JPS59144180A - Photoelectric converter - Google Patents

Abstract

PURPOSE:To improve the reliability by forming electrodes made of light transmission conductive films on both side surfaces of a non-single crystal semiconductor having P-N or PIN junction. CONSTITUTION:An oxidized indium layer having oxidized tin is formed on a light transmission substrate 1, and oxidized tin is further formed to form a light transmission electrode 2. A non-single crystal semiconductor 3 having a P-N or PIN junction is laminated thereon, an oxidized indium layer having oxidized tin is further formed to form a light transmission electrode 4. A heat fusible filler 7 having light transmission such as polyvinyl butyral is formed thereon, and a light transmission substrate 8 is further formed thereon. Accordingly, since aluminum is not used in the electrode, the aluminum is not diffused in the semiconductor, thereby improving the reliability. Further, a light of a wavelength larger than 600nm diffused to the back surface side from the electrode 4 is dispersed externally from the substrate 8, thereby preventing the temperature rise therein.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a photoelectric conversion device using a non-single-crystal semiconductor, and particularly to a semiconductor device that requires high efficiency and high reliability, and a method for manufacturing the same.

This invention comprises a translucent SI insulating substrate, a first electrode having a first translucent conductive film (hereinafter simply referred to as CTFI) on this substrate, and a photovoltaic force generated by irradiating light onto this electrode. at least one that generates.

A non-single crystal semiconductor having a PN or PIN junction, and a second transparent conductive film on the semiconductor (hereinafter simply referred to as CrF2)
It has a structure in which a photoelectric conversion element (hereinafter simply referred to as PvC or element) provided by a second electrode made of the following is provided, and this is formed into a panel to form a photoelectric conversion device. In the present invention, the second electrode (also referred to as the back electrode) of the photoelectric conversion element is made of CrF2.
By doing so, 600n of irradiation light such as sunlight
It has an electrode structure that allows long wavelength light of m or more to be emitted backward from the second electrode.

That is, the present invention provides first and second
Both electrodes are not metal but tin oxide indium oxide.
CTF made of oxides such as aluminum, indium oxide, tin oxide, etc.
This prevents the conventionally known electrode-constituting metal, generally aluminum, from migrating into semiconductors and reducing reliability in high-temperature storage tests at temperatures above 150°C. The purpose is to

Further, by using CTF as both the first and second electrodes of the present invention, it is possible to employ a laser scribing method (simply referred to as LS) when forming a composite integrated structure. Another feature is that it can reduce the area, that is, improve the effective conversion efficiency.

In addition, the present invention further provides 6
It is characterized in that long-wavelength light with a wavelength of 00 nm or more is provided on the back surface and is emitted to the outside from the second light-transmitting insulating substrate.

By doing so, it is possible to prevent the temperature of the photoelectric conversion device itself from increasing, and thus to prevent a decrease in efficiency.

Furthermore, in addition to radiating long-wavelength light including infrared light to the outside, it becomes possible to provide a solar water heater adjacent to this second electrode.

That is, the present invention performs photoelectric conversion using short wavelength light and photothermal conversion using long wavelength light, and by integrating them and installing them on the roof of a general house, the overall conversion efficiency of sunlight can be extremely high. It has other characteristics of being able to.

In other words, utility model registration application 53-83 filed by the inventor
838 (filed on June 19, 1978) "Solar Cell", by making the reinforced glass part on the front of a solar water heater into a laminated glass structure containing a photoelectric conversion device, solar energy can be generated. It also has the feature of increasing the overall utilization efficiency of.

The present invention has a structure in which the front and back surfaces of the device are sandwiched with an inorganic material made of glass, and a plurality of devices are integrated on a single substrate, thereby achieving high quality and high reliability. I was able to force it.

In addition, since no metal material is used for the electrodes, it is possible to
In LS using high temperatures, abnormal diffusion does not occur at the same time as scribing, and high reliability can be achieved even in the manufacturing process of multiple integration.

Furthermore, unlike conventional mask methods that use vapor deposition masks, screen printing, etc., by using LS, which is a maskless process, when compounding the entire panel, it is possible to The proportion could be set to 10% or less, generally 5 to 7% of the total.

Therefore, it also has another feature of being able to achieve high efficiency at the panel level.

Conventionally, a photoelectric conversion device has a translucent conductive film (2) formed on a translucent substrate (for example, glass (1)) with a thickness of about 0.0 mm, as shown in the vertical cross-sectional view of FIG. ITO, 5nOL, etc. are formed to a thickness of about Layer them together. Next, the back electrode was made of aluminum metal by vacuum evaporation.
It was formed to a thickness of 3 to 37A. Furthermore, epoxy resin (5
) was prepared by coating.

Sunlight or the like is used as the irradiation light (10). However, such a conventional structure is not sufficient in terms of reliability. A detailed investigation of the cause revealed that the metal constituting the back electrode (4) did not form an alloy with the semiconductor (3), and that foreign substances were diffused into the semiconductor in a high temperature test of 10σC or more, typically 150'(150'). 0.5 in about 12 to 50 hours
It was found that the particles were mixed in at a depth of 7x, degrading characteristics such as conversion efficiency from 6% to less than 1%, and causing a substantial short circuit between the two electrodes.

For this reason, in non-single-crystal semiconductors that use amorphous or semi-amorphous silicon as the main component, it is most important that the material in close contact with the semiconductor is not a metal but a conductor of a compound such as a metal oxide or metal nitride. It turns out that there is something.

The present invention has been made based on such experimental facts, and when the semiconductor (3) has one PIN junction, CTF whose main component is tin oxide is closely attached to the P-type semiconductor to form an electrode. The first feature is that indium oxide or ITO (indium oxide containing 10% by weight or less of tin oxide) is closely attached to the N-type semiconductor, resulting in a structure that does not use metal.

FIG. 2 shows a longitudinal cross-sectional view of the photoelectric conversion device of the present invention.

This photoelectric conversion device is constructed by building up a plurality of elements on the same light-transmitting substrate and framing them in a panel structure.

In the drawing, ITO is placed on the transparent substrate (1) at 1500 ~
Provided with a thickness of 2500A, and further coated with tin oxide of 200~
A CTFI (2>) with a thickness of 500 people is provided.

Furthermore, the non-single crystal semiconductor (3) having a PIN junction is a P-type S'zCt-y, (0<X<1 e.g. x=0
．． 8. ) (1ook) - ■ type Si (approx. 0.p) -
A structure of N-type microcrystalline Si (particle size of 10 to 200 nanometers) was fabricated by plasma vapor phase method. Furthermore, 1000 to 3000 people, for example 2000
It was established as CTI'2 (4) with a thickness of 1.5 mm.

This composite is made by forming a CTFI on the entire surface of the substrate (1), then scribing the CTFI into a width of about 2㎜ using LS and separating it into multiple regions (17), and further forming the semiconductor (1).
After forming 3) on the entire surface, semiconductor (3) and CTFI
was again subjected to minute Mlf (18) by LS. Further C
After forming TF2 (4) on the entire surface, it is separated into a plurality of regions (19) by LS. In this way, it is divided into a first element (20), a second element (21), a third element 2 (22), etc. For example, the connection part is connected to the first external connection electrode (15) connected to the second electrode of the first element, and the first external connection electrode (15) is connected to the second electrode of the first element. An electrode was provided in series connection in connection with the second electrode of the second element at (18). Further, the first electrode of the third element (22) is connected to another external extraction electrode bath I- (15), and the external connection electrode (16'
)It has become.

(Therefore, a plurality of elements are composited on the same substrate (1). Furthermore, this element is made of PVB (also known as Seaflex), which has a transparent heat-melted filling effect (7). (0.2-1 mm, generally 0.5 mm thick).

Furthermore, on this upper surface, a second transparent substrate of glass (
8) It has a laminated glass structure.

In the drawing, the panel has an aluminum sash frame (13
), (13'), and this and the substrate (1
) (8) and butyl rubber (14) (14'
) is indicated by a broken line to mean that a solar water heater (30) having a water cooling pipe (31) can be installed.

This water heater is located on the roof side and heats the inside of the water cooling pipe by supplying long wavelength light (1o) of sunlight, and can raise the temperature of water to 60-80'C. Solar heat can be used.

Such a structure does not occupy a large area of the roof, which is advantageous in that it can increase utilization efficiency.

FIG. 3 shows the steps involved in manufacturing the photoelectric conversion device of the present invention.

That is, FIG. 3(A) shows a CTFI (2) on a glass substrate (1).
) was formed to a thickness of 0.15 to 0.257 mm by electron beam evaporation, spraying, or CVD. This CT
F is ITO (0.15~0.25.y) +S
nO, (200 to 500 A). Alternatively, it may be 5 nOz added with a halogen element.

Furthermore, a non-single crystal semiconductor having at least one PIN or PN junction is deposited on top of this by PCVD (plasma vapor deposition method).
Laminate by layering. In general, a P-type semiconductor is formed by a reaction between silane and methane, 5iXCt<(0< x < I
- 〇, 8) is formed to a thickness of about 100λ. As the I-type semiconductor, silicon doped with hydrogen or fluorine was formed to a thickness of approximately zero by PCVD using silane or SiF. At this time, the oxygen in this silicon was set to be 5A'lO'cm' or less, preferably 5xlO%m' or less. Furthermore, silane diluted 10 to 20 times with hydrogen is added to the N-type semiconductor by PC.
It was produced by mixing phosphin from □ in the VD method. As a result, it becomes microcrystalline, which not only reduces the light absorption property but also increases the electrical conductivity >10'<n cm
) can be obtained. This N-type silicon has a thickness of 100 to 200 mm and is very important to be polycrystalline so that no light is absorbed in this region.

Next, ITO is removed by electron beam evaporation or CVD.
．． 1~0. Generally, the thickness is 0.5 mm. In order to increase the open circuit voltage, in the present invention, the P-type semiconductor is brought into close contact with tin oxide, and the N-type semiconductor is brought into close contact with tin oxide.
or ITO.

I couldn't get it.

Thus, Figure 3(A) was obtained.

Next, the procedure was as shown in Figure 53 (B). In the drawing, a heat-meltable translucent filler was placed on the element (6). PVB (polyvinyl butyral) was used as this filler. In other words, this PVB has powdered baking soda sprinkled on its surface at room temperature, so it must first be washed with water and then this baking soda (
Sodium bicarbonate) was removed and the mixture was thoroughly dried. This was done at 20-25'C. Next this PVB
The foil was arranged in the form of elements (6). Further, a light-transmitting insulating substrate was placed on the upper surface of the crepe, and then these were placed in an autoclave, and the inside of the crepe oven was evacuated.

Then, the air between this element and the PVB and between the PVB and the second glass substrate was removed, that is, deaerated.

Thereafter, it is heated in the crepe oven to 100 to 170''C, generally 120 to 15 cfc, and further heated to 7 to 13 atm/h.
This was accomplished by applying a pressure of, for example, 10 atm/cm and filling the crepe oven with the heated air.

In this way, the PVB is melted and the whole is integrated as shown in Figure 3 (C
) was obtained.

As is clear from the drawings, the element (6) has a transparent substrate made of glass (inorganic material) on the irradiation light side, and has a so-called laminated glass structure, with the back surface covered with glass (inorganic material). There is an element inside one of the substrates p.
They are placed in close contact with each other and are integrated in a complex manner.

By adopting such a structure, it was possible to have an ideal structure in which moisture and the like do not enter into the interior, and furthermore, there is no reaction between the semiconductor (3) and the metal.

Examples of the present invention are added below to further supplement the content.

Example 1 FIG. 2 is a longitudinal sectional view of an embodiment of the invention.

In the drawing, the glass substrate has dimensions of 20 cm x 60 cm. One element has a diameter of 15 mm and a diameter of 20 cm, and has a 40-stage series connection structure.

The comparison of conversion efficiency is as follows.

Conventional example Present invention 1 Present invention 2 Present invention 3 Open circuit voltage (V)
0.82 0.91 32 32 Short circuit current (to m/cm) 13.1 15.2 336
340 Fill factor (%) 58 65 54
54 Efficiency (%) 6.3 9.0 4.
84 4.9011Ts (hours) 3
>1000 >1000 >11000HII
(hours) 〜200〜200〜200＞
1000 In the above table, the conventional example has the structure shown in Figure 1,
In addition, when the area is 3 mm x 3 cm (Icm'), the structure is 3mm x 3cm (Icm'). The first embodiment of the present invention has the structure shown in FIG. 3(A), and the back electrode is made of CrF2 and made of ITO. Yes, the area is 3 mm 23 cm (1 cm'
). The present invention 2 has the structure shown in FIG. 2, and has characteristics when 40 stages are connected in series on a 20 cm x 60 cm substrate, and the filler (7) and back surface protector (8) are not provided. Furthermore, efficiency is AMI
(100 mW/cm). Also II
Ts is 150' (: high temperature storage test in the atmosphere), and does not indicate the time until the efficiency changes by 10% or more from the initial value. Also, for HUM, the humidity test in an atmosphere of 65° CRI + 90%. The effect of a change of 10% or more in
Indicates the time it takes to show the rate.

As is clear from the above results, by using CrF2 on the back surface, the efficiency could be improved from 6.3% in the conventional example to 9%. By the way, this CrF2 is 105O
When the thickness was set to A and aluminum was further formed as an electrode on top of that, the efficiency was further improved by 1%.

As described above, the first and second electrodes of the present invention are formed using CTF.
By doing so, in addition to being able to improve efficiency, it was also possible to have stable characteristics for more than 1000 hours at IITS, whereas the conventional example had characteristics for only 3 hours.

Further, when the present invention is integrated into a composite structure as shown in FIG. 2, an effective conversion efficiency of 4.84% and a voltage of 32V can be obtained. At IITS, 10
00 hours or more, but HUM is still about 200
It turned out that time and still not enough.

For this reason, if the element is made into a sandwich structure with PVB and a glass substrate on the back side, and (7') and (8) in FIG.
The optical reliability was 90%, which is approximately the same as that of Invention 2, or the optical reliability for 1000 hours or more in HllM.

Since it is a laminated glass structure, the structure shown in FIG. 2 of the present invention had the highest reliability in wind pressure tests and rain pressure tests.

In addition, in the embodiment of the present invention, the conventional example has a conversion efficiency of 6.3.
%, but this is different from other methods such as glass-CT
If the improvement can be improved to 8 to 10% by making the F interface Tescutia to reduce the reflection of light on the incident light side, the present invention L2, 3. in Example 1 can be similarly improved. It goes without saying that the characteristics can also be improved.

Further, in the present invention, the case where one PIN junction is mainly shown is shown. But this is PINPIN...P
It is only necessary to make a jN junction and at least one PN or PIN junction, and from this point of view, it has been found that the present invention has an extremely important feature that will further promote commercialization as a photoelectric conversion device panel.

In addition, for example, 4 NEDO standard panels of 40cm x 120cm, 4 pieces of 20cm x 60cm, and 4 20cm x 4
6 pieces of 0cm, 12 pieces of 20cm x 20cm, 40c
It is possible to combine three sheets of m x 40 cm to form a frame for aluminum slats, etc.

[Brief explanation of the drawing]

FIG. 1 shows a longitudinal cross-sectional view of a conventional photoelectric conversion device. FIG. 2 shows a longitudinal cross-sectional view of the composite integrated photoelectric conversion device of the present invention. FIG. 3 shows the manufacturing process of the present invention. Patent applicant 0 jAH':;'+? / 30 1O is also 2 marks

Claims (1)

[Scope of Claims] (2) A first translucent insulating substrate, a first electrode having a translucent conductive film on the substrate, and at least one that generates a photovoltaic force by light irradiation on the electrode A non-single crystal semiconductor having one PN or PIN junction, a second electrode made of a transparent conductive film on the semiconductor, and a second transparent insulating substrate provided apart from the electrode. . A photoelectric conversion device comprising a transparent insulator filled between the substrate and the second electrode. 2. In claim 1, a first electrode mainly composed of tin oxide and a non-single crystal semiconductor mainly composed of a P-type semiconductor are provided in close contact with each other to form a first interface. In addition, a photoelectric conversion device/