JP3490969B2 - Photovoltaic generator - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a photovoltaic device. In the present specification, the pin junction has a structure in which n-type, i-type, and p-type semiconductor layers are sequentially formed from inside to outside or from outside to inside of a substantially spherical photoelectric conversion element. Must be construed as including.

[0002]

2. Description of the Related Art A typical first prior art includes a photoelectric conversion element made of a crystalline silicon semiconductor wafer. In this first prior art, the process for producing the crystal is complicated,
The cost is high. Also, cutting from single crystal bulk,
Since the semiconductor wafer is manufactured through processes such as slicing and polishing, the process is complicated, and the crystal chips generated in the processes such as cutting, slicing and polishing are about 50% or more in volume ratio. Would be wasted.

Another second prior art solution to this problem is:
It is composed of an amorphous Si (abbreviated as a-Si) thin film. In the second prior art, since the photoelectric conversion layer is formed in a thin film form by the plasma chemical vapor deposition method, the steps of cutting, slicing, polishing and the like from the conventional single crystal bulk are unnecessary, and the deposited film is formed. All of the above can be used as an active layer of the device. On the other hand, the amorphous Si solar cell has a problem that a large number of crystal defects, that is, gap states exist inside the semiconductor due to the amorphous structure, and therefore, a photo-induced deterioration phenomenon exists and the photoelectric conversion efficiency decreases. . In order to solve this problem, conventionally, a technique of deactivating by hydrogenation has been developed, and electronic devices such as amorphous Si solar cells can be manufactured.

However, even with such processing,
It is impossible to eliminate the effect of crystal defects, and for example, amorphous Si solar cells still have a crying point that the photoelectric conversion efficiency deteriorates by about 15 to 25%.

As a recently succeeded new technology for suppressing photodegradation, a stack type solar cell in which the photoelectrically active i-layer is extremely thin and the solar cell has two junctions or three junctions has been realized. Succeeded in suppressing to about%. It is clear that the photodegradation recovers from the photodegradation when the operating temperature of the solar battery cell is high, and a module technology for operating / operating in such a state is being developed, but it cannot be said to be sufficient.

[0006] Yet another third solution to such a problem
The prior art is disclosed in Japanese Patent Publication No. 7-54855. In the third prior art, spherical particles having an n-type Si skin portion on a p-type Si sphere are embedded in a flat aluminum foil with holes, and the n-type Si skin portion is etched from the back surface of the aluminum foil to form an internal portion. Exposing the p-type Si spheres, and connecting the exposed p-type Si spheres to another aluminum foil to form a solar array.

In the third prior art, in order to reduce the amount of high-purity Si used and reduce the cost, it is necessary to reduce the outer diameter of the particles and reduce the average thickness of the whole. Further, in order to improve the conversion efficiency, it is necessary to make the light receiving surface large, and in order to make the light receiving surface large, the particles are arranged close to each other, and therefore a large number of particles having a small outer diameter are densely packed. It must be placed and connected to aluminum foil. As a result, the process of connecting the particles and the aluminum foil becomes complicated, and the cost is reduced.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to reduce the amount of high-purity semiconductor material such as Si used and to facilitate mass production, that is, to enable resource-saving and energy-saving manufacturing. And to provide a highly reliable and highly efficient photovoltaic power generation device that can be realized at low cost.

[0009]

According to the present invention, (a) an opening of a second semiconductor layer having a substantially spherical shape, a first semiconductor layer and a second semiconductor layer outside the first semiconductor layer is provided. A part of the first semiconductor layer is exposed from the opening, and the opening of the second semiconductor layer and the part of the first semiconductor layer exposed from the opening are
A plurality of photoelectric conversion elements that are on a single plane and output a photovoltaic force from the first and second semiconductor layers; and (b) a support, which is between the first conductor and the second conductor,
An electrically insulated state is formed through an electrical insulator,
A plurality of recesses having an inner surface formed of the first conductor or the coating layer formed on the first conductor are formed adjacent to each other, and the photoelectric conversion element is arranged at the bottom of each recess to form the first conductor of the recess or The photoelectric conversion element is irradiated with the light reflected by the coating layer formed on the first conductor, the first conductor is electrically connected to the second semiconductor layer of the photoelectric conversion element, and the second conductor is the first semiconductor layer.
A photovoltaic device, comprising: a support electrically connected to the exposed portion of the semiconductor layer.

According to the present invention, a plurality of substantially spherical photoelectric conversion elements are respectively arranged in a plurality of concave portions of the support, and the inner surface of the concave portions is formed on the first conductor or on the first conductor. The photoelectric conversion element is directly irradiated with light from the outside, such as sunlight, which is formed by the coating layer, and is reflected by the first conductor on the inner surface of the recess or the coating layer formed on the first conductor to generate photoelectric light. The conversion element is illuminated.

Since the photoelectric conversion elements are arranged in the recesses, they are provided with a space therebetween, that is, the photoelectric conversion elements are not arranged densely. Therefore, it is possible to reduce the number of photoelectric conversion elements and reduce the amount of high-purity material such as Si that constitutes the photoelectric conversion elements, and to facilitate the step of connecting the photoelectric conversion elements and the conductor of the support. can do.

Moreover, the plurality of recesses are formed adjacent to each other, whereby the light from the outside is reflected on the inner surface of the recess and irradiates the photoelectric conversion element, so that the light from the outside can be effectively used. It can be used for the generation of photovoltaics. In this way, the generated power per unit area facing the light source of the photoelectric conversion element of the present invention can be maximized.

The photoelectric conversion element of the present invention may be made of a single crystal, polycrystal, or amorphous material, and may be made of a silicon-based material, a compound semiconductor-based material, or another material. For example, a pn-type or a pin-type. Other structures such as a Schottky barrier type, M
It may have an IS (metal-insulator-semiconductor) type, a homojunction type, a heterojunction type, and other configurations.

The first semiconductor layer on the center side is partially exposed from the opening of the second semiconductor layer on the outer side.
Further, the photoelectromotive force generated at the time of light irradiation can be extracted from the second semiconductor layer. The second semiconductor layer of the photoelectric conversion element arranged in the recess of the support is electrically connected to the first conductor of the support. The exposed portion of the first semiconductor layer inside the photoelectric conversion element is electrically connected to the second conductor provided via the electrical insulator with the first conductor. First conductor and second
In the structure in which the conductor is formed in a planar shape, the plurality of photoelectric conversion elements are connected in parallel by the first and second conductors, and a large current can be derived.

Although the photoelectric conversion element may be a true sphere, it does not have to be a true sphere as long as the outer surface thereof is a substantially spherical shape other than the true sphere. The first semiconductor layer may be formed in a solid, substantially spherical shape, but in another embodiment of the present invention, the outer peripheral surface of the core body prepared in advance is covered with the first semiconductor layer. Or it may have a configuration in which the cavity near the center of the substantially spherical first semiconductor layer is a cavity.

In the present invention, the outer diameter of the photoelectric conversion element is
It is characterized in that it is 0.5 to 2 mmφ.

According to the present invention, the outer diameter of the photoelectric conversion element is
0.5 to 2 mmφ, preferably 0.8 to 1.2 m
mφ, or alternatively about 1 mmφ.
This makes it possible to sufficiently reduce the amount of materials such as high-purity Si used and to increase the generated power as much as possible. At the same time, the spherical photoelectric conversion element can be easily handled at the time of manufacturing, resulting in excellent productivity. ing.

The present invention is also characterized in that the central angle θ1 of the opening of the second semiconductor layer is 45 to 90 °.

According to the present invention, as described above, the central angle θ1
By 45 to 90 °, more preferably 60 to 90 °, the amount of the first and second semiconductor layers discarded due to the formation of the opening is reduced and waste is suppressed. be able to. Moreover, the central angle θ1
Is selected in such a range, the area of the opening required for electrical connection between the first semiconductor layer and the second conductor of the support can be obtained.

Further, according to the present invention, the opening end of the recess formed in the support is, for example, a honeycomb-shaped polygon, and the opening ends adjacent to each other are continuous, and the recess is tapered toward the bottom. And electrically connecting the first and second semiconductor layers of the photoelectric conversion element to the second and first conductors electrically insulated from each other at or near the bottom of the recess. Is characterized by.

Further, according to the present invention, a circular first connecting hole 39 is formed in the first conductor at the bottom of the concave portion of the support or in the vicinity thereof, and the first connecting hole 39 is formed in the electric insulator. Circular second connection hole 4 having an axis on a straight line including the axis
0 is formed, and in the vicinity of the opening of the photoelectric conversion element, the first
The outer peripheral surface of the upper part of the opening of the second semiconductor layer is fitted into the connection hole 39, and the end surface of the first conductor and the portion near the end surface of the first connection hole 39 are electrically connected to each other, and from the opening. The exposed portion of the first semiconductor layer is electrically connected to the second conductor via the second connection hole 40.

In the present invention, the outer diameter of the photoelectric conversion element is set to D1.
When the inner diameter of the opening of the second semiconductor layer is D2, the inner diameter of the first connection hole 39 is D3, and the inner diameter of the second connection hole 40 is D4, then D1>D3>D2> D4 should be selected. Is characterized by.

According to the invention, the first connection hole 3 of the first conductor 3
9, the photoelectric conversion element is fitted in the vicinity of the opening, and the part of the first semiconductor layer exposed from the opening is exposed through the second connection hole 40 formed in the electrical insulator of the support body to the second connection hole 40. It is electrically connected to the two conductors. Thus, the first and second conductors of the support having the first conductor, the electrical insulator, and the second conductor can be electrically easily connected to the second and first semiconductor layers of the photoelectric conversion element, respectively. become.

Regarding the electrical connection between the second semiconductor layer and the first conductor, the outer peripheral surface of the upper portion of the opening 9 of the second semiconductor layer above the opening 9 of FIG. The end surface of the first connection hole 39 or a portion near the end surface, that is, the inner peripheral surface of the first connection hole 39 and / or the portion surrounding the first connection hole 39 near the first connection hole 39 is electrically connected. .

Even if the second conductor 14 is inserted through the second connection hole 40 into the portion 10 exposed from the opening 9 of the first semiconductor layer 7 and is, for example, raised and plastically deformed, it is electrically connected. Well, or may be electrically connected to the second conductor 14 by a conductive paste provided in the second connection hole 40, or by a conductive bump such as a metal.

The outer diameter D1 and the inner diameter D2, D
By selecting 3 and D4 according to the above-mentioned inequalities, undesired electrical short circuits can be prevented and reliable electrical connection can be achieved.

Further, in the present invention, the area of the opening end of the concave portion of the support is S1, and the cross-sectional area including the center of the photoelectric conversion element is S2.
Then, the light collection ratio x = S1 / S2 is selected to be 2 to 8.

In the present invention, the outer diameter of the photoelectric conversion element is
When the area of the opening end of the concave portion of the support is S1 and the cross-sectional area including the center of the photoelectric conversion element is S2, the light collection ratio x = S1 / S2 is 2 to 8 Characterized by choosing.

In the present invention, the outer diameter of the photoelectric conversion element is
0.8 to 1.2 mmφ, the area of the opening end of the concave portion of the support is S1, and the cross-sectional area including the center of the photoelectric conversion element is S1.
When 2, the light collection ratio x = S1 / S2 is selected to be 4 to 6.

According to the invention, the open end of the recess of the support is, for example, a honeycomb-shaped polygon, which may be, for example, a hexagon, the recess being tapered toward the bottom, A photoelectric conversion element is arranged on the bottom, and the photoelectric conversion element is connected to each conductor of the support at or near the bottom of the recess. The open end of the recess is polygonal,
When the opening ends are continuous, the photoelectric conversion element can be irradiated with all the light received on the entire surface of the support, which faces the light source such as sunlight, except for the position of the photoelectric conversion element. Therefore, the light collection ratio x = S1 / S2 is set to, for example, 2 to 8 times, and preferably 4 to 6 times,
So to speak, a condensing photoelectric conversion element can be realized. As a result, as described above, the distance between the photoelectric conversion elements can be increased, the number of photoelectric conversion elements can be reduced, and the process of electrically connecting with the support can be simplified. Therefore, the amount of the high-purity semiconductor used as the material for the photoelectric conversion element can be reduced, and the present invention can be implemented at low cost. The structure of the support is relatively simple, has excellent productivity, and is easy to manufacture.

For example, according to an experiment by the present inventors, a photoelectric conversion element made of substantially spherical Si has an outer diameter of 800.
In the photovoltaic device of the present invention formed so as to have a diameter of ˜1000 μmφ, if the condensing ratio x is 4 to 6 times, Si of the same weight as Si constituting all photoelectric conversion elements used in the photovoltaic device, Virtually, the thickness when converted into a flat plate having an area equal to the projected area on the virtual plane perpendicular to the light beam from the light source to the photovoltaic device is about 90 to 120 μm, and therefore Si of 1 W of generated power is obtained. It was possible to obtain the epoch-making result that the amount used was less than 2 g. In the first prior art of the photoelectric conversion element composed of the crystalline silicon semiconductor wafer described above, the thickness of the crystalline silicon is 35.
0 to 500 μm, and including slice loss is about 1
mm. Therefore, in the first prior art, the generated power 1
The amount of Si used per W is about 15 to 20 g. Therefore, in the present invention, the amount of Si used can be significantly reduced compared to the above-mentioned first prior art.

If the light collection ratio x is a value exceeding 8, the required number of photoelectric conversion elements can be reduced and the generated power of 1 W
Although it is possible to further reduce the amount of Si used per unit, on the other hand, actually, the ratio of the light energy incident on the concave portion to the light energy absorbed by the photoelectric conversion element is increased with the increase of the light collection ratio x. The light collection efficiency becomes poor, resulting in a decrease in performance.

Further, according to the present invention, as described above, the outer diameter of the photoelectric conversion element is selected to be 0.5 to 2 mmφ, preferably 0.8 to 1.2 mmφ, and the light collection ratio x is set to
By selecting 2 to 8, preferably 4 to 6,
The number of photoelectric conversion elements is reduced, and Si per 1 W of generated power is reduced.
It is possible to reduce the amount of use of the photoelectric conversion element and to further simplify the process of electrically connecting the photoelectric conversion element and the support. In this way, the combination with the numerical selection of the outer diameter of the photoelectric conversion element is important in order to reduce the number of photoelectric conversion elements and the amount of Si used per 1 W of generated power.

If the outer diameter of the photoelectric conversion element is less than 0.5 mmφ, the amount of Si used is reduced, but the required number of photoelectric conversion elements increases, and if the outer diameter exceeds 2 mmφ, Although the required number of conversion elements is reduced, Si
Will be used more.

When the light collection ratio x is less than 2, the amount of Si used cannot be sufficiently reduced, and when it exceeds 8, the light collection efficiency is deteriorated to less than 80%, for example, resulting in deterioration of performance. Become. In the present invention, the light collection efficiency is set to 80% or more by further selecting the light collection ratio x within the above range, and further 90
You will be able to make it more than%.

Thus, according to the present invention, the outer diameter of the photoelectric conversion element and the light collection ratio x are selected within the above-mentioned range of numerical values, whereby the required number of photoelectric conversion elements is increased as compared with the third prior art. Also, the outstanding effect that the amount of Si used per 1 W of generated power can be drastically reduced to 1/5 to 1/10 is achieved.

Further, according to the present invention, in the configuration in which the amorphous Si photoelectric conversion element is used to collect light at the above-described light collection ratio, the temperature of the photoelectric conversion element is raised as compared with the photoelectric conversion element of the amorphous Si thin plate, and the temperature is, for example, 40 to 40. It can be 80 ° C. As a result, it is possible to suppress the deterioration of the amorphous Si photoelectric conversion element and make it have a long life.

Further, according to the present invention, as shown in FIG. 14, the photoelectric conversion element includes a photoelectric conversion element of the other conductivity type having an optical bandgap wider than that of the first semiconductor layer outside the first semiconductor layer 64 of the one conductivity type. The second semiconductor layer 65 is formed and has a pn junction.

Further, according to the present invention, as shown in FIGS. 15 and 16, the photoelectric conversion element includes a first conductive type semiconductor layer 6 of one conductivity type.
Amorphous intrinsic semiconductor layers 69, 7 on the outside of 8, 73
4 and the second conductive type amorphous second semiconductor layers 70, 7 having an optical bandgap wider than that of the first semiconductor layers.
6 are formed in this order and have a pin junction.

According to the present invention, the first semiconductor layer is n-type Si.
And the second semiconductor layer is p-type amorphous SiC.

The present invention also provides an n-type S that is the first semiconductor layer.
i is characterized by being n-type crystalline Si or n-type microcrystalline (μc) Si.

According to the present invention, a heterojunction window structure of pn or pin is formed by different kinds of amorphous semiconductors. The optical bandgap of the second semiconductor layer of the window material existing on the light incident side is made wider than that of the inner first semiconductor layer, whereby the light absorption coefficient of the second semiconductor layer is made smaller and the second semiconductor layer is made smaller. Prevents light from being absorbed in the layer, reduces recombination of electrons and holes in the surface layer, reduces light absorption loss, and increases sensitivity on the short wavelength side to achieve a wide-gap window effect. The energy conversion efficiency can be improved.

Particularly, in the pin junction structure, more light energy is introduced into the intrinsic semiconductor layer (i layer) which is the photovoltaic generation layer, and the sensitivity on the short wavelength side is increased to achieve the wide gap window function. You can In the present invention, an extremely excellent energy conversion operation is performed as compared with the particles in which the n-type Si skin portion is formed outside the p-type Si sphere in the above-mentioned prior art.

In the i-layer of the photoelectric conversion element having a pin junction, light is absorbed to form an electron-hole pair to generate and transport a photocurrent, and the p-layer and the n-layer serve as a Fermi level. Is fixed near the valence band and the conduction band, and plays a role of collecting photogenerated carriers by creating an internal electric field that carries electrons and holes generated in the i layer to both electrodes. In this way, the energy conversion efficiency is improved.

Further, according to the present invention, as shown in FIG. 17, the photoelectric conversion element has an inner cell 81 having an innermost first semiconductor layer.
And an outer cell 82 having an outermost second semiconductor layer formed outside the inner cell, and having a stack structure.

Further, the present invention is characterized in that the inner cell 81 has a pn junction layer or a pin junction layer, and the outer cell 82 has a pn junction layer or a pin junction layer.

Further, according to the present invention, the internal cell 81 comprises, in order from the inside to the outside, the first semiconductor layer 84 of one conductivity type and the amorphous and / or microcrystalline semiconductor layer 8 of the other conductivity type.
5, the outer cell 82 includes, in order from the inside to the outside, an amorphous pin junction layer 86 and an amorphous or microcrystalline second semiconductor layer 87 having an optical bandgap wider than that of the pin junction layer. Is characterized by.

Further, according to the present invention, as shown in FIG. 18, the internal cell 101 has, in order from the inside to the outside, a first semiconductor layer 104 of one conductivity type and an amorphous and / or microcrystalline semiconductor layer 105 of the other conductivity type. , 106, and the outer cell 102 has, in order from the inside to the outside, a microcrystalline semiconductor layer 107 of one conductivity type, an amorphous intrinsic semiconductor layer 108, and a second semiconductor layer 111 of microcrystal of the other conductivity type. It is characterized by having.

Further, according to the present invention, as shown in FIG. 19, the inner cell 112 has, in order from the inside to the outside, one conductive type amorphous first semiconductor layer 114, an amorphous intrinsic semiconductor layer 115, and the other conductive type amorphous. Semiconductor layer 117
The outer cell 113 has, in order from the inside to the outside, a microcrystalline semiconductor layer 118 of one conductivity type, an amorphous intrinsic semiconductor layer 119, and a second semiconductor layer 122 of microcrystal of the other conductivity type. Is characterized by.

Further, according to the present invention, as shown in FIG. 20, the internal cells 124 are arranged in order from the inside to the outside, on the other hand, a first conductive type amorphous semiconductor layer 126 and a microcrystalline intrinsic semiconductor layer 12.
7 and an amorphous semiconductor layer 129 which is of the other conductivity type and has an optical bandgap wider than that of the first semiconductor layer, and the outer cells 125 are arranged in order from the inside to the outside of the one conductivity type microcrystalline semiconductor layer. 130, the amorphous intrinsic semiconductor layer 131, and the second conductive type microcrystalline second semiconductor layer 1
And 34.

According to the present invention, the microcrystalline (μc) semiconductor layer has a high conductivity, and such a microcrystalline semiconductor layer is formed into the first
The photoelectric conversion efficiency can be improved by introducing it between the semiconductor layer and the pin junction layer. By the amorphous pin junction layer, the amorphous pin
The heterojunction between the junction layer and the second semiconductor layer enables effective collection of photogenerated carriers and mitigation of recombination loss of the photogenerated carriers.

The amorphous semiconductor receives, for example, light reflected by the inner surface of the concave portion of the support, and thus the amorphous semiconductor has, for example, 40
The temperature is raised to ˜80 ° C., which suppresses deterioration of photoelectric conversion characteristics, which is convenient. Since this photoelectric conversion element is formed in a substantially spherical shape, it is possible to suppress an increase in incident energy of light per unit area for receiving the direct light and the reflected light, which also causes deterioration of the photoelectric conversion characteristics. Will be suppressed.

The present invention is also characterized in that the first semiconductor layer is a direct transition type semiconductor layer.

In the present invention, the direct transition type semiconductor layer is I
nAs, GaSb, CuInSe ₂ , Cu (InGa)
Se ₂ , CuInS, GaAs, InGaP, CdTe
It is one type selected from the group consisting of.

According to the invention, the inner first semiconductor layer is
Realized by a direct transition type semiconductor layer that easily absorbs light,
This makes it possible to obtain a sufficient transition probability between electrons and holes, which also improves the photoelectric conversion efficiency.

Further, according to the present invention, a plurality of supports are arranged adjacent to each other, and the peripheral portions of the respective supports are formed so as to extend outward. The first conductor and the second conductor of the other support are overlapped and electrically connected.

Further, the present invention is characterized in that each of the peripheral portions has a rising portion or a falling portion, and the rising portions or the falling portions are overlapped and electrically connected.

According to the present invention, the first conductor of one support and the second conductor of the other support are overlapped and connected at the peripheral portion of the plurality of supports on which the photoelectric conversion elements are mounted, In this way, the photovoltaic power generated by the photoelectric conversion elements for each support can be connected in series to extract a desired high voltage.

According to the present invention, FIGS.
As shown in FIG. 3, the rising part and the falling part of the peripheral portion of the support are overlapped and electrically connected, or the rising parts are electrically connected or the falling parts are electrically connected. Good. This makes it possible to arrange the recesses of the support member close to each other and arrange as many recesses and photoelectric conversion elements as possible in a limited area.

[0060]

1 is an enlarged sectional view of a part of a photovoltaic device 1 according to an embodiment of the present invention, and FIG. 2 is a sectional view showing the entire structure of the photovoltaic device 1. FIG. 3 is an exploded perspective view of the photovoltaic device 1 shown in FIG. Photovoltaic device 1
Is basically a combination of a plurality of photoelectric conversion elements 2 each having a substantially spherical shape and a support 3 on which the photoelectric conversion elements 2 are mounted.
It is embedded in a filling layer 5 made of VB (polyvinyl butyral), EVA (ethylene vinyl acetate) or the like, and in this filling layer 5, a translucent protective sheet 6 such as polycarbonate is arranged on the light source side such as sunlight. Fixed.
A waterproof back sheet 12 made of a synthetic resin material or the like is provided on the surface of the filling layer 5 opposite to the protective sheet 6 (downward in FIG. 1).
Is fixed. Thus, the overall shape of the photovoltaic device 1 is
It has a flat plate shape.

The photoelectric conversion element 2 has a first semiconductor layer 7 and a second semiconductor layer 8 outside thereof. An opening 9 is formed in the second semiconductor layer 8. A portion 10 of the first semiconductor layer 7 is exposed from the opening 9 downward in FIG. 1. Figure 1
By irradiating the light 11 from above, the photovoltaic power is output from between the first and second semiconductor layers 7 and 8 of the photoelectric conversion element 2.

The support 3 includes a first conductor 13 and a second conductor 14.
An electrical insulator 15 is sandwiched between the first and second conductors 13 and 14 and electrically insulated from each other via the electrical insulator 15. The first and second conductors 13 and 14 may be, for example, aluminum foil or other metal sheets. The electric insulator 15 may be a synthetic resin material such as polyimide, or may be made of another electric insulating material. The plurality of recesses 17 are formed adjacent to each other, and the inner surface of the recess 17 is formed by the first conductor 13. The photoelectric conversion element 2 is arranged at the bottom of each recess 17.

FIG. 4 is a plan view of a part of the support 3.
The open end 18 of the recess 17 is polygonal, for example, a honeycomb-shaped regular hexagon in this embodiment, and in another embodiment of the present invention, it may be another polygon such as a triangle or more. Good. In FIG. 4, the length W1 of the open end 18 may be, for example, 2 mm. The open ends 18 adjacent to each other are continuous, that is, the recesses 17 are connected by the inverted U-shaped bent portions 19 in FIG. Light 1
1. As many recesses 17 as possible can be formed within the area facing 1. Therefore, the first conductor 1 on the inner surface of the recesses 17 can be formed.
The reflected light of 3 can be reflected and guided to the photoelectric conversion element 2, and the light collection ratio can be increased.

The concave portion 17 is formed in a taper shape, for example, in a parabolic shape as it goes to the bottom. At the bottom of the recess 17, the first semiconductor layer 7 of the photoelectric conversion element 2 is connected to the second conductor 14 of the support 3.
Are electrically connected to each other at the connection portion 21. The second semiconductor layer 8 of the photoelectric conversion element 2 is electrically connected to the first conductor 13 of the support body 3 at or near the bottom of the recess.

FIG. 5 is a sectional view showing the photoelectric conversion element 31 in a state before being mounted on the support 3 of the photoelectric conversion element 2. The photoelectric conversion element 31 of FIG. 5 has a sectional structure similar to that of FIG. 1 described above. The first semiconductor layer 7 has a spherical shape and is made of n-type Si. The first semiconductor layer 7 may be amorphous, single crystal or polycrystalline. The second semiconductor layer 8 formed outside the first semiconductor layer 7 is made of p-type Si.
Is. The second semiconductor layer 8 may be amorphous, single crystal or polycrystalline. The second semiconductor layer 8 is
If the optical bandgap is wider than that of the first semiconductor layer 7, for example, p-type a-SiC, a wide gap window action is achieved.

According to another embodiment of the present invention, the first semiconductor layer 7 shown in FIG. 5 is realized by a direct transition type semiconductor layer and has, for example, InAs, Cu having an n-type conductivity type.
InSe ₂ , Cu (InGa) Se ₂ , CuInS, Ga
It may be one type selected from the group consisting of As, InGaP, and CdTe. A second semiconductor layer 8 is formed on the first semiconductor layer 7 formed by the direct transition type semiconductor layer, and the second semiconductor layer 8 includes semiconductors AlGaAs, CuInSe ₂ , Cu (p I
_{nGa) Se 2, GaAs, AlGaP} , is one member selected from a compound semiconductor of group similar CdTe or thereto. In this way, a pn junction structure is formed.

In the step of using the amorphous semiconductor for the first and second semiconductor layers 7 and 8, the i semiconductor layer 69 is formed between the first semiconductor layer 68 and the second semiconductor layer 70 as shown in FIG. 6 described later. However, a pin junction structure may be formed by this.

A method of manufacturing the combination 4 together with the support 3 shown in FIG. 1 using the photoelectric conversion element 31 shown in FIG. 5 will be described below.

FIG. 6 is a cross-sectional view for explaining a method of manufacturing the combination body 4 having the photoelectric conversion element 2 and the support body 3. After the spherical photoelectric conversion element 2 shown in FIG. 5 is manufactured, as shown in FIG.
Is cut. In the photoelectric conversion element 2 shown in FIG. 6, a part 10 of the first semiconductor layer 7 is exposed through the opening 9 of the second semiconductor layer 8. The opening 9 has a central angle θ1.
Is formed in a flat shape in the range of less than 180 °. Central angle θ
1 may be, for example, 45 to 90 °, preferably 60 to 90 °. The outer diameter D1 of the photoelectric conversion element 31 may be, for example, 0.5 to less than 2 mmφ, and more preferably 0.8 to 1.2 mmφ. The inner diameter of the opening 9 is indicated by reference numeral D2. Focusing ratio x = S
1 / S2 is 2 to 8 times, preferably 4 to 6 times.

FIG. 7 is a cross-sectional view for explaining a step of cutting the spherical photoelectric conversion element 31 to form the opening 9. The upper parts of the plurality of spherical photoelectric conversion elements 31 are respectively vacuum-sucked by the suction pads 34 and polished by the endless belt-shaped polishing material 35. The abrasive material 35 is wound around rollers 36 and 37 and driven to rotate. Therefore, the opening 9 of the second semiconductor layer 8 and a part of the first semiconductor layer 7 exposed from the opening 9 are in the same plane as described above.

Referring again to FIG. 6, in manufacturing the support 3, the first conductor 13 of aluminum foil is prepared, and the connection hole 39 is formed in the first conductor 13. Connection hole 3
The inner diameter D3 of 9 is smaller than the outer diameter D1 of the photoelectric conversion element 2 and is larger than the inner diameter D2 of the opening 9 of the second semiconductor layer 8 (D1>D3> D2). Thin plate electrical insulator 1
5 is prepared, and a connection hole 40 is formed in this electric insulator 15. The inner diameter D4 of the connection hole 40 is less than the inner diameter D2 of the opening 9 of the photoelectric conversion element 2 (D2> D4). In this way, the first conductor 13 having the connection hole 39 and the electrical insulator 15 having the connection hole 40 are overlapped and adhered to each other to be integrated, and the respective axes of the connection holes 39 and 40 are aligned. Further, the second conductor 14 is overlapped and adhered to be integrated to form a flat support 3a. In another embodiment of the present invention, the first conductor 13 having the connection hole 39.
An electric insulator 15 having a connection hole 40, and a second conductor 1
4 and 4 may be simultaneously laminated and adhered to be integrated. The thickness of the first and second conductors 13 and 14 and the electrical insulator 15 may be, for example, 60 μm. The vicinity of the opening 9 of the photoelectric conversion element 2 is fitted into the connection hole 39 and faces the connection hole 40 of the electric insulator 15. The opening 9
The vicinity may be placed on the first conductor 13 so as to face the connection hole 39.

Referring also to FIG. 1, the opening 9 of the second semiconductor layer 8 is located above the opening 9 of the photoelectric conversion element 2 in FIG.
The first connecting hole 39 on the outer peripheral surface surrounding the first connecting hole 39 of the first conductor 13 of the support body 3a or 3, that is, on the inner peripheral surface of the first connecting hole 39 or in the vicinity of the first connecting hole 39.
Is electrically connected to a portion surrounding the. Second semiconductor layer 8
Connection part 44 between the outer peripheral surface of the first conductor 13 and the first conductor 13 (see FIG. 1)
Is located on the side opposite to the first conductor 13 (upper side in FIG. 1) with respect to the peripheral edge portion 45 of the imaginary plane including the opening 9, whereby the first conductor 13 is electrically connected to the first conductor 7. The connection portion 44 is parallel to the virtual plane including the opening 9 and the center 46 of the photoelectric conversion element 2 is reliably prevented.
It exists on the opening 9 side (downward in FIG. 1) with respect to the virtual plane 47 passing through.

After that, the flat support 3a is plastically deformed by pressing to form a plurality of recesses 17 adjacent to each other. The second conductor 14 projects from the connection hole 40 of the electric insulator 15 to the upper side in FIG. 6, that is, is deformed so as to pass through the connection hole 40 and be raised to form the connection portion 21. The height H1 of the support 3 thus formed is, for example, about 1
It may be mm.

Whichever of the steps of electrically connecting the first semiconductor layer 7 and the second conductor 14 and the step of electrically connecting the second semiconductor layer 8 and the first conductor 13 is sequentially performed first. This may take place, or may also take place simultaneously.

In the recess 17 thus formed, the photoelectric conversion element 2 having the opening 9 is arranged.

In another embodiment of the present invention, the conductor 13 /
After the three-layer structure of the insulator 15 / conductor 14 is plastically deformed so that the recess 17 is formed, the above-mentioned connection holes 39,
40 may be formed on the conductor 13 and the insulator 15 by using two kinds of laser beams, respectively, to manufacture the support 3.

FIG. 8 is a simplified perspective view showing the step of disposing the photoelectric conversion element 2 in the recess 17 of the support 3.
In the above-described FIG. 7, the photoelectric conversion element 2 that has been cut while being vacuum-sucked by the suction pad 34 is conveyed into the recess 17 of the support body 3 with the opening 9 thereof facing downward. Will be placed. A plurality of, for example, 100 suction pads 34 are provided in a row. Suction pad 34
After the photoelectric conversion element 2 is placed in the recess 17 by
The support 3 is moved in the traveling direction 42 by one pitch of the concave portion 17, and the photoelectric conversion element 2 is arranged in the new concave portion 17 using the suction pad 34 in the same manner as described above. By repeating such an operation, the photoelectric conversion elements 2 are arranged in all the recesses 17. After that, the photoelectric conversion element 2 is recessed in the support member 3
Electrically connected at the bottom of.

The first semiconductor layer 7 of the photoelectric conversion element 2 is exposed at the opening 32, and the connecting portion 2 is formed at the connecting hole 40 of the second conductor 14.
Electrically connected to 1. Further, in the second semiconductor layer 8 of the photoelectric conversion element 2, the outer peripheral portion above the opening 9 is electrically connected to the portion near the connection hole 39 of the first conductor 13. These first and second conductors 13 and 14 and the second of the photoelectric conversion element 2
The respective electrical connections with the first semiconductor layers 8 and 7 may be electrically connected, for example, by eutectic using laser light, by using a conductive paste, or by using metal bumps. Thus, electrical connection can be made without using solder containing lead, which is preferable from the viewpoint of environmental protection.

FIG. 9 is a perspective view showing a state in which the combination bodies 4 and 4b having the photoelectric conversion element 2 and the support body 3 are connected. Electrical connection is made at the flat peripheral portions 61 and 61b extending outward of the combination bodies 4 and 4b.

FIG. 10 shows the combination 4 and 4 shown in FIG.
It is a disassembled sectional view of the peripheral parts 61 and 61b vicinity of b. The second conductor 14 of the other support 3b is superposed on the first conductor 13 of the support 3 of the one combination 4 and is electrically connected and fixed. In this way, the photovoltaic power generated by the photoelectric conversion element 2 for each of the plurality of supports 3 and 3b is connected in series, so that a desired high voltage can be taken out.

FIG. 11 is a simplified side view showing a state in which the combination bodies 4, 4b and 4c are electrically connected. The peripheral portion 61b of the other combination body 4b is superposed on or below the peripheral portion 61 of the adjacent one combination body 4 and electrically connected as described above. Further, the peripheral portion 61b1 on the opposite side of the peripheral portion 61b of the combined body 4b is vertically overlapped with the peripheral portion 61c of the adjacent combined body 4c to be electrically connected. In the configuration in which one peripheral portion 61b of the combination body 4b is arranged below the peripheral portion 61b of the combination body 4 as shown in FIG. 11, the other peripheral portion 61b1 is arranged in the combination body 4b.
It is located above the peripheral part 61c of c,
The steps are alternately combined and connected one above the other. Peripheral part 6
11, 61b; 61b1 and 61c may have an overlapping length L61 in the left-right direction in FIG. 11 of 1 mm, for example.

FIG. 12 is a sectional view showing an electrical connection structure of the adjacent combination bodies 4 and 4b. One combination 4
The peripheral portion 61 is raised, and the peripheral portion 61b of the other combination body 4b is formed so as to be raised. The conductor 14 in the peripheral portion 61 and the conductor 13 in the peripheral portion 61b are electrically connected.

FIG. 13 is a sectional view showing an electrically connected state of the combination bodies 4 and 4b according to another embodiment of the present invention. Although this embodiment is similar to the embodiment of FIG. 12, in particular, in this embodiment, the conductor 13 of the rising peripheral portion 61 of the combination 4 has the falling peripheral portion 61b of the combination 4b. Is electrically connected to the conductor 14. According to the connection structure shown in FIGS. 12 and 13, the recesses of the supports 3 and 3b are close to each other, and as many recesses and photoelectric conversion elements as possible can be arranged in a limited area.

FIG. 14 is a partial sectional view of a photoelectric conversion element 2 according to another embodiment of the present invention. In FIG. 14 and FIGS. 15 to 20 to be described later, each semiconductor layer is shown as a flat shape which is developed in the circumferential direction, but in reality, the semiconductor layers are arc-shaped from the radial inside to the outside, that is, in each drawing. Are sequentially stacked from the lower side to the upper side to have a spherical surface.

In FIG. 14, the n-type microcrystal (μc) Si is sequentially provided from the inside to the outside in the radial direction of the photoelectric conversion element.
Layer 63, n-type poly (Si) layer 64 / p-type a-
The structure has a double heterojunction layer of SiC layer 65 / p-type microcrystalline SiC layer 66. Table 1 shows the structure of the photoelectric conversion element having such a pn junction.

[0086]

[Table 1]

FIG. 15 is a sectional view of a photoelectric conversion element 2 according to another embodiment of the present invention. Each semiconductor layer 68, 69, 7
0 has the configuration shown in Table 1 above. In another embodiment of the present invention, in photoelectric conversion element 2 of FIG. 15, n-type single crystal or polycrystal Si may be used as semiconductor layer 68.

FIG. 16 is a sectional view of a photoelectric conversion element 2 according to another embodiment of the present invention. The specific configuration of each semiconductor layer is as shown in Table 1 above. In another embodiment of the present invention, the semiconductor layers 73 and 7 in FIG.
4 may be n-type crystal Si. In addition, the semiconductor layer 74
May be i-type microcrystalline Si.

FIG. 17 is a sectional view of a photoelectric conversion element 2 according to another embodiment of the present invention. The photoelectric conversion element 2 of FIGS. 17 to 20 has a stack structure of two junctions. In another embodiment of the present invention, the photoelectric conversion element 2 having a stack structure with three or more junctions may be used. The specific configuration of each photoelectric conversion element 2 in FIGS. 17 to 20 is as shown in Table 2.

[0090]

[Table 2]

In FIG. 17, an external cell 82 is formed outside the internal cell 81. The semiconductor layer 84 may be n-type amorphous Si, the semiconductor layer 85 may be p-type microcrystalline Si, and the semiconductor layer 87 may be microcrystalline Si.
It may be C. The pin junction layer of the semiconductor layer 86 is p-type sequentially from the radially inner side to the outer side of the photoelectric conversion element 2,
Although each of the i-type and n-type semiconductor layers may be configured to be stacked, in another embodiment of the present invention, the conductivity type of the semiconductor layers 84 and 85 of the internal cell 81 is opposite to that in FIG. The conductivity type of the semiconductor layers 86 and 87 of the external cell 82 is opposite to that shown in FIG.
Shaped semiconductor layers may be sequentially formed, which is as described above, and has a pin structure having other configurations.
The same applies to the photoelectric conversion element 2 including the bonding layer.

FIG. 18 is a sectional view of a photoelectric conversion element 2 according to another embodiment of the present invention. The inner cell 101 and the outer cell 102 have semiconductor layers 103 to 106; 107 to 11 respectively.
1 is laminated and configured.

FIG. 19 is a sectional view of a photoelectric conversion element 2 according to another embodiment of the present invention. The internal cells 112 and the external cells 113 have semiconductor layers 114 to 117;
2 are laminated and configured. Instead of the semiconductor layer 117,
It may be p-type amorphous SiO. Semiconductor layer 12
Similarly, 1 may be p-type amorphous SiO.

FIG. 20 is a sectional view of a photoelectric conversion element 2 according to still another embodiment of the present invention. The inner cell 124 and the outer cell 125 are composed of semiconductor layers 126 to 129;
134 is formed. Instead of the semiconductor layer 129, p-type amorphous SiO may be used.

The photoelectric conversion element 2 of the present invention may have a structure other than the above structure. In another embodiment of the present invention, instead of the support 3, a recess is formed by molding such as injection molding of an electrically insulating synthetic resin material such as polycarbonate, and a conductive material such as Ni is formed on the surface thereof. May be plated to form the first and second conductors to produce the support. The first and second conductors may be, for example, aluminum foil, but may be formed by Cr plating or Ag plating, and further, these metals Ni, Cr, Al, Ag, etc. are deposited or sputtered or the like. You may form. A coating layer may be formed on the first conductor, and the coating layer may be made of metal formed by plating or the like, or may be made of synthetic resin.

[0096]

According to the present invention, the material of the photoelectric conversion element,
Particularly, the amount of expensive Si used is significantly reduced, and the number of photoelectric conversion elements is further reduced to simplify the connection work process between the photoelectric conversion elements and the support, thus improving productivity,
Cost is reduced. In particular, by using the photoelectric conversion element of the present invention, it can be realized by a resource-saving and energy-saving manufacturing method. It is possible to irradiate the photoelectric conversion element with reflected light such as sunlight from the first conductor that forms the inner surface of the concave portion of the support or the coating layer thereof, and to effectively use the light. The first conductor or the coating layer thereof functions to reflect light, and is also connected to the second semiconductor layer of the photoelectric conversion element so as to guide current. Such a support has a simple structure and is excellent in productivity.

Particularly according to the present invention, the outer diameter of the photoelectric conversion element is 0.5 to 2 mmφ, preferably 0.8 to 1.2 mmφ.
And the light collection ratio x is 2 to 8, preferably 4 to 6.
It is outstanding that the amount of Si used per 1 W of generated power and the required number of photoelectric conversion elements can be drastically reduced to 1/5 to 1/10 as compared with the third prior art described above. You will be able to achieve the effect. S
By reducing the amount of i used, the photovoltaic device can be realized at low cost, and the number of photoelectric conversion elements is reduced to simplify the electrical connection work process between the photoelectric conversion elements and the support. In this way, productivity is improved, which also realizes an inexpensive photovoltaic power generation device. Therefore, it becomes possible to provide a highly reliable and highly efficient photovoltaic device.

According to the invention, the amorphous second outer layer
The optical band gap of the semiconductor layer is made wider than that of the first semiconductor layer on the center side to form a pn junction or a pin junction, whereby light is not absorbed by the second semiconductor layer of the window material on the light incident side. Thus, recombination in the surface layer can be reduced, a wide gap window effect can be achieved, and photoelectric conversion efficiency can be improved.

Further, according to the present invention, by interposing a microcrystalline (μc) semiconductor layer having high conductivity between the first semiconductor layer on the center side and the pin junction layer outside thereof, The energy conversion efficiency can be improved.

According to the present invention, it is also possible to improve the energy conversion efficiency by using the direct transition type first semiconductor layer.

According to the present invention, the photoelectric conversion element can be easily manufactured.

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view of a part of a photovoltaic device 1 according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing the overall configuration of the photovoltaic device 1.

FIG. 3 is an exploded perspective view of the photovoltaic device 1 shown in FIG.

FIG. 4 is a plan view of a part of a support body 3.

5 is a cross-sectional view showing the photoelectric conversion element 31 in a state before being mounted on the support 3 of the photoelectric conversion element 2. FIG.

FIG. 6 is a cross-sectional view for explaining a method of manufacturing a combined body 4 having the photoelectric conversion element 2 and the support body 3.

FIG. 7 is a cross-sectional view for explaining a step of cutting the spherical photoelectric conversion element 31 to form an opening 32.

8 is a simplified perspective view showing a step of disposing the photoelectric conversion element 2 in the recess 17 of the support body 3. FIG.

FIG. 9 is a perspective view showing a state in which combination bodies 4 and 4b each having the photoelectric conversion element 2 and the support body 3 are connected.

FIG. 10 is a peripheral portion 6 of the combination bodies 4 and 4b shown in FIG.
FIG. 1 is an exploded sectional view around 1,61b.

FIG. 11 is a simplified side view showing a state where the combination bodies 4, 4b, 4c are electrically connected.

FIG. 12 is a cross-sectional view showing an electrical connection structure of adjacent combinations 4 and 4b.

FIG. 13 is a cross-sectional view showing an electrically connected state of combination bodies 4 and 4b according to another embodiment of the present invention.

FIG. 14 is a partial cross-sectional view of a photoelectric conversion element 2 according to another embodiment of the present invention.

FIG. 15 is a sectional view of a photoelectric conversion element 2 according to another embodiment of the present invention.

FIG. 16 is a sectional view of a photoelectric conversion element 2 according to another embodiment of the present invention.

FIG. 17 is a sectional view of a photoelectric conversion element 2 according to another embodiment of the present invention.

FIG. 18 is a sectional view of a photoelectric conversion element 2 according to another embodiment of the present invention.

FIG. 19 is a sectional view of a photoelectric conversion element 2 according to another embodiment of the present invention.

FIG. 20 is a sectional view of a photoelectric conversion element 2 according to still another embodiment of the present invention.

[Explanation of symbols]

1 Photovoltaic device 2 Photoelectric conversion element 3,3b support 4 combination 7 First semiconductor layer 8 Second semiconductor layer 9 openings 10 part 13 First conductor 14 Second conductor 15 electrical insulator 17 recess 18 Open end

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor ▲ Taka ▲ Hideyuki Kura 2-3-3 Hata, Ikeda-shi, Osaka (56) Reference JP-A-61-124179 (JP, A) JP-A-2002-134766 ( JP, A) JP 2002-50780 (JP, A) JP 2000-22184 (JP, A) JP 9-162434 (JP, A) JP 7-297438 (JP, A) JP 7 -202244 (JP, A) JP 2001-339086 (JP, A) Schmit et al., "Recent Progress in the Dessign and Fabrication of the Surface of the Severe Epoch. , 1993, p. 1078-1081 (58) Fields investigated (Int.Cl. ⁷ , DB name) H01L 31/04-31/078

Claims (23)

(57) [Claims] 1. (a) having a substantially spherical shape, having a first semiconductor layer and a second semiconductor layer outside thereof, and
A part of the first semiconductor layer is exposed from the opening of the semiconductor layer,
The opening of the second semiconductor layer and a part of the first semiconductor layer exposed from the opening are coplanar, and a plurality of photoelectric conversion elements that output photovoltaic power from the first and second semiconductor layers. And (b) a support, which is electrically insulated between the first conductor and the second conductor via an electrical insulator, and is formed on the first conductor or on the first conductor. A plurality of recesses each having an inner surface formed by the covered coating layer are formed adjacent to each other, and a photoelectric conversion element is arranged at the bottom of each recess to form the first conductor of the recess or the coating formed on the first conductor. The photoelectric conversion element is irradiated with light reflected by the layer, the first conductor is electrically connected to the second semiconductor layer of the photoelectric conversion element, and the second conductor is electrically connected to the exposed portion of the first semiconductor layer. A photovoltaic device comprising a support to be connected. 2. The outer diameter of the photoelectric conversion element is 0.5 to 2 mm.
The photovoltaic device according to claim 1, wherein φ is φ. 3. The central angle θ1 of the opening of the second semiconductor layer.
Is 45 to 90 degrees, The photovoltaic device according to claim 1 or 2, wherein. 4. The opening end of the recess formed in the support is, for example, a honeycomb-shaped polygon, each opening end adjacent to each other is continuous, and the recess is tapered toward the bottom. The second and third semiconductor layers of the photoelectric conversion element are electrically insulated from each other at or near the bottom of the recess.
The photovoltaic device according to claim 1, wherein the photovoltaic device is electrically connected to the first conductor and the first conductor, respectively. 5. At or near the bottom of the recess of the support,
A circular first connection hole 39 is formed in the first conductor, and a circular second connection hole 40 having an axis on a straight line including the axis of the first connection hole 39 is formed in the electrical insulator. The vicinity of the opening of the photoelectric conversion element fits into the first connection hole 39, and the first outer surface and the outer peripheral surface of the opening of the second semiconductor layer
The end surface of the first connection hole 39 of the conductor or a portion near the end surface is electrically connected, and the portion of the first semiconductor layer exposed from the opening is connected to the second conductor through the second connection hole 40. The photovoltaic device according to claim 4, wherein the photovoltaic device is electrically connected. 6. The outer diameter of the photoelectric conversion element is D1, The inner diameter of the opening of the second semiconductor layer is D2, The inner diameter of the first connection hole 39 is D3, When the inner diameter of the second connection hole 40 is D4, D1> D3> D2> D4 6. The photovoltaic power generation device according to claim 5, wherein 7. When the area of the opening end of the recess of the support is S1 and the cross-sectional area including the center of the photoelectric conversion element is S2, the light collection ratio x = S1 / S2 is selected to be 2-8. The photovoltaic device according to any one of claims 1 to 6, which is characterized. 8. The photoelectric conversion element has an outer diameter of 0.5 to 2 mm.
φ, and the area of the open end of the concave portion of the support is S1 and the cross-sectional area including the center of the photoelectric conversion element is S2, the light collection ratio x = S1
/ S2 is selected from 2 to 8;
Photovoltaic device according to one of the above. 9. The outer diameter of the photoelectric conversion element is 0.8 to 1.2.
mmφ, where S1 is the area of the open end of the concave portion of the support, and S2 is the cross-sectional area including the center of the photoelectric conversion element.
/ S2 is selected from 4 to 6;
Photovoltaic device according to one of the above. 10. The photoelectric conversion element has a pn junction in which a second semiconductor layer of the other conductivity type having an optical bandgap wider than that of the first semiconductor layer is formed outside a first semiconductor layer of the one conductivity type. The photovoltaic power generation device according to claim 1, further comprising: 11. The photoelectric conversion element comprises: an amorphous intrinsic semiconductor layer outside a first semiconductor layer of one conductivity type; and an amorphous second semiconductor layer of another conductivity type having an optical bandgap wider than that of the first semiconductor layer. The photovoltaic device according to any one of claims 1 to 9, wherein the photovoltaic device is formed in this order and has a pin junction. 12. The photovoltaic device according to claim 10, wherein the first semiconductor layer is n-type Si and the second semiconductor layer is p-type amorphous SiC. 13. The photovoltaic device according to claim 12, wherein the n-type Si that is the first semiconductor layer is n-type crystalline Si or n-type microcrystalline (μc) Si. 14. The photoelectric conversion element includes an inner cell having an innermost first semiconductor layer, and an outer cell formed outside the inner cell and having an outermost second semiconductor layer, 10. Having a stack type structure.
Photovoltaic device according to one of the above. 15. The internal cell is a pn junction layer or a pin.
The photovoltaic device according to claim 14, further comprising a bonding layer, and the external cell having a pn bonding layer or a pin bonding layer. 16. The internal cell has, in order from the inside to the outside, a first semiconductor layer of one conductivity type and an amorphous and / or microcrystalline semiconductor layer of the other conductivity type, and the outer cell is from the inside to the outside. 16. The photovoltaic device according to claim 15, further comprising: an amorphous pin junction layer and an amorphous or microcrystalline second semiconductor layer having an optical bandgap wider than that of the pin junction layer. 17. The inner cell has, in order from the inside to the outside, a first semiconductor layer of one conductivity type and an amorphous and / or microcrystalline semiconductor layer of the other conductivity type, and the outer cell is from the inside to the outside. 16. The photovoltaic device according to claim 15, further comprising, in order, one conductivity type microcrystalline semiconductor layer, an amorphous intrinsic semiconductor layer, and the other conductivity type microcrystalline second semiconductor layer. 18. The inner cell has, in order from the inside to the outside, a first conductive type amorphous first semiconductor layer, an amorphous intrinsic semiconductor layer, and a second conductive type amorphous semiconductor layer. 16. The photovoltaic device according to claim 15, further comprising a conductive type microcrystalline semiconductor layer, an amorphous intrinsic semiconductor layer, and a conductive type microcrystalline second semiconductor layer in this order. 19. The inner cell has, in order from the inside to the outside, a first conductive type amorphous first semiconductor layer, a microcrystalline intrinsic semiconductor layer, and a second conductive type which is more optical than the first semiconductor layer. The external cell has, in order from the inside to the outside, a conductive type microcrystalline semiconductor layer, an amorphous intrinsic semiconductor layer, and another conductive type microcrystalline second semiconductor layer. The photovoltaic power generation device according to claim 10, comprising: 20. The photovoltaic device according to claim 1, wherein the first semiconductor layer is a direct transition type semiconductor layer. 21. The direct transition semiconductor layer is made of InAs, G
aSb, CuInSe ₂ , Cu (InGa) Se ₂ , Cu
The photovoltaic device according to claim 20, wherein the photovoltaic device is one kind selected from the group consisting of InS, GaAs, InGaP, and CdTe. 22. A plurality of supports are arranged adjacent to each other, and a peripheral portion of each support is formed so as to extend outward, and at the peripheral portion, a first support of one adjacent support is formed. The photovoltaic device according to any one of claims 1 to 21, wherein the conductor and the second conductor of the other support are overlapped and electrically connected. 23. The photovoltaic power generation device according to claim 22, wherein each of the peripheral portions has a rising portion or a falling portion, and the rising portion or the falling portion is overlapped and electrically connected. .