JPS6269565A - Photoelectric conversion device - Google Patents

Abstract

PURPOSE:To prevent short circuits or leakage of electrodes on the upper and lower sides of a semiconductor, by selectively filling an insulating material only into pinholes and the like. CONSTITUTION:A light transmitting conducting film is formed on a non-light transmitting substrate. Then, a non-single crystal semiconductor layer 3, which has a P-N junction or a PIN junction is formed on the entire surface with the same film thickness in a texture structure having the flat surface or irregularities. In forming a film however, many vacant holes 6 and pinholes 6' are formed due to attachment of flakes and removal of the flakes when the film is separated. A light sensitive organic resin is applied on the semiconductor as a coat. At this time the organic resin is made to enter into the pinholes and the like sufficiently. Thereafter, the entire body is rinsed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a photoelectric conversion device using a non-single crystal semiconductor including an amorphous semiconductor that generates photovoltaic force.
When forming a non-single crystal semiconductor, holes or pinholes that are inadvertently formed in the semiconductor are filled with an insulator, and the holes or pinholes (hereinafter referred to as pinholes) where the front and back electrodes are formed are filled with an insulator. It relates to a photoelectric conversion device that prevents mutual short-circuiting or weak leakage due to the above-mentioned photoelectric conversion devices.

This invention uses a non-light-transmitting substrate, preferably in a structure in which an integrated photoelectric conversion device is provided on a substrate with an insulating film provided on a metal foil, and pinholes that may cause short-circuits or leaks between upper and lower electrodes. is characterized in that it is selectively filled with an organic resin without using any photomask.

During long-term use of this photoelectric conversion device, the material of the back electrode gradually impregnates inside the semiconductor through the pinholes, preventing short circuits between electrodes with high voltages above and below, and ultimately improving the conversion efficiency of the photoelectric conversion device. This prevents a decrease in

In the present invention, in particular, when the surface of an insulating layer has an uneven structure by seeking an optical confinement effect, the surface of a non-single crystal semiconductor can also have an uneven structure.

However, when such an uneven structure is provided, grain boundaries are formed, and many pinholes and voids are formed, especially when forming a film of a non-single crystal semiconductor. The present invention is particularly effective for such structures.

Conventionally, a photoelectric conversion device (hereinafter simply referred to as a device), that is, a device in which a plurality of elements are arranged on the same substrate and integrated or hybridized, is disclosed in, for example, Japanese Patent Application Laid-Open No. 55-4994.
Japanese Patent Application Laid-Open No. 55-1.24274 and Japanese Patent Application No. 54-90097/90098/90099 filed by the present inventor (
(filed on July 16, 1982), etc. are known.

As a conventional invention, FIG. 1 shows a vertical cross-sectional view of a photoelectric conversion device manufactured by a mask alignment method.

In the drawing, a transparent conductive film (abbreviated as CTF) (2) constituting the first electrode is selected on a transparent substrate (for example, a glass plate) (1) by an alignment process using a first metal mask. to form. Further, a semiconductor layer (3) is selectively formed in the same manner by an alignment process using a second metal mask. Further, a second electrode (4) made of aluminum is provided by an alignment process using a third metal mask.

In FIG. 1, there is a connecting part (12) between the elements (11) and (31), and in the connecting part, one side surface (16) of the CTF is covered with a semiconductor layer (3), and the other CTP is covered with a semiconductor layer (3). The semiconductor layer (3) is made not to cover the surface (14) of the semiconductor layer (3). Further, the first oxide electrode (37) and the second aluminum electrode (38) are electrically connected through a contact (14).

In this conventional example, aluminum (4) reacts with semiconductor (3), and when this integrated photoelectric conversion device is left at 150°C, its characteristics change to several tens of degrees as shown in curve (25) in Figure 3. It has deteriorated over time. Therefore, the electrode was completely unsuitable for actual outdoor use.

Therefore, in order to improve such thermal reliability, a transparent conductive film such as ITO is placed under the aluminum electrode on the back surface.
A two-layer structure is known in which ITO (indium tin oxide) is provided on a semiconductor, and aluminum is further provided on top of the ITO.

With such a structure, thermal reliability can be significantly improved because ITO can prevent aluminum from reacting with the semiconductor.

However, when forming this conductive film, this light-transmitting conductive film has a strong tendency to attract foreign particles, so if voids or pinholes are formed in the semiconductor, they may get inside the pinholes. However, a short circuit or a leak occurred between the first electrode on the lower side and the second electrode on the upper side, making it impossible to put it into practical use.

For this reason, conventionally in the formation of this non-single crystal semiconductor,
It can only be put to practical use in small-area photoelectric conversion devices, such as 1 cm x 4 cm, in which pinholes and voids are difficult to exist, and photoelectric conversion devices with large areas such as 10 cm x 10 cm or more always have voids and pinholes. Therefore, it was impossible to apply such a structure.

This is true in a structure in which a non-light-transmitting substrate having the structure of the present invention is used and light is irradiated from above with a second electrode (light (10) in FIG. 1 is incident from above). is also a serious drawback.

Particularly in this case, since the second electrode is made of only ITO, short circuits may occur due to pinholes as well.

The present invention provides extremely effective means for industrially solving these problems.

In other words, by selectively filling only these pinholes with an insulating material, the first electrode on the lower side and the second electrode on the upper side of the semiconductor can be connected even if the transparent conductive film has strong dust. The purpose of the present invention is to prevent short-circuiting or leakage even when used, and examples thereof will be shown below.

Example 1 FIG. 2 is a longitudinal sectional view showing the manufacturing process of the present invention.

In Fig. 2 (^), a non-light-transmitting substrate has an insulating surface in which an inorganic insulating film (41) such as a heat-resistant organic resin or enamel is formed on a conductive stainless steel foil (40) with a thickness of 10 to 100 μm. (A 10 cm x 10 cm substrate was used in the drawing). Furthermore, a conductive film for the lower electrode, for example, chromium (200 people) is applied to the entire upper surface.

Aluminum (1500 people) + 5nOz (200~4
00 people), aluminum (1500 people MSnJ4 (5
00 people) or a transparent conductive film whose main component is tin oxide or tin nitride added with a halogen element (1500~2
00OA,) by vacuum evaporation method, LPCVD method, plasma C
It was formed by a VD method, a spray method, or a sputtering method.

Thereafter, under the control of a microcomputer, irradiation was performed using a YAG laser processing machine (wavelength: 1.06μ or 0.53μ) to form patterning grooves (13).

The opening formed by patterning had a width of approximately 5071 cm and a length of approximately 5071 Ocm, and the width of each element (31) and (11) was 10 to 20 mm. In this way, the conductive layer (2) constituting the first electrode was cut and separated to form an opening. Thereafter, a non-single crystal semiconductor layer having a PN or PIN junction is formed on the upper surface by plasma CVD or photoCVD to a thickness of 0.2 to 1.0 μm, typically 0.5 to 0.7 μm. I let it happen. A typical example is an N-type semiconductor (200~
500 people) L-type amorphous or semi-amorphous silicon semiconductor (0.4-0.9 μ) - P-type semiconductor (S
A non-single crystal semiconductor having one NIP junction was made of a semiconductor having 1 n C1-x

or N-type semiconductor (300-1000 people) - I-type 5ix
Ge+-x (0<X<1) amorphous semiconductor-P type 5
ixC+-X semiconductor - N-type silicon semiconductor - I-type amorphous St semiconductor - P-type 5IXC+-x (0<X<1
) Tandem-type NI consisting of semiconductors (50 to 200 people)
PNIP...A NIP junction semiconductor may be used.

The non-single crystal semiconductor layer (3) was formed to have a uniform thickness over the entire surface and to have a flat or uneven texture structure.

However, this semiconductor has flakes (snowflakes) during film formation.
Pores (6
), many pinholes (6゛) are present unintentionally. The insulator was selectively filled in 10 fields of view using a microscope with a magnification of 1.00. The work is shown below.

After forming the semiconductor shown in FIG. 2 (8), this semiconductor was coated with a photosensitive organic resin. At this time, care was taken to ensure that the organic resin sufficiently impregnated into the pinholes and the like. As the photosensitive organic resin, a positive type photoresist such as 0FPR-800 sold by Tokyo Ohka Co., Ltd. was used.

Apply this photosensitive organic resin to the entire surface of the semiconductor using a spinner.
It is formed to a thickness of 0.1 to 5 μm using a coater or spray method. At this time, it is important to reduce the amount of photosensitive organic resin formed on the back side of the semiconductor so that pinholes and the like can be more fully filled. For example, when using a spinner, resist the resist at 50Orpm for 5 seconds and 200Orpm.
Coating was carried out under conditions of 30 seconds at pm. Further, the applied organic resin film was prebaked (85° C., 40 hours). Furthermore, as a development process, ultraviolet light (wavelength 300-400 nm) (17) is irradiated from the resist side to immobilize the organic resin filled in the pinholes etc. of this photosensitive organic resin, and further to fix the organic resin filled in the pinholes etc. It was exposed to light in order to unimmobilize the organic resin. This condition is 0FPR-800
In the case of using (Q), ultraviolet light was applied at 6 mW/cm'' for 5 seconds, and a predetermined development process was performed.

Furthermore, the whole was rinsed (with pure water for 10 minutes) by a known method. Then there is a pinhole (6).

Non-immobilized organic resin other than the organic resin film fixed within (6゛) can be dissolved away. That is, all the organic resin on the semiconductor (3) can be removed. Furthermore, post-baking (150°C for 1 hour) was performed to chemically stabilize the organic resins (7) and (7') filled inside the exposed pinholes. Then, as shown in FIG. 2(B), only the pinholes (6) and (6') can be selectively filled with the organic resin insulators (7) and (7').

Thus, as shown in Figure 2 (B), the pinhole (6)
, organic resin insulator (
7).

(7°) can be filled.

The upper surface of this insulator can be filled so as to be approximately coincident with the upper surface of the semiconductor or to a lesser extent (due to volume contraction during post-curing, etc.).

Furthermore, as a next step, as shown in FIG. 2(B), a second groove (18) was formed to the left of the first groove (13) by a second laser scribing process. This laser scribing was performed by irradiating the substrate (1) from above.

Thus, the side surfaces (8) and (9) of the first electrode were exposed by forming the second open groove (18). The side surface (9) of this second open groove may be on the left side of the side surface (16) of the first electrode (37'); as an extreme example, as shown in the drawing, the side surface (9) of the first electrode (37') ). Furthermore, this patterning can be carried out without exposing the side surface (8) as shown in FIG. 1(B) or without patterning the conductive film (2). (such as) may be exposed.

Thereafter, a second electrode was formed using a transparent conductive film using a metal mask. That is, this second electrode is a transparent conductive film (
23) for 300 to 1400 people, such as ITO (indium tin oxide), rngo3 (indium oxide).

It was formed from 5nO2 (tin oxide) and ITN (indium tin nitride) (a mixture of indium nitride and tin nitride).

These are designed to prevent a conductive film from being formed in the open groove (20).
A metal mask is placed on the semiconductor shown in FIG. 2 (R) in advance, and then a transparent conductive layer is formed using a sputtering method, an electron beam evaporation method, or a plasma CVD method at a temperature of 300° C. or less without deteriorating the semiconductor layer. A film was formed.

Thus, as shown in FIG. 2(C), a plurality of elements (3
We were able to create a photoelectric conversion device in which 1) and (11) were connected in series at the connecting part (12).

FIG. 2(D) shows an attempt to further complete the present invention as a photoelectric conversion device. That is, polyimide,
Organic resins such as polyamide, kapton or epoxy (2
2) was filled.

Thus, when the irradiation light (lO) is irradiated with 8 Ml (100111 W/cmz) using a photoelectric conversion device panel integrated with a substrate (10 cll x locm) as in this example, the open circuit voltage is 11.30 V and the fill factor is 0. 626 Short circuit current 79.4 mA ゛ Current density 17.31 mA/am” Conversion efficiency
It was possible to have an output of 8.16χ.

However, if the exact same steps are used but only the step of filling the organic resin of the present invention shown in FIG. 2(B) is omitted, only the following conversion efficiency can be obtained. That is, open circuit voltage 6.
54V Fill factor: 0.368 Short circuit current: 75.69mA Conversion efficiency: 3.48χ From these results, it can be seen how effective it is to have a structure in which the pinholes of the present invention are filled with an organic resin.

Figure 3 shows the reliability test of the present invention and the conventional example.
, conditions of high temperature storage in the atmosphere).

The curve (25) in FIG. 3 is the conventionally known configuration shown in FIG. 1, in which the back electrode has a structure in which aluminum is closely attached to the semiconductor; The connection portion is of the tin oxide-aluminum contact type.

In this structure, aluminum oxide is formed at the contact portion, and the aluminum itself also reacts with the N-type semiconductor. As a result, it drops to less than 50% of its initial value in just a few hours.

Further, the curve (26) is the reliability characteristic of the photoelectric conversion device having the structure of Example 1. This is a case where an ITO film is used as the second electrode on the semiconductor. In this case, the contact was an oxide (tin oxide)-oxide (ITO) contact, and the reliability of the contact portion was excellent.

More importantly, by filling the binhole 5 of the present invention with an insulating material, there is little variation among samples of photoelectric conversion devices in the initial state, and the manufacturing yield is high. For example, even if 10 pieces of 10clIIO are made, the σ (variance) can be obtained as 0.27.

The organic resin mold (22) is covered to fix the extraction electrode (5), and this panel is further
X 20cm, 60cm X 40cm or 120
cm x 40cm packaged with 6 pieces, 2 pieces or 1 piece aluminum sash frame, 120cm x 40cm
It is possible to provide a panel of the Mongolian NEDO standard.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a conventional photoelectric conversion device. FIG. 2 is a longitudinal sectional view showing the manufacturing process of the photoelectric conversion device of the present invention. FIG. 3 shows an example of reliability characteristics of photoelectric conversion devices of the present invention and a conventional example.

Claims (1)

[Scope of Claims] 1. A first electrode on an insulating surface of a non-light-transmitting substrate, and a non-single-crystal semiconductor that generates a photovoltaic force on the electrode, and formed on the non-single-crystal semiconductor. The voids or pinholes are filled with an organic resin insulator, and a transparent second electrode is provided on the non-single crystal semiconductor to cover the filled insulator. Photoelectric conversion device. 2. A photoelectric conversion device according to claim 1, characterized in that a non-single crystal semiconductor is provided on a non-light-transmitting substrate having an insulating layer on a metal foil. 3. A photoelectric conversion device according to claim 2, wherein the surface of the insulating layer has an uneven structure, and the surface of the non-single crystal semiconductor also has an uneven structure.