JP2002076380A - Method for manufacturing thin-film solar cell module - Google Patents

Abstract

(57) [Problem] To provide a method capable of improving the yield when manufacturing a small-sized solar cell module by cutting a large-sized glass substrate. SOLUTION: A plurality of solar cells (2) connected in series by sequentially forming a string-shaped scribed transparent electrode layer, a photoelectric conversion semiconductor layer and a back electrode layer on a large area glass substrate (1). ) Is formed, and the glass substrate is cut to obtain a thin-film solar cell module (1) having a predetermined size.
In manufacturing 0), a process for mechanically damaging the film surface of the solar cell (2), for example, an edge polishing process for polishing a film formed on the peripheral portion (1a) of the glass substrate (1); After cutting the glass substrate (1), reverse bias processing is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a thin-film solar cell module.

[0002]

2. Description of the Related Art In recent years, the use of solar cells has become widespread, and accordingly, solar cell modules of various dimensions have been required. In response to such demands, a method of manufacturing a small-sized solar cell module by cutting a large-sized glass substrate has been adopted.

According to this method, a transparent electrode layer, a photoelectric conversion semiconductor layer, and a back electrode layer scribed in a string are sequentially formed on a large-area glass substrate to form a plurality of solar cells connected in series. After that, the glass substrate is cut to manufacture a thin film solar cell module having a predetermined small size.

In a method in which a plurality of solar cells are formed on a large-area glass substrate and used as it is as a thin-film solar cell module, a short-circuit portion is removed by reverse bias treatment after forming the solar cells. The thin film on the periphery of the substrate is removed (edge polishing) by blasting. After that, formation of busbar electrode, lead attachment, sealing,
Installation of a terminal box is performed.

However, these steps are directly applied to a method of manufacturing a small-sized solar cell module by cutting a large-sized glass substrate, and after reverse biasing, edge polishing by blasting or cutting of the glass substrate is performed. It has been found that the failure rate of the solar cell module increases, such as a decrease in the maximum output, and the yield decreases.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method capable of improving the yield when a large-sized glass substrate is cut to produce a small solar cell module.

[0007]

According to a method of manufacturing a thin film solar cell module of the present invention, a transparent electrode layer, a photoelectric conversion semiconductor layer, and a back electrode layer scribed in a string are sequentially formed on a large-area glass substrate. After forming a plurality of solar cells connected in series with each other by cutting, the glass substrate is cut to produce a thin film solar cell module of a predetermined size, and mechanical damage is applied to the film surface of the solar cell. A reverse bias process is performed after the process.

In the present invention, as a treatment for mechanically damaging the film surface of the solar cell, cutting (cutting and cutting) or subsequent chamfering in water (including a draining step) of the glass substrate, Alternatively, edge polishing treatment (including a polishing agent removing step) for polishing a film formed on a peripheral portion of a glass substrate can be given.

In the method of manufacturing a thin-film solar cell module according to the present invention, an edge polishing process (including a step of removing an abrasive) for polishing a film formed on a peripheral portion of a glass substrate, and a cutting (cutting line) of the glass substrate are performed. It is preferable to perform reverse bias treatment after performing undercutting and folding) and chamfering in water (including a draining step).

In the present invention, the edge polishing process is performed by rotating a diamond blade or the like for grinding or by blasting.

In the present invention, in the reverse bias treatment, it is preferable to perform a plurality of operations of applying a reverse voltage of 0.2 to 20 V per string for a period of 10 seconds or less. In this case, the reverse voltage may be an AC voltage or a DC voltage.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The present inventors, when manufacturing a small solar cell module by cutting a glass substrate having a large area, after applying a reverse bias treatment to the formed solar cell, As a result of examining the cause of an increase in the failure rate of the solar cell module when the edge is polished by blasting or the glass substrate is cut, the following conclusions have been reached.

The reverse bias process is a process in which a large current is applied to a short-circuit portion generated in a solar battery cell to scatter or alter the short-circuit portion to restore electrical characteristics. It is considered that the altered substance in the short-circuited portion generated by this treatment remains in a state of being raised on the surface of the solar cell. In this state, if a process of mechanically damaging the film surface of the solar battery cell is performed, it is estimated that the altered substance is pushed into the leak location again, and the restored electrical characteristics deteriorate again.

[0014] For example, when a small solar cell module is cut out by cutting (cutting and breaking) a glass substrate, the four sides of the module are ground in water and chamfered. In this step, the module is fixed. To do this, a rubber belt is pressed against the cell surface. In addition, the nip roll comes into contact with the cell surface of the module when draining is performed thereafter. If the step of applying pressure to the cell surface is performed after the reverse bias treatment, the altered substance generated by the reverse bias treatment is pushed again into the leak location as described above, and the restored electrical characteristics deteriorate again. In addition, when the edge is polished by blasting after the reverse bias treatment and the polishing step is performed, the cell surface of the module is damaged by the abrasive, and the deteriorated substance is pushed in again, and the restored electrical characteristics deteriorate again. I do. Moreover, it is estimated that the influence of the intrusion of the altered substance on the deterioration of the electric characteristics is more remarkable in a small solar cell module than in a large solar cell module.

On the other hand, in the method of the present invention, reverse bias treatment is performed after the step of mechanically damaging the film surface of the solar cell on which the transparent electrode layer, the photoelectric conversion semiconductor layer, and the back electrode layer are laminated. Therefore, it is possible to prevent the deterioration of the electric characteristics due to the intrusion of the altered substance caused by the reverse bias treatment.

In the present invention, formation of a solar cell by film formation and scribing, edge polishing, cutting of a glass substrate, reverse bias treatment, formation of a bus bar electrode, lead attachment, sealing,
It is preferable to manufacture the thin-film solar cell module in the order of mounting the terminal box. After the reverse bias treatment, in order to avoid the deterioration of the electric characteristics caused by the above-mentioned deteriorated material, washing is performed after the reverse bias treatment to remove the deteriorated material, and the cell surface of the solar cell is minimized in the subsequent process. Preferably, no pressure is applied.

[0017]

An embodiment of the present invention will be described below with reference to FIG. In this embodiment, a large-sized glass substrate is cut to produce four small-sized thin-film solar cell modules.

As shown in FIG. 1A, 910 mm × 4
A glass substrate 1 having a size of 55 mm and having a transparent electrode layer made of SnO ₂ was prepared. After scribing the transparent electrode layer by laser processing, it was washed. An amorphous silicon-based photoelectric conversion layer was formed on the transparent electrode layer by plasma CVD. After scribing the photoelectric conversion layer by laser processing, it was washed. A back electrode layer was formed on the photoelectric conversion layer by sputtering. After scribing the photoelectric conversion layer and the back electrode layer by laser processing,
Washed. In this way, a structure in which the 50-stage string-shaped solar cells 2 were connected in series was formed (for convenience,
In the figure, the number of strings is smaller than the actual number).

Next, as shown in FIG. 1B, a scribe line 3 having a width of 10 mm was provided in the cut portion so as to be divided into four in the longitudinal direction of the glass substrate 1 by laser processing.

Next, as shown in FIG. 1 (C), an edge polishing process is performed using sand blast to polish the film formed on the peripheral portion 1a of the glass substrate with a width of 5 mm, and then remove the abrasive. did.

At this time, a reverse bias treatment was performed to remove a short-circuit portion of the solar cell. In this reverse bias processing, 2V, 4V, 8V,
The operation of applying a reverse bias voltage of 2 V was performed sequentially over all strings.

Further, as shown in FIG. 1 (D), the glass substrate 1 was cut at the center of the scribe line 3 at the cut portion using a diamond cutter, and four small solar cell modules 10 were manufactured. Next, each of the small solar cell modules 10 was put on a grinder in water with a rubber belt pressed against the cell surface, and the four sides of the module were ground and chamfered. Thereafter, draining was performed with the nip roll in contact with the cell surface of the module.

At this point, reverse bias processing is performed again.
The short-circuit part of the solar cell was removed. Also in this reverse bias processing, as described above, two strings are placed between two adjacent strings.
The operation of applying reverse bias voltages of V, 4 V, 8 V, and 2 V was sequentially performed on all strings.

The above steps were performed on five glass substrates, and a total of 20 small solar cell modules were manufactured.

In the above method, blast processing is performed.
Before (before blast), after blasting (blast
After), after performing the first reverse bias processing (first bias)
After processing), after cutting the glass substrate (after cutting),
And after performing the second reverse bias processing (second bias processing).
After that, the electrical characteristics of the solar cell module were evaluated.
Specifically, AM1.5 of the solar cell module
Light 100mW / cm ^TwoAnd the maximum output P
_max, Open-circuit voltage V_OC, Short-circuit current I_SC, Fill factor (F
F) and measure the average value of the 20 solar cell modules.
I asked. Table 1 shows the results.

As is clear from Table 1, the electrical characteristics of the solar cell module are recovered by performing the biasing process after the blasting process and after the cutting of the glass substrate.
As described above, when a large-sized glass substrate is cut to manufacture a small-sized solar cell module, it is better to perform a reverse bias process after performing a process of applying pressure to the film surface of the solar cell, thereby improving the yield. It is clear that the above is effective.

[0027]

[Table 1]

[0028]

As described above in detail, according to the present invention, it is an object of the present invention to provide a method capable of improving the yield when a large-sized glass substrate is cut to produce a small-sized solar cell module.

[Brief description of the drawings]

FIG. 1 is a perspective view for explaining a method for manufacturing a thin-film solar cell module according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Glass substrate 2 ... Solar cell 3 ... Scribe line 10 ... Solar cell module

Claims (7)

[Claims] 1. After forming a string-shaped scribed transparent electrode layer, a photoelectric conversion semiconductor layer, and a backside electrode layer on a large-area glass substrate in order, to form a plurality of solar cells connected in series to each other. In manufacturing a thin-film solar cell module having a predetermined size by cutting a glass substrate, a reverse bias process is performed after performing a process of mechanically damaging a film surface of the solar cell. A method for manufacturing a solar cell module. 2. The method for manufacturing a thin-film solar cell module according to claim 1, wherein the process of mechanically damaging the film surface of the solar cell is cutting or chamfering the glass substrate. 3. A process for mechanically damaging the film surface of the solar battery cell is an edge polishing process for polishing a film formed on a peripheral portion of the glass substrate. 3. The method for manufacturing a thin-film solar cell module according to item 1. 4. After forming a string-shaped scribed transparent electrode layer, a photoelectric conversion semiconductor layer, and a backside electrode layer on a large-area glass substrate in order, to form a plurality of solar cells connected in series to each other. In manufacturing a thin-film solar cell module having a predetermined size by cutting a glass substrate, an edge polishing process of polishing a film formed on a peripheral portion of the glass substrate, and a reverse after performing the cutting of the glass substrate. A method for producing a thin-film solar cell module, comprising performing a bias treatment. 5. The method according to claim 3, wherein the edge polishing is performed by grinding or blasting. 6. The method according to claim 1, wherein the reverse bias process is a process of performing a plurality of operations of applying a reverse voltage of 0.2 to 20 V per string for a time period of 10 seconds or less. A method for manufacturing a thin-film solar cell module according to any one of the above. 7. The method according to claim 6, wherein the reverse voltage is an AC voltage.