JPS61163671A - Thin-film solar cell - Google Patents

Abstract

PURPOSE:To increase the area of an output terminal, to connect a lead wire and an element easily and to improve reliability by extending a first electrode and a second electrode holding amorphous Si up to the back through the side surface of an insulating substrate. CONSTITUTION:First electrodes 2, an a-Si layer 3, a second electrode 4 con sisting of ITO, etc. and a protective film 5 are formed onto an insulating sub strate 1 in succession. The first electrodes 2 and the second electrode 4 are shaped through an electron beam evaporation method, etc. by using a mask, and these electrodes 2, 4 are extended up to the back through a side surface and output terminal sections 6 are formed on the back side. Accordingly, lead wires and an element are connected easily, thus improving reliability.

Description

[Detailed description of the invention] Industrial applications The present invention relates to thin film solar cells.

2. Description of the Related Art Conventionally, a thin-film solar cell of the Renotane type has a structure as shown in FIG. In Figure 4, 1 indicates glass, ceramic,
This is an insulating substrate such as polyimide film. 3 is an amorphous silicon layer that generates electrons and holes that contribute to photovoltaic power generation, and is generally a p-type amorphous silicon layer doped with boron, or an undoped film! Type amorphous silicon layer, phosphorus doped +1? F -JFIζYom1, 'tu
2.4 is a first electrode and a second electrode facing each other with an amorphous silicon layer in between, and the insulating substrate 1 has excellent translucency. In the case of a substrate such as a glass substrate, the first electrode is ITO,5
It is a transparent conductive film such as n02, and metal such as aluminum, silver, chromium, etc. is used for the bamboo 2 electrode. Further, when the insulating substrate 1 is made of a ceramic, polyimide film substrate, etc. that does not have translucency, the first electrode is made of a metal such as aluminum, silver, or chromium, and the second electrode is made of a metal such as aluminum, silver, or chromium. Generally, a transparent conductive film such as ITO, 5n02, etc. is used. A protective film 6 is coated with epoxy resin or the like by screen printing, but if the insulating substrate 1 is a non-transparent substrate, the protective film 6 is on the light incident side, so it is coated with a transparent resin or the like. A transparent protective film must be formed. 6 is an output terminal section.

Problems to be Solved by the Invention In such a conventional configuration, since the output terminal portions 6 for extracting electromotive force are located at both ends of the thin film solar cell, the leads m ft
At 5jlJ a, there were 8 kerege outside cloth ivy in 2 places. Furthermore, there is a demand for increasing the power generation area configured on the board, and the only way to achieve this is to reduce the area of the output terminal section 6.

The smaller the area of the terminal portion, the greater the possibility that problems such as poor contact will occur in terms of reliability. This is especially true for small devices such as solar cells for wristwatches. Furthermore, if a translucent substrate is not used, the output terminal portion will be provided on the same surface as the light-receiving surface of the substrate, making it difficult to take lead wires when incorporating it into electronic equipment.

An object of the present invention is to provide a thin film solar cell that solves the above-mentioned drawbacks.

Means for Solving the Problem In order to solve this problem, the present invention extends the first electrode and the second electrode through the side surface of the substrate to the back side, and outputs from a part of the electrode. It's something I'm trying to release.

Function: With this configuration, the output terminal portion can be provided at any position on the surface of the substrate opposite to the side on which the solar cells are formed.
Moreover, the size of the electrode as a terminal can be increased.

Embodiment 1 A first embodiment of the present invention will be described below with reference to the drawings. FIGS. 1A, 1B, and 1C are a top view, a bottom view, and a sectional view of a thin film solar cell according to an embodiment of the present invention. In the figure, 1 is an insulating substrate such as ceramic or polyimide resin film, and 2 is aluminum.

A first electrode made of silver, chromium, or the like is formed by appropriately masking both sides of the insulating substrate 1 using an electron beam evaporation method or the like so as to extend through the side surface of the substrate to the back surface side. 3 is an amorphous silicon layer, 4 is a second electrode, I T O, 5
A transparent conductive film such as N02 is used, and by applying an appropriate mask using electron beam evaporation, etc., as with the first electrode, it is possible to coat the film from the top surface of the amorphous silicon layer, through the side surface of the substrate, and to the back surface side. It is formed by vapor deposition extending up to the point. 5 is a protective film.

A transparent resin is applied to the entire surface of the element by screen printing. According to the above method, the output terminal section 6 can be provided on the back side of the board, and as shown in FIG.
It becomes possible to form any pattern and size as shown in (b). In addition, there is also the advantage that buttering of the transparent resin is not required. Also, instead of depositing on both sides of the substrate at once,
The output terminal part with the pattern shown in (b) is formed by vapor deposition on the back surface of the substrate, and when forming the first and second electrodes on the element surface, connections are made by utilizing the wraparound of the vapor deposited atoms to the back surface of the substrate. The same effect can be obtained.

Figure 3(i) and (b) show a top view and a cross-sectional view when the present invention is applied to a thin film solar cell having a general series connection structure between cells, which is different from that shown in Figure 1. In Fig. 3(a), 1 to e are the first
It performs the same function as the one shown in the figure. With the configuration shown in the figure, by providing the output terminal section on the back surface, it is possible to increase the light receiving area of the photovoltaic section of the solar cell to about L over the entire substrate.

Effects of the Invention By forming the first electrode and the second electrode to extend to the back side of the insulating substrate and using a part as the output extraction electrode, the output terminal portion can be provided at any position on the back side, Moreover, since the area can be increased, the connection between the lead wire and the element becomes easier, and reliability is improved.

[Brief explanation of drawings]

FIGS. 1(a), (b), and (t-) are a top view, a bottom view, and a cross-sectional view of a thin film solar cell according to an embodiment of the present invention, and FIGS. 2(a) and (b) are views of a substrate. A top view showing the output terminal part of an arbitrary pattern formed on the back surface, FIG.
), [Yes]) are a top view and a sectional view of a thin film solar cell showing another embodiment of the present invention, and FIG. 4 is a top view showing a conventional thin film solar cell. 1... Insulating substrate, 2... First electrode, 3
. . . Amorphous silicon layer, 4 . . . Second electrode, 6 . . . Protective film. 6... Output terminal section. Name of agent: Patent attorney Toshio Nakao and 1 other person
2rXI 6i=-earthxljh硅p (CL) Fig. 3 (br 4 6

Claims (1)

[Claims] A thin film solar cell in which a first electrode and a second electrode sandwiching an amorphous silicon layer are formed on an insulating substrate, the first and second electrodes extending through the side surface of the insulating substrate to the back surface. Thin film solar cells.