JPS60100483A - photovoltaic power generator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention comprises a first electrode on a soft or hard insulating substrate, a non-single crystal semiconductor doped with hydrogen or a halogen element that generates photovoltaic force, and a first electrode on the first electrode. The present invention relates to a photoelectric conversion device including a semiconductor device having two electrodes and a backflow prevention diode provided on the same substrate as the semiconductor using the same semiconductor material, and a method for manufacturing the same.

The present invention provides a semiconductor device that generates a plurality of photovoltaic forces on an insulating substrate, and further connects the output of one of the semiconductor devices so that current flows more easily than the photoelectric conversion device, and the current flows into the photoelectric conversion device. It is characterized by providing a backflow prevention diode whose electrical direction is reversed.

In order to reduce reverse leakage around the side of the semiconductor constituting the backflow prevention diode and the semiconductor that generates photovoltaic force, the present invention has a trapezoidal taper shape or a bevel shape around the side, and this structure. Semiconductor IN
During the plasma etching process, one of the electrodes is vibrated up and down, left and right, and back and forth for etching.

That is, in order to configure a photoelectric conversion device as a less expensive and highly reliable system, it is necessary to (1) first and second electrodes, (2) a semiconductor device that generates photovoltaic force, and (3) the machinery of the device. carrier or substrate for physical installation, (4) terminal for electrical connection with the outside, (5) various mechanical adhesion properties of the terminal to the substrate, (6) one of the two electrodes that transmits light. (7) the first and second electrodes and the semiconductor layer are guaranteed against mechanical strain; and (8) the semiconductor layer has high photoelectric conversion efficiency. be.

In addition, as a photoelectric conversion device, (9) the manufacturing cost of the semiconductor layer is low; (10)
A conversion device using a semiconductor layer is easy to manufacture and has a simple structure; (11) this accessory equipment is not expensive compared to a semiconductor layer; (12) the conversion device is easy to handle; (13) ) High long-term reliability is important.

However, in conventional photoelectric conversion devices, the semiconductor itself that generates photovoltaic power has a high (+Ili) value, so there has been no consideration of the system as a system including its auxiliary equipment.

In order to overcome these various requirements, the present invention makes the transparent electrode and the thin film-like non-single crystal semiconductor doped with hydrogen or a halogen element have approximately the same shape, thereby facilitating manufacturing thereof. This is a pursuit of high efficiency.

Conventionally, for example, if you try to manufacture a solar cell using the current CZ (Czochralski) slice, it costs 10 KW/year, and assuming that the silicon raw material is 80,001-77 years old, it costs 4,160 yen per unit. Furthermore, the breakdown is 74%, or 307%, in the cell section that orders photovoltaic power.
The cost of 0 yen increases. Furthermore, equipment for modularization will cost 1090111 (26%).

However, this price is 1/100 yen from 4160 yen/W.
There are many difficulties in setting the price to 40 yen/W. For example, the wafer used for the cell part has the precision of a substrate with mechanical strength. Therefore, when the cell a11 is made of a semiconductor, if the thickness of the semiconductor such as silicon used for the cell portion is 1 to 2 μm, a substrate is always required. In addition, terminals for connecting external leads from the substrate cannot be directly bonded to the semiconductor layer.

For this reason, the semiconductor layer is simply sold at 1/IO from 3070 yen/W.
Even if Q could be reduced to 30 yen/W, the result would be that it would cost 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 necessary requirements there. As a result, in the past, there was no need to assemble multiple silicon slices, and even if some solar cells were damaged, backflow prevention diodes were required to prevent the solar cells from shorting out and causing loss of power. However, in the present invention, as a system, the substrate is used as a backflow prevention guide with the same semiconductor layer as the semiconductor layer that generates photovoltaic force on the upper side, and in addition, this substrate is used to ensure mechanical distortion of the semiconductor layer. In addition to the substrate, an external lead-out end is also attached, and at least two pass lines for positive and negative are provided on this substrate, and a plurality of semiconductor layers arranged in a matrix are formed using these pass lines. The feature is that the entire system is integrated into a matrix.

Another major feature of the present invention is that it uses etching, photoetching, or selective printing for such low-cost manufacturing, and can be completed in three to four mask steps. In particular, the manufacturing process is simplified by making the semiconductor layer and the transparent electrode of one of the first or second electrodes approximately the same shape, and the manufacturing process is simplified by making the semiconductor layer and the transparent electrode of one of the first or second electrodes have approximately the same shape. Features include the provision of a lead from the electric wire 41Jλ to the board.

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

FIG. 1 shows the manufacturing process of the converter according to the present invention using longitudinal cross-sectional views.

In the drawing, (A) shows a conductive electrode (
2) is selectively formed. If a photo-etching process is used, the ■th photo I mask is used. However, selective plasma etching or printing may be used to simplify and reduce costs.

Substrate materials include methacrylic resin, epoxy resin, especially glass-epoxy composite material (commonly known as Garaebo), fluororesin,
Polycarbonate, glass, alumina and other ceramics, and solid materials were used as the hard substrate. Polyimide, polyester, silicone resin, etc. were used as the flexible and soft substrate.

For the first conductive electrode, a material with excellent adhesion to the substrate was used. For example, it may be a two-layer film in which chromium is formed on a glass substrate and aluminum is further formed on the top surface.

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

The semiconductor layer is a PN junction, a PIN junction, a PINPIN junction,
PNPN...A PN junction, a PI IN junction, etc. were prepared in such a way that a photovoltaic force could be generated by light irradiation.

The semiconductor layer used in this example is a non-single crystal semiconductor such as polycrystalline or amorphous, and its energy gap (Eg) is continuous light such as sunlight or fluorescent light, and this continuous light can be efficiently used. A W-N structure was used to ensure good photo-electrical conversion. In other words, increase Ug on the light irradiation side, that is, increase W-Eg (WIDIE Eg) from 2 to
3cv, and reduce Eg on the opposite side, that is, N-Eg(
NΔ1⇠OW IEg) was set to 0.7-1.5eν. As a semiconductor material, silicon is the main component, and carbon is contained in it.
, N+O, Ge, Sn, Pb+ In, and 5b4e were added as necessary. In addition, the semiconductor 1''A mainly used the low pressure CVa method or the glow discharge method.For these, the patent application and Japanese patent application No. 53-08 which were invented by the present inventor are
68671086868, Patent application 1986-0320701
032071 and is described in Japanese Patent Application No. 49-071738.

Thereafter, as shown in FIG. 1(C), unnecessary portions of the semiconductor layer (12) and the transparent conductive electrode (11) were removed using the same mask in a second ethoching step (2). This etching creates a transparent electrode pattern (11), <1
The semiconductor layers (12), 02') were etched into approximately the same shape as 1'). That is, 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, fluorine-based plasma esothiamant was used. That is, in a plasma etching apparatus having parallel plate type electrodes, a metal mask is used as a transparent electrode, and a portion (11) where a semiconductor layer is left, (
11') (12), installed on <12'>,
Plasma discharge was selectively applied only to the portion to be removed. At that time, plasma discharge was caused between one common electrode under the substrate and ten opposing electrodes on the substrate slightly spaced apart from the substrate transparent electrode. (Then, there is no need to use a photoresist, etc., and the transparent electrode and semiconductor layer are not mechanically damaged in any way. During this selective plasma etching, the ten opposing electrodes are placed vertically, horizontally, frontward, and backward. When it is periodically vibrated and moved at a rate of 1 to IOC/S with a width of 1 mm = I cm, the edge of the discharge becomes blurred, and as a result, the side periphery of the semiconductor layer can be made into a tapered trapezoidal shape. In addition, the angle of this taper was approximately 45° with respect to the substrate when the etch rate was the same, but when the angle was doubled to approximately 30°, it was possible to form a bevel shape.

As a result, the lead formation from the first electrode to the pass line of the substrate along the periphery of the semiconductor layer can be made extremely reliable without the possibility of disconnection. Furthermore, in the case of the reverse current prevention diode, it was possible to increase its reverse breakdown voltage and substantially expand the depletion layer at the PIN junction interface.

In Figure 1, the first lotus line (5-input photoelectric conversion device (6), another photoelectric conversion device (7) connected in series, the backflow prevention diode (8), and the second pass line (9) are shown). Two photoelectric conversion devices are connected in series to double the output voltage.

FIG. 1(D) is completed by selectively forming a conductor to become a part of the second electrode on the upper side of FIG. 1(C). In the drawing, light (10) was incident on the substrate (1) from above. A first pass line (16) provided in close proximity to the substrate
and the first electrode (13) of the photoelectric conversion device (6) are connected by a pointed portion (17). In addition, the second electrode, the counter electrode (referring to the troublesome electrode that is irradiated with light), overlaps the transparent electrode (11) and other auxiliary electrodes (30) such as a grid line pattern, a crosshatch pattern, a fishbone pattern, etc. The aim is to reduce the series resistance. This auxiliary electrode (30) for connection is provided at 20% or less, preferably about 5% of the total effective area irradiated with light. This auxiliary electrode (30) extends onto the substrate along the tapered surface around the side of the semiconductor N (12) and is connected in series to the first electrode of another conversion device (7). The counter electrode (11') of this photoelectric conversion device (7) also consists of a transparent electrode (11) and an auxiliary electrode (22).

Furthermore, this transparent electrode (11') and the auxiliary electrode overlap to constitute one electrode of the backflow prevention diode (8). The semiconductor if (12") of this diode is made of the same material as the semiconductor layer of the converter (7). This is clear from the manufacturing process shown in FIG. 1(B).
This was obtained by selectively etching the same semiconductor N(3). That is, the photoelectric conversion device (6>,
) and are provided on the same plane at the same time, and it is a feature of the present invention that no new process is required to manufacture this diode. Also, the other electrode of this diode (
13 is the base metal (
15) and Den JM (18).

Although this drawing shows an example in which two converters are connected in series, the features of the present invention can be further utilized by creating a plurality of +1M converters on the same board and connecting them in series or in parallel.

Further, in the present invention, two electrodes having different heights sandwiching a semiconductor layer are connected to each other in the same plane configuration without introducing any new process. This is important for the production of industrially very simple and low cost devices.

FIG. 2 shows another embodiment of the invention. The light passes through the substrate side and is irradiated onto the semiconductor layer from below.

In FIG. 2(A), an electrode (37) on the substrate (1), which is part of the first electrode and constitutes part of the counter electrode;
<37'>(37' was selectively formed using the first mask (2). Furthermore, a transparent electrode (4) and a semiconductor layer (3) were formed on the upper surface as in the example shown in FIG. Figure 2 (B) was obtained. In Figure 2 (C),
A second electrode (34) on its top surface.

(34'> (After 34' is formed using the second mask ■, the semiconductor layer (3) is formed using this second electrode as a mask.
was selectively etched, and then the transparent electrode (4) was further etched. Therefore, in this example as well, a self-line configuration in which the semiconductor layer and the transparent electrode had approximately the same shape could be achieved. Similarly to FIG. 1, the periphery of the semiconductor layer (3) was tapered to remove disconnections in the wiring.

FIG. 2(D) is a completed diagram of the device of the present invention. The first pass line (5) and the second pass line (9) are provided on the transparent insulating substrate (1), and the photoelectric conversion devices (6) and (7) are provided on the transparent insulating substrate (1).
) generates a photovoltaic force upon irradiation of light through the substrate. A backflow prevention diode is provided at (8). The area around the (12>, <12') side of the semiconductor is an insulator (35 l).
35'), and the lead (36
), <36') to electrically connect the photoelectric conversion devices. The counter electrode was composed of a transparent electrode (11), <11') and auxiliary electrodes (37), <37') such as a grid line pattern or a cross line Bakun. In this case, the substrate material A light-transmitting material, typically glass or transparent organic resin, was used.

Examples of the present invention will be shown below based on more specific numbers.

Specific example 1 2 is a longitudinal cross-sectional view of the photoelectric conversion device shown in FIG. 1. FIG.

Glass (JV diameter: 1.4 mm) was used as the substrate. Furthermore, chromium for a first electrode was formed on the upper surface to a thickness of 200 mm by electron beam evaporation. Etching was performed using a chromium etch solution.

Thereafter, a non-single crystal semiconductor having an l'IN junction was laminated on this upper surface. That is, N-type non-single crystal semiconductor (Pl+).

/ 5ill+ = 0.01, thickness 200 people, lig
1.7eV), type non-single crystal semiconductor (SiH4100%
, thickness 0.5p, Eg], 8eV), sawtooth silicon doped with P-type carbon (CII4: 5tllf=l
: ] BJjr / 5i14 = 0.003, thickness 100 people, Eg 2.1cV) There is. These were processed using the glow discharge method (frequency 13.5 (iMIIz).

Output LOW, pressure Q, 1. torr, growth rate 2.
1 person/second.

The substrate temperature was 210°C). Furthermore, a transparent 2〃electrode film was formed by applying tin oxide to a thickness of 700 mm by electron beam evaporation.
Formed as a person. Plasma etching was performed for the transparent electrode at a gas frequency of 13.56 MHz and an etching temperature of room temperature.

Furthermore, the auxiliary electrodes (30>, <22) shown in FIG. 11(B) were fabricated by aluminum vacuum evaporation using a stainless steel mask.

The properties obtained are as follows.

Open circuit voltage 0.7v (2 stages in series) Short circuit current 23μ Fill factor 0.5 Irradiation light White fluorescent lamp 300lx Cell area 10mm x 15111m Area of backflow prevention diode 5mm x 15mm In the above explanation, the transparent electrode is 5nOL. It was made by doping indium, antimony, or tellurium. However, the electrode on the counter electrode side may be a Schottky electrode or may be an extremely thin insulating film of 20 to 50 layers for forming a Schottky diode.

In this Schottky electrode, a metal with a large work function such as platinum is used instead of a transparent electrode, which is thin enough to allow light to pass through.
It was formed to a thickness of 25 to 100 people.

In addition, in MIS type photoelectric conversion devices, an insulating film is thin enough to allow the tunneling current of 20 to 50 people to flow (11).
A counter auxiliary electrode (22) is provided on which a grid-like or other metal electrode is placed, for example, as shown in FIG. 1(D).
Needless to say, it would be better to set it as .

In the embodiment of the present invention, at least two lotus lines were provided on only one surface of the insulating substrate. However, it goes without saying that one pass line or a portion of two pass lines may be formed by using a through hole in the insulating substrate and using the opposite or back surface thereof. However, it has the disadvantage of being expensive.

[Brief explanation of drawings]

FIG. 1 shows a longitudinal cross-sectional view of a photoelectric conversion device according to the present invention in which light irradiation is performed from above a substrate, and also shows the manufacturing process thereof. FIG. 2 shows a longitudinal cross-sectional view of a photoelectric conversion device according to the present invention in which light is irradiated from below through a substrate, and also shows the manufacturing process thereof.

Claims (1)

[Claims] 1. A plurality of photoelectric conversion devices are arranged in series on an insulating substrate, and a backflow prevention diode is connected to one of the photoelectric conversion devices in an electrically opposite direction to the current flow of the photoelectric conversion device. is a PN or PIN constituting the photoelectric conversion device
A photoelectric conversion device characterized in that it is made of the same semiconductor as a non-single-crystal semiconductor to which a hydrogen or halogen element is added, has the same junction configuration, and is provided on the same surface as the photoelectric conversion device on the substrate. .