JP2002094089A - Method for manufacturing compound thin film solar cell - Google Patents

Abstract

(57) [Summary] [Object] To easily manufacture a compound thin film solar cell in which a short circuit does not occur between an interface of a heterojunction between a light absorbing layer and a buffer layer and an upper transparent electrode layer by a simple process. . When manufacturing a compound thin film solar cell by scribing, particularly when forming a groove for contact between the upper and lower electrodes, a step of forming a wide groove extending to the lower electrode surface by mechanical scribing;
An insulating film is formed from above the groove so that the insulating material is buried inside the wide groove, and a narrow groove reaching the lower electrode surface by mechanical scribing at the center position of the wide groove. And the step of forming

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a compound thin film solar cell by scribe processing.

[0002]

2. Description of the Related Art Conventionally, when a compound thin film solar cell is manufactured by scribing, a lower electrode layer 2 made of a Mo thin film is formed on a glass substrate 1 as shown in FIG.
A first step (FIG. 7A) of forming a groove L for separating a lower electrode by laser scribe processing, and a light absorbing layer 3 made of a compound semiconductor (CIGS) thin film from above the lower electrode layer 2 for a hetero junction. A buffer layer 4 made of a CdS thin film and an insulating layer 5 made of a ZnO thin film
A second step of forming a groove M1 'for contact between lower electrodes by mechanical scribing at a position laterally separated from the groove L for lower electrode separation by several hundred μm to the lower electrode surface (FIG. 7). b) and ZnOAl from above the insulating layer 5
The third step of forming the upper transparent electrode layer 6 made of a thin film, reaching the lower electrode surface by mechanical scribing, and forming the lower electrode separating groove M2 '(FIG. 7)
c).

[0003]

The problem to be solved is that when the compound thin film solar cell is manufactured by the scribe processing step shown in FIG. 7, the side face of the groove M1 'for contact between the upper and lower electrodes is formed. Since the insulating layer is not insulated, the interface between the heterojunction between the light absorbing layer 3 and the buffer layer 4 and the upper transparent electrode layer 6 are short-circuited.

[0004]

According to the present invention, when a compound thin film solar cell is manufactured by scribe processing, a short circuit occurs between the interface of the heterojunction between the light absorbing layer and the buffer layer and the upper transparent electrode layer. In particular, to avoid
When forming a groove for contact between the upper and lower electrodes,
A step of forming a wide groove extending to the lower electrode surface by mechanical scribe processing, and forming an insulating film from above the groove so that an insulating material is buried inside the wide groove, and then forming a wide groove. Forming a narrow groove extending to the lower electrode surface by mechanical scribing at the center position of the groove, thereby forming insulating material walls on the side surfaces of the upper and lower electrode contact grooves. Like that.

[0005]

FIG. 1 shows a method of manufacturing a compound thin film solar cell according to the present invention, which comprises four steps by scribe processing.

First, as a first step shown in FIG. 1A, a lower electrode layer 2 made of a Mo thin film is formed on a glass substrate 1, and a groove L for separating the lower electrode is formed by laser scribing. I do. Next, as a second step shown in FIG.
GS) A light absorbing layer 3 made of a thin film and a buffer layer 4 made of a CdS thin film for heterojunction are sequentially laminated (at this time, the inside of the groove L is filled with the compound semiconductor), and a groove L for separating a lower electrode is formed. A wide groove M1 reaching the lower electrode surface is formed by mechanical scribing at a position laterally separated from the substrate by several hundred μm. Next, FIG.
As a third step shown in FIG.
An insulating layer 5 made of a thin film is formed (at this time, the inside of the groove M1 is filled with the insulating material), and the wide groove M is formed.
A groove M2 for contact between lower electrodes is formed in the center position of 1 by mechanical scribing on a narrow side reaching the lower electrode surface. Finally, as a fourth step shown in FIG. 5D, an upper transparent electrode layer 6 made of a ZnOAl thin film is formed from above the insulating layer 5 (at this time, the inside of the groove M2 is filled with the electrode material. ), A groove M3 for lower electrode separation is formed by mechanical scribing to reach the lower electrode surface.

FIG. 2 shows another method for manufacturing a compound thin film solar cell according to the present invention.

In this case, in particular, the second step (FIG. 2)
In b), the light absorbing layer 3, the buffer layer 4, and the insulating layer 5 are sequentially stacked from above the lower electrode layer 2, and a wide groove M1 is formed by mechanical scribe processing.
In the third step (FIG. 2C), the insulating layer 5 is formed again thereon, and the narrow groove M2 is formed by mechanical scribing. In this case, the first step (FIG. 2A) and the fourth step (FIG. 2D) are the same as in the manufacturing method shown in FIG.

According to the method of manufacturing the compound thin film solar cell shown in FIGS. 1 and 2, a wide groove M1 is formed by mechanical scribing prior to forming the groove M2 for contact between the upper and lower electrodes. By performing the second step, the insulating material wall 7 is formed on the side surface of the upper and lower electrode contact groove M2, and the interface between the light absorbing layer 3 and the buffer layer 4 at the heterojunction interface is formed. A short circuit with the upper transparent electrode layer 6 does not occur.

FIG. 5 shows a mechanical scribing blade for forming a wide groove M1. Here, the diameter D =
The diameter φ1 of the tip of a blade having a size of 3 mm and a length L = 4 cm is about 440 to 900 μm.

FIG. 6 shows a normal mechanical scribe blade for forming a narrow groove M2. That is, the diameter φ2 of the tip of the blade having a diameter D = 3 mm and a length L = 4 cm is 100 μm.

FIG. 3 shows still another method of manufacturing the compound thin film solar cell according to the present invention.

In this case, there are five steps by scribe processing.

First, as a first step shown in FIG. 1A, a lower electrode layer 2 is formed on a glass substrate 1 and a groove L for lower electrode separation is formed by laser scribing. Next, as a second step shown in FIG. 2B, a light absorbing layer 3, a buffer layer 4, and an insulating layer 5 are sequentially stacked from above the lower electrode layer 2 (in this case, the inside of the groove L is formed of a compound semiconductor). A wide groove M1 reaching the lower electrode surface is formed by mechanical scribing at a position laterally separated from the lower electrode separating groove L by several hundred μm by mechanical scribing.
Next, as a third step shown in FIG.
To form an insulating film 9 of MgO, SiN: H or the like in the wide groove M1. Next, as a fourth step shown in FIG. 4D, the mask 8 is removed, and mechanical scribe processing is performed at the center position of the wide groove M1 to reach the lower electrode surface, and the narrow upper and lower inter-electrode contacts are formed. Groove M2 is formed. Finally, as a fifth step shown in FIG.
An upper transparent electrode layer 6 is formed from above the insulating layer 5 (at this time, the inside of the groove M2 is filled with the electrode material), and reaches the lower electrode surface by mechanical scribing.
A groove M3 for lower electrode separation is formed.

FIG. 4 shows still another method of manufacturing the compound thin film solar cell according to the present invention.

In this case, in particular, the second step (FIG. 4)
In b), the light absorbing layer 3 and the buffer layer 4 are sequentially stacked from above the lower electrode layer 2, and a wide groove M1 reaching the lower electrode surface is formed by mechanical scribing. Then, in a fourth step (FIG. 4D), after removing the mask 8, the insulating layer 5 is formed, and a mechanical scribe process is performed at the center position of the wide groove M1 to reach the lower electrode surface. A groove M2 for contact between the lower electrodes is formed above the narrow part. In this case, the first step (FIG. 4A) and the third step (FIG. 4C)
The fifth step (FIG. 4E) is the same as the manufacturing method shown in FIG.

According to the method of manufacturing the compound thin film solar cell shown in FIGS. 3 and 4, the wide groove M1 is formed by mechanical scribing prior to forming the groove M2 for contact between the upper and lower electrodes. And a third step of forming the insulating film 8 in the wide groove M1 portion, thereby forming the insulating material walls 7 on the side surfaces of the upper and lower inter-electrode contact grooves M2. The light absorbing layer 3
The short circuit does not occur between the interface of the hetero junction between the semiconductor device and the buffer layer 4 and the upper transparent electrode layer 6.

[0018]

As described above, according to the present invention, when manufacturing a compound thin film solar cell by scribing, particularly when forming a groove for contact between the upper and lower electrodes,
A step of forming a wide groove extending to the lower electrode surface by mechanical scribe processing, and forming an insulating film from above the groove so that an insulating material is buried inside the wide groove, and then forming a wide groove. Forming a narrow groove extending to the lower electrode surface by mechanical scribing at the center position of the groove, thereby forming insulating material walls on the side surfaces of the upper and lower electrode contact grooves. With such a configuration, it is possible to easily manufacture a compound thin film solar cell in which the interface of the heterojunction between the light absorbing layer and the buffer layer and the upper transparent electrode layer are not short-circuited by a simple process. Has advantages.

[Brief description of the drawings]

FIG. 1 is a process chart showing a method for manufacturing a compound thin film solar cell according to the present invention.

FIG. 2 is a process chart showing another method for manufacturing a compound thin film solar cell according to the present invention.

FIG. 3 is a process chart showing still another method for manufacturing a compound thin film solar cell according to the present invention.

FIG. 4 is a process chart showing still another method for manufacturing a compound thin film solar cell according to the present invention.

FIG. 5 is a front view showing a mechanical scribe blade for forming a wide groove.

FIG. 6 is a front view showing a blade for mechanical scribe forming a narrow groove.

FIG. 7 is a process chart showing a conventional method for manufacturing a compound thin film solar cell.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Glass substrate 2 Lower electrode layer 3 Light absorption layer 4 Buffer layer 5 Insulating layer 6 Upper transparent electrode layer 7 Insulating material wall 8 + Electrode part L Lower electrode separation groove M1 Wide groove M2 Upper and lower electrode contact Groove M3 Groove for separating upper and lower electrodes

Claims (4)

[Claims] A first step of forming a lower electrode layer on a substrate and forming a groove for separating the lower electrode by laser scribing; and forming a compound semiconductor layer and a heterojunction on the lower electrode layer from above the lower electrode layer. A second step of sequentially laminating a buffer layer and forming a wide groove extending to the lower electrode surface by mechanical scribing at a position laterally separated from the lower electrode separating groove by a predetermined amount; A third step of forming an insulating layer from above and forming a narrow upper and lower inter-electrode contact groove by mechanical scribing at the center of the wide groove by mechanical scribing; A fourth step of forming an upper electrode layer from above and forming a groove for separating the lower electrode from the lower electrode surface by mechanical scribing to a lower electrode surface. 2. A first step of forming a lower electrode layer on a substrate and forming a groove for separating the lower electrode by laser scribing, and a step of forming a compound semiconductor layer and a heterojunction from above the lower electrode layer. A second step of sequentially laminating a buffer layer and an insulating layer to form a wide groove reaching the lower electrode surface by mechanical scribing at a position laterally separated from the lower electrode separation groove by a predetermined amount; Third step of further forming the same insulating layer from above the insulating layer, and forming a narrow upper and lower inter-electrode contact groove by mechanical scribing at the center position of the wide groove. And a fourth step of forming an upper electrode layer from above the insulating layer, reaching the lower electrode surface by mechanical scribing, and forming a groove for separating the lower electrode. Pond manufacturing method. 3. A first step of forming a lower electrode layer on a substrate and forming a groove for separating the lower electrode by laser scribing, and forming a compound semiconductor layer and a heterojunction on the lower electrode layer from above the lower electrode layer. A second step of sequentially laminating a buffer layer and an insulating layer to form a wide groove reaching the lower electrode surface by mechanical scribing at a position laterally separated from the lower electrode separation groove by a predetermined amount; A third step of forming an insulating film in the wide groove portion, and mechanical scribe processing at the center position of the wide groove to the lower electrode surface to form a narrow upper and lower electrode contact groove. A compound thin film comprising: a fourth step of forming; and a fifth step of forming an upper electrode layer from above the insulating layer, reaching the lower electrode surface by mechanical scribing, and forming a groove for separating the lower electrode. Solar power Pond manufacturing method. 4. A first step of forming a lower electrode layer on a substrate and forming a groove for separating a lower electrode by laser scribing, and forming a compound semiconductor layer and a heterojunction on the lower electrode layer from above the lower electrode layer. A second step of sequentially laminating a buffer layer and forming a wide groove extending to the lower electrode surface by mechanical scribing at a position laterally separated from the lower electrode separation groove by a predetermined amount; A third step of forming an insulating film on the groove, forming an insulating layer on the insulating film and the buffer layer, and forming a central groove of the wide groove to reach the lower electrode surface by mechanical scribing. A fourth step of forming a groove for a lower inter-electrode contact on the narrow top, and forming an upper electrode layer on the insulating layer;
A fifth step of forming a groove for lower electrode separation on the lower electrode surface by mechanical scribe processing, and a fifth step of manufacturing the compound thin film solar cell.