JPS5976483A - Semiconductor device for photoelectric conversion - Google Patents

Abstract

PURPOSE:To reduce the cost and enhance the area efficiency by a method wherein a plurality of photoelectric converters which generate photovoltage are provided in series connection on one insulating substrate, and a reflux blocking diode is formed by the same process as that. CONSTITUTION:Conductive electrodes 2 used for the photoelectric converters 6 and 7 and the reflux preventing diode 8 are selectively formed on the insulation substrate 1 composed of resin, etc., and a semiconductor layer 3 and the second electrode material 4 composed of a clear conductive electrode are laminated and adhered over the entire surface including those. At this time, a polycrystalline or an amorphous non-single crystal semiconductor is used for the semiconductor layer 3, thus making it so as to generate a photovoltage by light irradiation, including a P-N-N junction. Next, the unnecessary layer 3 and material 4 except the regions for forming the devices 6 and 7 and the diode 8 are removed by etching, the devices 6 and 7 are connected each other by means of a conductor 30, and conductors 22 and 14 serving as electrodes are mounted on the device 7 and the diode 8.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a photoelectric conversion semiconductor device that is low in cost and highly reliable.

The present invention includes a first electrode provided on a substrate having an insulating surface (hereinafter simply referred to as an insulating substrate), a semiconductor layer on the electrode that generates a photovoltaic force, and a second electrode on the semiconductor layer. The present invention relates to a semiconductor device that generates a photovoltaic force, and a method for manufacturing a photoelectric conversion device semiconductor device, in which backflow prevention guides are formed at different positions on the same insulating substrate in the same process as the photoelectric conversion device.

This invention is achieved by providing a plurality of photoelectric conversion devices that generate photovoltaic forces connected in series on one insulating substrate, and manufacturing a backflow prevention diode in the same manufacturing process as the production of this photoelectric conversion device. The purpose of the present invention is to reduce manufacturing costs and improve area efficiency by combining photoelectric conversion semiconductor devices for generating photovoltaic power in the form of thin films. As a result, a comprehensive photoelectric conversion system can be produced in large quantities at low cost.

The present invention aims to complete a photoelectric conversion semiconductor device as a less expensive and highly reliable system. That is, in general, a photoelectric conversion semiconductor device includes: [1] first and second electrodes, [2] a semiconductor layer that generates photovoltaic force, [3] a carrier or substrate for mechanical installation of the device, [4] Terminals (5) (4) for electrical communication with the outside
[3] various mechanical adhesion of the terminal to the substrate; (6) at least one of the two N poles in [1] is optically transparent; [7] the first and second electrodes and the semiconductor; It is pointed out that it is necessary that the layer is guaranteed against mechanical strain; and [8] that the semiconductor layer has high photoelectric conversion efficiency.

In addition, sufficient conditions for a photoelectric conversion semiconductor device include: (1) the manufacturing cost of the semiconductor layer is low; (2) (
1) The conversion device using the semiconductor layer is easy to manufacture and has a simple structure, [3] The cost of this accessory equipment is not expensive compared to the semiconductor layer, and [4] The conversion device is easy to handle. [5] High long-term reliability is important.

However, conventional photoelectric conversion devices use a single crystal semiconductor wafer as a semiconductor layer for generating photovoltaic force. Furthermore, because these wafers are expensive, no consideration was given to the wafers as a system, including all the equipment involved.

The present invention considers the entire system and relates to a method for manufacturing a photoelectric conversion semiconductor device that satisfies many of these necessary and sufficient conditions.

Conventionally, for example, when trying to make a solar cell using a CZ' (Czochralski~) slice (wafer), it required 10KW.
/year, and assuming that the silicon raw material is from 80001-77, it costs 416 yen per IW.

Moreover, the breakdown is 74% in the cell part that generates photovoltaic force.
%, it costs 5,307 yen. Additionally, 109 yen (26%) will be charged for other modular equipment. However, this price is 1/100th of 4 yen/W from 416 yen/W.
There are many difficulties in achieving W.

For example, the wafer used for the cell portion has the characteristics of a substrate with mechanical strength. Therefore, it is effective to try to reduce the cost by making the cell part from a semiconductor thin film.

However, if the thickness of a semiconductor such as silicon used for the cell portion is simply set to 0.1 to 2 μm, a substrate is always required. In addition, terminals that extend external lead electrodes from the substrate cannot be directly bonded to the semiconductor layer.

For this reason, the semiconductor layer is simply 307 yen/W, which is 1/3
Even if it were possible to reduce the cost to yen/W, it turned out that it would end up costing more than ever to make it modular.

In order to eliminate such drawbacks, the present invention looked at conventional solar cells in a larger system and considered the requirements necessarily necessary therein.

As a result, the power generation system requires the collection of multiple silicon slices, and even if some of the solar cells are damaged, there is a continuous current prevention guide that prevents the solar cells from shorting out and causing a loss of power. Needed.

Accordingly, the present invention uses an insulating substrate as such a system, and provides a composite photoelectric conversion device for generating photovoltaic force on the insulating substrate. Furthermore, a backflow prevention diode was fabricated using the same structure and manufacturing process as this photoelectric conversion device. That is, since the present invention uses the same manufacturing process, it is an object of the present invention to manufacture a photoelectric conversion device that can be manufactured at exactly the same manufacturing cost even if the backflow prevention diodes are manufactured on the same insulating substrate.

In addition, an external drawer end is attached to this board, and at least two lotus lines for output are provided on this board,
Using this pass line, a plurality of semiconductor layers are formed into a matrix 71. It is characterized by integrating the entire system into a single unit.

Furthermore, the present invention aims at such low-cost mass production by etching (removal) or photo-etching in the manufacturing process.
Another major feature is that it can be completed in 3 to 4 times using etching or selective printing.

In the removal (etching) process, the semiconductor layer and the first
Alternatively, by making one of the second electrodes have approximately the same shape, the manufacturing process can be omitted, and the lead from the electrode provided above the substrate surface along the side surface of the semiconductor layer to the substrate can be omitted. It has the following characteristics:

The present invention will be explained below with reference to the drawings.

FIG. 1 shows the manufacturing process of the photoelectric conversion device of the present invention by showing vertical cross-sectional views of the photoelectric conversion semiconductor device of the present invention in the order of steps.

In the drawing, (A) shows conductive electrodes (2) selectively formed on an insulating substrate (1). In this way, the photoelectric conversion devices (6), (7) and the backflow prevention diode (8) were fabricated at the same time as the first electrode for forming them on the same insulating substrate (1). In this manufacturing process, if a photo-etching process is used, the [1] mask is used. However, selective plasma etching or printing methods may be used to simplify and reduce costs.

As the insulating substrate material, methacrylic resin, evoki resin, especially glass-epoxy composite material (commonly known as GALA EBO), fluorine resin, polycarbonate, glass, alumina and other ceramics, chinaware, etc. were used as the hard substrate. As the flexible and soft substrate, polyimide, polyester, silicone resin, etc. were used.

For the first conductive electrode (2), a material with excellent adhesion to the substrate was used. For example, chromium was formed on a glass substrate.

In FIG. 1(B), this upper surface is coated with a semiconductor layer (3) and a second electrode material (4) consisting of a transparent conductive electrode.

The semiconductor layer was fabricated so that a photovoltaic force could be generated by irradiation with light such as a PIN junction, PI junction, or ILN junction. A non-single crystal semiconductor such as polycrystalline or amorphous semiconductor was used for the semiconductor layer.

In the present invention, in order to enable mass production at low cost and to simplify the manufacturing process, a thin film type non-single crystal semiconductor is used, and its energy gap (Eg) is similar to that of sunlight or fluorescent light. In order to provide continuous light and efficiently perform photo-electrical conversion of this continuous light, the W-Nl structure was used. In other words, the light irradiation side is EIl! that is, W −E
g (WIDE Eg) (7) Reduce Eg on the opposite side to 2 to 3 eV, that is, N-Eg (NALLOW
Hg) 0.7 to 1.8 eν. As a semiconductor material, silicon is the main component, and C, O, and N are added to it to increase its energy gap, and if necessary, Ge, Sn, and Pb are added to decrease the energy gap. I let it happen.

Te, In, and Sb were added to improve the electrical conductivity near the electrode interface. For the semiconductor layer, a low pressure CVD method or a gas phase method in which electrical energy is applied under reduced pressure, namely a glow discharge method was mainly used. The semiconductor layer was formed using a method of gradually forming a film from the bottom. Regarding these, patent application and patent application No. 53-08686 which are inventions of the present inventor
71086868, patent application 1977-0320701032
071, and is described in Japanese Patent Application No. 49-071738.

A second electrode (
4) were formed by laminating them.

After this, as shown in FIG. 1(C), a second etching process [2] is performed to remove unnecessary parts of the semiconductor other than the areas where the photoelectric conversion devices (6), (7) and the backflow prevention diode (8) are to be formed. The layer and transparent conductive electrode were removed. At this time, the semiconductor N
(12) and (12') are removed. This is because the semiconductor layer was etched using the transparent electrode as a mask. Further, this semiconductor layer has a trapezoidal shape, and the periphery of the trapezoid is tapered etched. Actually, a known fluorine-based plasma etching method was used. In the plasma etching method, the electrode is a transparent electrode and the remaining semiconductor layer is the remaining part (n).
,<x? >, o2>, (1zo) was selectively plasma discharged. Furthermore, at that time, a common electrode was provided under the substrate, and ten opposing electrodes were arranged in a pattern on the substrate at a slight distance from the substrate transparent electrode, and plasma discharge was caused only under this electrode. .

In this way, there is no need to use photoresist, etc.
Furthermore, since the transparent electrode and the semiconductor layer do not come into contact with each other, they are not mechanically damaged by IJ.

In FIG. 1(C), a first pass line (5), a photoelectric conversion device W (6), another photoelectric conversion device !ff1 (7), and a backflow prevention diode (8) are connected in series.

Scrape with the second lotus line (9). Photoelectric conversion device (6>,
(7) is a case of two devices, which are connected in series to double the output voltage. Furthermore, this photoelectric conversion device (7)
The second electrode (11) is connected to one electrode of the anti-backflow diode (8) by the same manufacturing process.

Figure 1 (D) shows conductors (30), <22), <14) that will become part of the second electrode on the upper side of Figure 1 (C) selectively placed on the semiconductor above the first electrode. It was completed by forming the This electrode (11) is also provided with a shield to prevent the irradiation light from above from being transmitted to the semiconductor N (12) of the backflow prevention diode. Drawing G (6) and 4, light (
10) is incident from above, and the first pass line (]6) is provided in close proximity to the substrate G.
6) is connected to the first electrode through four leads (=17). In addition, the second electrode is an electrode (11) consisting of a transparent conductor (11), a grid line pattern, a crosshatch pattern, and a lattice line pattern. Colored metal electrodes (30) of turns etc.
(established by) This metal base, lead, etc. is used for photoelectric conversion, and the optical power <p, @4 dimensions, preferably 20% or less of the total effective area, and changes rapidly (5%). This electrode (30) is +31 of the semiconductor layer (12).
The electrode (of color) is connected in series to the first electrode of the electric conversion device (7). The second electrode of this device (7) also consists of a transparent electrode (11) and a metal electrode (22).

Furthermore, the transparent electrode and the metal electrode (14) are stacked one on top of the other, and the metal electrode has a light-shielding structure so that the irradiated light does not reach the inside of the semiconductor, creating a so-called backflow prevention diode (
8) constitutes the other second electrode.

The semiconductor layer (12) of this backflow prevention diode is the same as the semiconductor layer of the photoelectric conversion device (7), and it is shown in FIG.
), the electrode (2) on the substrate at the same time.
-J: is obtained by edging (removing) the same semiconductor layer (3) formed in .

That is, it is possible to form a first electrode, a semiconductor layer, and a second electrode by laminating them on the same insulating substrate, and to manufacture a photoelectric conversion device and a backflow prevention diode using the same manufacturing process using the same material. Became. Therefore, when the photoelectric conversion device is damaged or short-circuited, a backflow prevention diode (8) is installed on the same insulating substrate at the same time as the photoelectric conversion devices (6) and (7), which prevents the entire system from becoming inoperable. A feature of the present invention is that it is provided on a flat surface and does not require any new process for manufacturing this diode.

This drawing shows an example in which two photoelectric conversion devices are connected in series, but as shown in FIG. We are making even more use of it. In particular, the present invention has two electrodes with different heights sandwiching a semiconductor layer between them.
1) Extends upward to ensure mechanical strength. The ability to connect without introducing any new process for this purpose is important for manufacturing extremely simple and low-cost equipment industrially.

FIG. 2 shows another embodiment of the invention. The numbers of the substrate or each part are the same as in the embodiment of FIG.

This example is also a case where light is irradiated from above.

In FIG. 1, the leads from the counter electrodes (II) and (11) were in close contact with the side surfaces of the semiconductor layers (12>, <12') and extended onto the substrate. That is, in this case, (28>, (2B') in FIG. 1(C) is sufficiently long compared to the thickness of the semiconductor layer, and even if the resistance is substantially shorted due to metal around the side, the current It is necessary that the thickness of the semiconductor layer is long enough to prevent it from flowing.In other words, if the thickness of the semiconductor layer is 1 to 3μ, it is necessary to have a thickness of 3mm to 3cm, which is 10-to times that thickness.For this reason, this area is not wasted. In order to avoid this, the periphery of the side of the semiconductor layer having the joint portion was covered with an insulator, although it added one step.

In FIG. 2, between this lead and the semiconductor layer 6. m
Interpose the absolute luxury (29), <33), <33'),
It is electrically insulated and stable. Since the junction portion of the semiconductor layer is covered with an insulating material, reliability is improved, but this method has the disadvantage that a new step of selectively coating the insulating material is added. This insulator is a converter (6>,
<7) also constitutes the effect of a mechanical protective film (2o).

FIG. 3 shows another aspect of the invention.

Light passes through the transparent insulating substrate (eg, glass) and is irradiated onto the semiconductor layer from below. In the drawings, FIG. 3(A) shows an electrode formed on a substrate (1), which is a first electrode and constitutes a part of a counter electrode. Furthermore, as a subsequent step, a transparent conductive film (4) and a semiconductor layer (3) were formed as shown in FIG. 3(B). Furthermore, Figure 3 (C
), a second voltage +fi is applied on the semiconductor layer (3).
(34>, 34'), (34"5 was formed, the semiconductor layer (3) was selectively removed using this second electrode as a mask, and the transparent electrode (4) was further etched (removed). Therefore, in this invention as well, a self-line configuration in which the semiconductor layer and the transparent electrode have approximately the same shape could be achieved.

FIG. 3(D) is a completed diagram of the device of the present invention.

The first lotus line (5) and the second lotus line (9) are provided on the insulating group Fi, (1), and the photoelectric conversion device (6),
(7) generates a photovoltaic force upon light irradiation through the substrate. A backflow prevention guide is provided at (8). An insulator (35) is placed around the (12) and (12') sides of the semiconductor layer.
), (35'), and by placing the leads (36), (36') closely on this insulator,
Two photoelectric conversion devices are electrically connected in series. The counter electrode is a transparent electrode ('l 1 >, <11') and a metal electrode ('l 1 >, <11') with a grid line pattern, a cross line pattern, etc.
37>, (37), (37), and <37). Further, the electrode on the light irradiation surface side of the backflow prevention diode (8) blocks irradiation light with a metal (37).

In FIG. 3, the insulating substrate material is optically transparent + AJA, typically glass or transparent organic resin.

FIG. 4 shows the relationship between the lotus lines and external connection terminals in the present invention.

Figure 4 (Δ) shows a lotus line (15) on the substrate (1) and a metal lead (18) on the top surface of the lotus line (15).
Bonding (4
0) Lk also has notes. Figure 4 (B) C) is 0.2~
Solder 1mm soi-1-(,+1) (47)
In particular, in Figure 4 (B), only a part of the resin coating (42) is selectively removed and the wire (41) is removed.
is ultrasonic bonded.

FIG. 4(E) shows a hole made in the substrate, Pol l-(44) is fixed thereon, and two nanoJs (45) and (45') are used to extract larger power to the outside.

The converter section is protected by (42).

FIG. 5(A) shows four photoelectric conversion devices arranged in parallel, and the negative side has a size of 10 to 100 cm.

Further, FIG. 5(B) shows two devices arranged in series and further arranged in two series in parallel.

FIG. 5(B) corresponds to FIG. 1 or 3, but has two pass lines (50), <51), which are provided on the substrate (59).

The backflow prevention diodes are numbered (53), <53>, and (54). ) was also effective for system protection.

Also, as is clear from Figures 1 to 5, this diode is 1/1 of the photoelectric conversion device when its current density is considered.
0 or less is sufficient. The area occupied on the board is 1150 ~
1/100 was sufficient.

In the above description, the transparent electrode was prepared by doping 5 nOy with insulin, antimony, or tellurium.

In the embodiments of the present invention, two lotus lines were installed only on one surface of the insulating substrate. However, one pass line or a part of two lotus lines was formed by using the insulating substrate as a through ball. Needless to say, it may be formed using the opposite side or the back side.However, in that case, there is a disadvantage that the cost becomes high.The present invention provides that one of the two pass lines is formed so that one of the two pass lines is located closer to the semiconductor layer than the surface of the substrate. It is characterized by being electrically connected by a second electrode located at a distant position, and the connection does not require any special process and can be treated as if it were the first electrode. has its characteristics.

As is clear from the above explanation, the present invention is applicable to show 1-1 when one photoelectric conversion device or one series is damaged or the like.
In order to prevent the potential from decreasing and the current to flow backwards when the photoelectric conversion device is fabricated, a backflow prevention diode is fabricated on the same insulating substrate without adding any new process to the photoelectric conversion device. It was extremely effective to make this possible, lower prices, and increase mass production.

Furthermore, according to the method of the present invention, when light is not irradiated to this system at night etc., the potential of the external connection terminals (56) and (57), which are the output terminals, is higher than that of the photoelectric conversion device or system. Although there are cases where the water becomes too high and causes backflow, it has become possible to prevent this situation.

In order to further complement the present invention, examples thereof will be described below.

Example 1 FIG. 1 is a longitudinal sectional view of an embodiment of the present invention.

That is, a glass substrate was used as the substrate (1) having an insulating surface. 0.3μ of chromium was applied to this upper surface by sputtering.
It was formed to a thickness of . After this, selective etching was performed on this metal film.

Furthermore, a non-single crystal semiconductor layer having a PIN junction was formed on the upper surface using a glow discharge method. At this time, the first chromium
A P-type silicon semiconductor layer of 300 layers was placed in close contact with the electrode of
A type silicon semiconductor layer having a thickness of 0.5 μm and an N type semiconductor layer made of silicon carbide having a thickness of about 10% carbon added to silicon were gradually laminated to a thickness of 200 μm.

As a result, compared to the optical energy band lJ of the internal I-type semiconductor layer of 1.6 eν, the optical energy band on the light irradiation surface side is 2. A t-N structure with a wide energy hand of OeV was constructed.

Further, on this N-type semiconductor layer, a transparent conductive film (4) was formed by doping SnO2 with indium (indium oxide/tin oxide mixture) by electron beam evaporation.

Thereafter, the transparent conductive film (4) and the semiconductor (3) were subjected to plasma etching to form the structure shown in FIG. 1(C).

Thereafter, aluminum was laminated to a thickness of 0.5 μm using a vacuum evaporation method, and electrodes and leads were further formed using a known etching method.

In this way, the first photoelectric conversion device (6) and the second photoelectric conversion device (7) connected in series were provided on the same glass insulating substrate.

In such a structure, the conversion efficiency is 2.5% (open circuit voltage 1.4V, fill factor 53%, short circuit current 3.4m8).
) was able to be obtained.

Furthermore, the backflow prevention diode that was created at the same time did not allow current to flow back into the photoelectric conversion device even when a voltage of 1.5V was applied from the outside, making it possible to integrate it into a system.

This open circuit voltage is 1.4ν, which is about twice the conventional 0.73ν.
The fact that we were able to obtain this proved that the structure of the present invention is excellent for obtaining a high voltage, and that it is also possible to make a reverse current prevention diode at the same time.

Example 2 This example was carried out according to FIG.

That is, the chromium lead (2) is placed on the glass substrate (1).
．． It was provided to a thickness of 5μ and subjected to known selective etching (1). Furthermore, on this upper surface, a transparent electrode (4), a semiconductor layer (
3) was formed in the same manner as in Example 1. That is, the transparent conductive film was prepared using 5 nOz and 1'-doped with antimony.

Furthermore, non-single crystal semiconductors are P (100 people) I (0,
5μ) N (200 people) structure, and a large Eg was obtained by adding carbon to silicon as a P-type semiconductor. For the first layer, silicon was used. In this way, the light irradiation area (substrate side) is widened.
A semiconductor layer having a W-N structure having the structure of g was fabricated by a glow discharge method.

Furthermore, after making a second electrode (34) from an alkaline earth metal, this electrode is masked and the semiconductor layer and transparent electrode (4) are removed, so that the surfaces of these semiconductor layers are formed into approximately the same shape. Ta.

After that, as shown in FIG. 2(D), the polyimide resin insulator (thread) is coated, and each photoelectric conversion device is connected in series using a selected etching method.
(36) was prepared.

In this way, a plurality of photoelectric conversion devices could be connected in series on an insulating substrate having a W-N structure.

The characteristics obtained with this photoelectric conversion device are a conversion efficiency of 2.7%,
Open voltage], 35V, fill factor 51%, short circuit current 3.
It was 9mA/ca. In this characteristic, the voltage is about 2
I was able to double it.

Furthermore, the backflow prevention diode made at the same time was
．． It was found that even when 5ν was added, no backflow occurred within the photoelectric conversion device, and the system could be insulated.

[Brief explanation of the drawing]

FIGS. 1 and 2 are longitudinal sectional views of a photoelectric conversion semiconductor device according to the present invention in which light irradiation is performed from above, and also show the manufacturing process thereof. FIG. 3 shows a longitudinal cross-sectional view of a photoelectric conversion semiconductor device according to the present invention in which light is irradiated from below through a substrate, and also shows the manufacturing process thereof. FIG. 4 is an embodiment showing the relationship between the substrate, pass lines, and external connection terminals of the present invention. FIG. 5 shows a photoelectric conversion semiconductor device when used as a system. (C) (D) Must (E) Certain five mouths

Claims (1)

[Claims] (2) A plurality of first electrodes for configuring a semiconductor device that generates photovoltaic force provided on a substrate having an insulating surface, and another first electrode for configuring a backflow prevention diode. a non-single-crystal semiconductor layer for generating a photovoltaic force on the first electrode, and a diode for preventing backflow on the other first electrode. layers are made of the same semiconductor material, and a plurality of second electrodes are provided above the first electrode on the semiconductor, and another second electrode is provided above the other first electrode. . A photoelectric conversion semiconductor device, characterized in that the plurality of photovoltaic power generation photoelectric conversion devices and the backflow prevention diode are connected on the same substrate. 2. The photoelectric conversion semiconductor device according to claim 1, wherein the electrode on the light irradiation surface side of the backflow prevention diode has a light shielding structure to prevent irradiation light from entering the semiconductor.