0.5sccm gas Except for the manufacturing conditions shown in Table 17, the reflective layer, the transparent conductive layer, the first n-type layer, the first i-type layer, and the first p-type layer were formed on the substrate by the same method as in Example 24. , A second n-type layer, a second i-type layer, a second p-type layer,
A transparent electrode and a collecting electrode were produced to produce a photovoltaic element (element No. 43).

The photovoltaic element manufactured in Example 43 (element No. 43) was subjected to the same procedure as in Example 24 to obtain the initial characteristics,
The low illuminance property and the durability property were measured.

As a result of the measurement, the photovoltaic element of Example 43 (element No. 43) had an open circuit voltage having an initial characteristic with respect to the photovoltaic element (Element No. 20) manufactured under the conditions of Table 17. 1.03 times, the fill factor is 1.04 times, the photoelectric conversion efficiency of the low illuminance characteristic is 1.09 times, and the decrease of the photoelectric conversion efficiency of the durability characteristic is 1.06 times, showing that further excellent characteristics can be obtained. It was

(Example 44) When forming an i-type layer by the first microwave plasma CVD method, BF ₃ / H ₂ gas 1 was used.
sccm, PH ₃ (2000ppm) / H ₂ gas 0.3
sccm and 0.5 sccm of BF ₃ / H ₂ gas when forming the i-type layer by the second microwave plasma CVD method,
And PH ₃ (2000 ppm) / H ₂ gas at 0.1 sccc
A reflective layer, a transparent conductive layer, a first conductive layer, a transparent conductive layer
N-type layer, first i-type layer, first p-type layer, second n-type layer, second i-type layer, second p-type layer, third n-type layer, third
The i-type layer, the third p-type layer, the transparent electrode, and the current collecting electrode were produced to produce a photovoltaic element (element No. 44).

The photovoltaic element manufactured in Example 44 (element No. 44) was subjected to the same procedure as in Example 24 to obtain the initial characteristics,
The low illuminance property and the durability property were measured. Measurement results, Table 1
The photovoltaic element of Example 21 (element No. Ex. 21) had an open circuit voltage of 1.03 times the initial characteristic and a fill factor of 1.
03 times, the photoelectric conversion efficiency of the low illuminance characteristic was 1.08 times, and the decrease of the photoelectric conversion efficiency of the durability characteristic was 1.09 times, and it was found that further excellent characteristics were obtained.

(Example 45) A photovoltaic element of the present invention was produced by the multi-chamber separation type deposition apparatus shown in Fig. 4-3. In the figure, 1201 and 1212 are load and unload chambers, 12
02, 1203, 1205 to 1209 and 1211 are deposition chambers for each layer by the RF plasma CVD method similar to those of the embodiment 42, 1204 and 1210 are deposition chambers for each layer by the same microwave plasma CVD method as that of the embodiment 24, 1221.
~ 1231 are gate valves for separating the chambers, 1241 and 1
Reference numerals 242, 1244 to 1248 and 1250 denote cathode electrodes, and 1243 and 1249 are microwave waveguides and dielectric windows.

First, the substrate is set in the load chamber 1201 and
After the inside of the load chamber 1201 is evacuated, the gate valve 1221 is opened to load the substrate into the first n-type layer deposition chamber 1202.
And the gate valve 1221 was closed. Then, the first n-type layer was formed on the substrate under the same conditions as in the first n-type layer of Example 43.
A mold layer was prepared. The gate valve 1222 is opened, and the substrate is placed in the i-type layer deposition chamber 12 by the first RF plasma CVD method.
03, and closed the gate valve 1222. Then, i according to the first RF plasma CVD method of Example 43
Under the same conditions as the mold layer 1, the i-type layer 1 was formed on the first n-type layer by the first RF plasma CVD method. The gate valve 1223 is opened and the substrate is exposed to the first microwave plasma C
After moving to the i-type layer deposition chamber 1204 by the VD method, the gate valve 1223 was closed. Then, under the same conditions as for the i-type layer formed by the first microwave plasma CVD method of Example 43,
An i-type layer formed by the first microwave plasma CVD method was formed on the i-type layer 1 formed by the first RF plasma CVD method.
Further, the gate valve 1224 is opened to set the substrate to the first R
The i-type layer deposition chamber 1205 by the F plasma CVD method is moved to, the gate valve 1224 is closed, and the first microwave plasma CVD method is performed under the same conditions as the i-type layer 2 by the first RF plasma CVD method of Example 43. On the i-type layer by
Then, the i-type layer 2 was formed by the RF plasma CVD method.

The gate valve 1225 was opened, the substrate was moved to the deposition chamber 1206 for the doping layer B1 of the first p-type layer, and the gate valve 1225 was closed. First of Example 43
The first p-type layer doping layer B1 was formed on the i-type layer 2 by the first RF plasma CVD method under the same conditions as the p-type layer doping layer B1. Next, the gate valve 1226 is opened, the substrate is moved to the deposition chamber 1207 for the doping layer A of the first p-type layer, the gate valve 1226 is closed, and then the first p-type layer doping layer of Example 43. Under the same conditions as for A, the first p-type layer doping layer A was formed on the first p-type layer doping layer B1. Further, the gate valve 1227
Was opened, the substrate was moved to the first p-type layer doping layer B2 deposition chamber 1208, and the gate valve 1227 was closed. A first p-type layer doping layer B2 was formed on the first p-type layer doping layer A under the same conditions as the first p-type layer doping layer B2 of Example 43.

[0380] The gate valve 1228 is opened, the substrate is moved to the second n-type layer deposition chamber 1209, and the gate valve 12
28 was closed. Then, the second n-type layer was formed on the first p-type layer doping layer B2 under the same conditions as those of the second n-type layer of Example 43.
A mold layer was prepared. The gate valve 1229 was opened, the substrate was moved to the second i-type layer deposition chamber 1210, and the gate valve 1229 was closed. A second i-type layer was formed on the second n-type layer under the same conditions as for the second i-type layer of Example 43. Next, the gate valve 1230 is opened, the substrate is moved to the second p-type layer deposition chamber 1211, the gate valve 1230 is closed, and the second i-type layer is formed under the same conditions as those for the second p-type layer of Example 43.
A second p-type layer was formed on the mold layer.

The gate valve 1231 was opened, the substrate was moved to the unload chamber 1212, the gate valve 1231 was closed, the substrate was taken out of the unload chamber 1212, and a photovoltaic element was prepared (element No. 45).

The manufactured photovoltaic element (element No. 45)
In the same manner as in Example 24, initial characteristics, low illuminance characteristics and durability characteristics were measured. As a result of the measurement, as compared with the photovoltaic element of Example 43 (element No. 43), the photovoltaic element of Example 45 (element No. 45) had an initial characteristic open circuit voltage of 1.01 times and a curved line. The factor is 1.02 times, the photoelectric conversion efficiency of the low illuminance characteristic is 1.03 times, and the decrease of the photoelectric conversion efficiency of the durability characteristic is 1.02 times excellent, and the photovoltaic element of the present invention is multi-chamber separated type deposition. It was found that a photovoltaic device having excellent characteristics can be obtained by manufacturing the device, and the effect of the present invention was verified.

(Example 46) A photovoltaic element was produced under the same production conditions as in Example 43, and a solar cell module was produced using the photovoltaic element, and a vehicle-mounted ventilation system having a circuit configuration as shown in Fig. 9-2 was produced. Made a fan. In FIG. 9-2, the electric power generated in the solar cell module 9101 attached to the hood of the automobile passes through the backflow prevention diode 9102,
The secondary battery 9104 is charged. Reference numeral 9103 is an overcharge prevention diode. Electric power from the solar cell module 9101 and the secondary battery 9104 is supplied to the motor 9105 of the ventilation fan.

Further, a photovoltaic element was produced under the same production conditions as in Example 20, and an in-vehicle ventilation fan was similarly produced using the photovoltaic element.

An automobile equipped with an on-vehicle ventilation fan manufactured by using the photovoltaic elements of Examples 43 and 20 was left for 168 hours in an idling state in which the engine was rotated,
After that, the engine was stopped in fine weather and left in a state where the ventilation fan was operated, and the temperature inside the automobile was measured. As a result, as compared with the vehicle-mounted cooling fan manufactured using the photovoltaic element of Example 20, the vehicle-mounted cooling fan using the photovoltaic element of Example 43 has a lower indoor temperature of 4 degrees and higher performance. It turned out that various power generation systems can be obtained

[0386]

As described above, the photovoltaic device of the present invention prevents recombination of photoexcited carriers, improves the open circuit voltage and the carrier range of holes, and improves the photoelectric conversion efficiency. Further, the photovoltaic device of the present invention has improved conversion efficiency even when the irradiation light is weak. The photovoltaic element of the present invention is less likely to have a reduced photoelectric conversion efficiency when annealed under vibration for a long time.

Further, according to the method for forming a photovoltaic element of the present invention, a photovoltaic element having the above effects can be formed in good yield.

In addition, the power supply system using the photovoltaic element of the present invention exhibits excellent electricity supply capability even when the irradiation light is weak.

[Table 1]

[Table 2]

[Table 3]

[Table 4]

[Table 5]

[Table 6]

[Table 7]

[Table 8]

[Table 9]

[Table 10]

[Table 11]

[Table 12]

[Table 13]

[Table 14]

[Table 15]

[Table 16]

[Table 17]

[Table 18 (1)]

[Table 18 (Part 2)]

[Table 19]

[Table 20]

[Table 21]

[Table 22]

[Table 23]

[Table 24]

[Table 25]

[Table 26]

[Table 27]

[Table 28]

[Brief description of drawings]

FIG. 1 is a schematic explanatory view for explaining a layer structure of a photovoltaic element of the present invention.

FIG. 2 is a schematic explanatory diagram for explaining a change in bandgap of the photovoltaic element of the present invention.

FIG. 3 is a schematic explanatory diagram for explaining a change in bandgap of the photovoltaic element of the present invention.

FIG. 4 is a schematic explanatory view showing an example of an apparatus for producing the photovoltaic element of the present invention. (1) Manufacturing apparatus by microwave plasma CVD method (2) Manufacturing apparatus by RF plasma CVD method (3) Manufacturing apparatus by multi-chamber separation type deposition apparatus

FIG. 5 is a graph showing changes over time in SiH ₄ and GeH ₄ gas flow rates during the production of an i-type layer.

FIG. 6 is a graph showing a band gap in the layer thickness direction of an i-type layer.

FIG. 7 is a graph showing (1) time change of SiH ₄ gas flow rate during production of an i-type layer, and (2) distribution of Si atoms and H atoms in the i-type layer in the layer thickness direction.

FIG. 8 is a graph showing changes over time in SiH ₄ and GeH ₄ gas flow rates during the production of an i-type layer.

FIG. 9 is a schematic explanatory diagram for explaining the power supply system of the present invention.

FIG. 10 is a graph showing (1) time change of NO / He gas flow rate at the time of producing an i-type layer, and (2) distribution of N atoms and O atoms in the i-type layer in the layer thickness direction.

FIG. 11 is a graph showing changes over time in SiH ₄ and GeH ₄ gas flow rates during the production of an i-type layer.

FIG. 12 is a graph showing changes over time in SiH ₄ and GeH ₄ gas flow rates during the production of an i-type layer.

FIG. 13 is a graph showing changes over time in the SiH ₄ and GeH ₄ gas flow rates during the production of the i-type layer.

FIG. 14: BF ₃ / H ₂ gas, PH ₃ (2
(000 ppm) / H ₂ gas flow rate over time and a graph showing the distribution of B atoms and P atoms in the i-type layer in the layer thickness direction.

[Explanation of symbols]

101 conductive substrate 102 n-type silicon-based non-single-crystal semiconductor layer 103 i-type non-single-crystal semiconductor layer by microwave plasma CVD method 104 p-type silicon-based non-single-crystal semiconductor layer 105 transparent electrode 106 current collecting electrode 108, 109 i-type non-single crystal semiconductor layer by RF plasma CVD method 211, 212, 221, 222 i-type non-single crystal semiconductor layer by microwave plasma CVD method 213, 223 i-type non-single crystal layer by RF plasma CVD method Crystal semiconductor layers 311, 321, 331, 341, 351, 361, 3
71 Areas where band gap changes 312, 313, 322, 323, 332, 333, 3
42, 343, 352, 353, 362, 363, 37
2, 373, 374 Band gap constant region 1000 Microwave plasma CVD method film forming apparatus 1001 Deposition chamber 1002 Dielectric window 1003 Gas introduction tube 1004 Substrate 1005 Heater 1006 Vacuum gauge 1007 Conductance valve 1008 Auxiliary valve 1009 Leak valve 1010 Waveguide part 1011 Bias power supply 1012 Bias rod 1013 Shutter 1020 Raw material gas supply device 1021-1029 Mass flow controller 1031-1039 Gas inflow valve 1041-1049 Gas outflow valve 1051-1059 Raw material gas cylinder valve 1061-1069 Pressure regulator 1071-1079 Raw material Gas cylinder 1100 RF plasma CVD film forming apparatus 1101 Deposition chamber 1102 Cathode 1103 Gas Introducing pipe 1104 Substrate 1105 Heater 1106 Vacuum gauge 1107 Conductance valve 1108 Auxiliary valve 1109 Leak valve 1111 RF power supply 1112 RF matching box 1201, 1209 load, unload chamber 1202-1208 Deposition chamber 1211-1218 Gate valve 1221, 1223-1225, 1227 Cathode electrode 1222, 1226 Microwave waveguide and dielectric window 9001 Photovoltaic element 9002 Voltage control diode 9003 Voltage stabilizing capacitor 9004 Load 9101 Solar cell 9102 Backflow prevention diode 9103 Voltage control circuit 9104 Secondary battery 9105 load 9401 diesel generator 9402 solar cell 9403 rectifier 9404 charge / discharge control device 9405 storage battery 406 DC / AC converter 9407 Switcher 9408 AC load 9501 Solar cell 9502 Charge / discharge control device 9503 Storage battery 9504 DC / AC converter 9505 Commercial power source 9506 Instantaneous step switch 9507 Load 9601 Solar cell 9602 DC / AC converter 9603 Commercial power source 9604 Load 9605 Reverse flow

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Mitsuyuki Niwa 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Masafumi Sano 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon (72) Inventor Ryo Hayashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (13)

[Claims] 1. A photovoltaic element comprising at least a p-type layer made of a silicon-based non-single-crystal semiconductor material, a photoconductive layer (a layer made of a plurality of i-type layers), and an n-type layer. The photoconductive layer includes an i-type layer deposited on the p-type layer side by a microwave plasma CVD method and the n-type layer.
A laminated structure including at least an i-type layer deposited on the mold layer side by an RF plasma CVD method, wherein the i-type layer deposited by the microwave plasma CVD method contains at least silicon atoms and germanium atoms. However, the position of the minimum value of the band gap is the i-type layer formed in the p-type layer direction with a shift from the center of the i-type layer, and the RF
The i-type layer deposited by the plasma CVD method contains at least silicon atoms and has a layer thickness of 30 nm or less, and at least one of the p-type layer and the n-type layer has a periodic table index.
A photovoltaic device having a laminated structure of a layer containing a group III element or a group V element as a main constituent element and a layer containing a valence electron control agent and a silicon atom as a main constituent element. 2. The i-type layer deposited by the microwave plasma CVD method is simultaneously doped with a valence electron control agent which serves as a donor and a valence electron control agent which serves as an acceptor. Photovoltaic device. 3. The valence electron control agent serving as the donor is an element belonging to Group III of the periodic table, and the valence electron control agent serving as the acceptor is a group V element. Photovoltaic device according to. 4. The photovoltaic device according to claim 2, wherein the valence electron control agent is distributed in the layer. 5. The i-type layer deposited by the microwave plasma CVD method has a maximum bandgap in at least one of a p-type layer direction and an n-type layer direction from the center of the i-type layer, The region of the maximum value of the band gap is 1 or more and 30 nm or less.
The photovoltaic element according to any one of items 1 to 4. 6. The i-type layer formed by the microwave plasma CVD method and / or the i formed by the RF plasma CVD method
The photovoltaic element according to any one of claims 1 to 5, wherein the mold layer contains oxygen atoms and / or nitrogen atoms. 7. The hydrogen content contained in the i-type layer formed by the microwave plasma CVD method changes according to the content of silicon atoms.
The photovoltaic element according to any one of 1. 8. The p-type layer and the microwave plasma C
The photovoltaic element according to claim 1, wherein an i-type layer formed by an RF plasma CVD method is provided between the photovoltaic element and the i-type layer formed by the VD method. 9. The layer thickness of the layer containing a Group III element or / and a Group V element of the periodic table as a main constituent element is 1 nm or less, wherein the layer thickness is 1 nm or less. The photovoltaic element according to the item. 10. A p-type layer made of a silicon-based non-single-crystal semiconductor material, a photoconductive layer (layer made of a plurality of i-type layers), and n.
In the method of manufacturing a photovoltaic element configured by stacking at least mold layers, the i-type layer on the p-type layer side of the photoconductive layer is
Microwave energy lower than microwave energy required for 100% decomposition of the raw material gas and RF higher than the microwave energy in a raw material gas containing at least a silicon atom-containing gas and a germanium atom-containing gas at a pressure of 50 mTorr or less. By the microwave plasma CVD method in which the energy and the energy are simultaneously applied, formation and deposition are performed such that the position of the minimum value of the band gap is offset from the central position of the i-type layer toward the p-type layer, and the i-type on the n-type layer side is formed. The mold layer is 2 nm / sec by RF plasma CVD using a source gas containing at least a silicon atom-containing gas.
A layer having a deposition rate of 30 nm or less and at least one of the p-type layer and the n-type layer containing a Group III element or a Group V element of the periodic table as a main constituent element; A method for manufacturing a photovoltaic element, which comprises forming a laminated structure with a layer containing silicon atoms as a main constituent element. 11. The valence electron control agent serving as a donor and the valence electron control agent serving as an acceptor are simultaneously doped when the i-type layer on the p-type layer side of the photoconductive layer is formed. Item 10. A method for forming a photovoltaic element according to Item 10. 12. The photovoltaic element according to claim 10, wherein the silicon atom-containing gas and the germanium atom-containing gas are mixed at a distance of 5 m or less from the deposition chamber in the microwave plasma CVD method. Production method. 13. A photovoltaic element according to any one of claims 1 to 9, and a storage battery for accumulating the electric power supplied from the photovoltaic element and / or supplying the electric power to an external load. And a control system for monitoring the voltage and / or current of the photovoltaic element and controlling the power supplied from the photovoltaic element to the storage battery and / or the external load. Power generation system.