JP2014060356A - Thin film solar cell and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thin film solar cell which can increase the output by widening the effective area of a transparent electrode layer, and can decrease the failure rate when manufacturing a thin film solar cell while ensuring insulation in a second through hole, and to provide a manufacturing method of a thin film solar cell.SOLUTION: In a thin film solar cell 1, a transparent electrode layer 5 and a second back electrode layer 6 are insulated electrically, by separating the transparent electrode layer 5 around a second through hole 8 by means of a blade body 12, by using a separating groove 11.

Description

  The present invention relates to a thin film solar cell in which a metal electrode layer, a photoelectric conversion layer, and a transparent electrode layer are laminated on a film substrate, and a method for producing the same, and in particular, molybdenum is used for at least a part of the metal electrode layer. The present invention relates to a thin film solar cell.

Some thin film solar cells use a series connection structure called SCAF (Series Connection through Structures formed on Film). In this series connection structure, a thin film solar cell divided into a plurality of regions is formed by laser patterning, and a plurality of thin film solar cells divided by a plurality of through holes penetrating the substrate are connected in series. .
FIG. 5 is a plan view of a conventional SCAF type thin film solar cell. 6 is a cross-sectional view taken along the line AA in FIG. 5, and FIG. 7 is a cross-sectional view taken along the line BB in FIG.

  As shown in FIGS. 6 and 7, the conventional SCAF type thin film solar cell 21 includes an insulating substrate 22. Metal electrode layers 23 are formed on both surfaces 22 a and 22 b of the insulating substrate 22. Here, the metal electrode layer 23 on one surface 22a of the insulating substrate 22 functions as the back electrode layer 23a, and the metal electrode layer 23 on the other surface 22b of the insulating substrate 22 is the first back electrode. It functions as the layer 23b.

  Moreover, as shown in FIG.6 and FIG.7, the photoelectric converting layer 24 and the transparent electrode layer 25 are laminated | stacked in the said order on the back surface electrode layer 23a. On the other hand, the second back electrode layer 26 is laminated on the first back electrode layer 23b.

  As shown in FIGS. 6 and 7, the insulating substrate 22 is provided with a first through hole 27 penetrating the insulating substrate 22, and the transparent electrode layer 24 and the second back electrode layer 26 are formed. The first through hole 27 is electrically connected. Further, as shown in FIG. 6, the insulating substrate 22 is provided with a second through hole 28 that penetrates the insulating substrate 22, and the back electrode layer 23 a and the first back electrode layer 23 b include the second through hole 28. Are electrically connected through the through-holes 28.

  As shown in FIG. 5, the layer stacked on one surface 22 a of the insulating substrate 22 is divided by the first patterning line 29, and the layer stacked on the other surface 22 b of the insulating substrate 22 is It is divided by two patterning lines 30. Thereby, the laminated layer on the insulating substrate 22 is divided into a plurality of unit cells.

  Here, the first patterning lines 29 and the second patterning lines 30 are alternately arranged on the insulating substrate 22. By separating the electrode layers on both surfaces 22a and 22b of the insulating substrate 22 from each other and connecting the electrode layers on both surfaces 22a and 22b of the insulating substrate 22 with the second through-holes 28, adjacent unit cells It has a structure connected in series.

  On the other hand, Patent Document 1 discloses another example of a conventional SCAF type thin film solar cell. In the thin film solar cell of Patent Document 1, a first electrode layer, a photoelectric conversion layer, and a second electrode layer are laminated on one surface of a film substrate made of an electrically insulating resin, and the opposite side of the film substrate ( On the back surface, a third electrode layer and a fourth electrode layer are laminated. A separation groove is formed around the connection hole by laser light irradiation so that the transparent electrode surrounds the connection hole.

  Patent Document 2 describes that a groove for electrode separation is processed by a blade edge in order to manufacture a thin film solar cell with a high yield.

WO2012 / 105079 A1 JP 2010-207945 A

However, in the configuration of FIG. 5 and Patent Document 1 described above, the following problems occur.
First, in the configuration of FIG. 5, when forming the transparent electrode layer 26 so that the transparent electrode layer 25 and the second back electrode layer 26 do not contact with each other in the second through hole 28, the second through hole is formed. Mask processing was performed in the vicinity of 28. Therefore, as shown in FIG. 7B, the transparent electrode layer 25 is not formed in the vicinity of the second through hole 28. Therefore, in the conventional configuration, the effective area of the transparent electrode layer 25 is limited. The second through-holes 28 are arranged at regular intervals in consideration of the electric resistance of the first and second back electrode layers 23b and 26. Therefore, regions where the transparent electrode layer 25 cannot be formed on the insulating substrate 22 are provided at regular intervals. Therefore, there is a problem that the effective area of the transparent electrode layer 25 is reduced, and the output of the thin film solar cell 21 is also reduced in proportion thereto.

  Further, since the vicinity of the second through hole 28 is masked, the transparent electrode layer 25 on the insulating substrate 22 and the transparent electrode layer 25 on the insulating substrate 22 are damaged by the contact between the transparent electrode layer 25 on the insulating substrate 22 and the mask. There was a possibility. Thus, when the layer on the insulating substrate 22 is damaged, the leakage current and the like increase, and there is a problem that the defect rate when manufacturing the thin-film solar cell 21 increases.

  In the configuration disclosed in Patent Document 1, a separation groove is formed by a laser around the connection hole. When the separation groove is formed by this laser, the processing can be performed when the transparent electrode is as thin as 100 nm or less. However, for example, a compound-type solar cell becomes thicker, and when it is 200 to 2000 nm, the necessary laser energy is increased, and the price of the processing apparatus is increased, and it is necessary to increase the accuracy of energy to be controlled. Problems arise.

On the other hand, as shown in Patent Document 2, for CIGS solar cells, the processing of the separation line has been performed by scanning the blade-shaped processing portion, but it has been used only for linear processing.
The present invention has been made in view of such circumstances, and its purpose is as means for increasing the output of a thin-film solar cell by forming a separation groove in the transparent electrode layer around the connection hole to increase the effective area. An object of the present invention is to provide a thin-film solar cell that can be simply configured and a method for manufacturing the same.

In order to solve the above problems, according to the present invention,
On one surface of the insulating substrate, a back electrode layer containing at least part of molybdenum, a photoelectric conversion layer, and a transparent electrode layer are laminated in this order, and the other surface of the insulating substrate has a first electrode A back electrode layer and a second back electrode layer are stacked in this order, and the insulating substrate is formed into a plurality of unit cells by alternately forming patterning lines on the layers stacked on both sides of the insulating substrate. The transparent electrode layer and the second back electrode layer are electrically connected via a first through hole penetrating the insulating substrate, and the back electrode layer and the first back electrode are divided. In a thin film solar cell in which layers are electrically connected via a second through hole penetrating the insulating substrate, and adjacent unit cells are connected in series,
The transparent electrode layer around the second through-hole is separated by a groove formed by scanning (rotation) of a blade, and the transparent electrode layer and the second back electrode layer are electrically insulated. Suppose that

Moreover, according to the present invention,
Forming a second through hole in the insulating substrate;
Forming a back electrode layer containing molybdenum at least in part on one surface of the insulating substrate, and forming a first back electrode layer on the other surface of the insulating substrate;
After forming the back electrode layer and the first back electrode layer, forming a first through hole in the insulating substrate;
Laminating a photoelectric conversion layer and a transparent electrode layer in this order from one surface side of the insulating substrate, and laminating a second back electrode layer from the other surface side of the insulating substrate;
Forming alternating patterning lines for layers laminated on both sides of the insulating substrate, and dividing the insulating substrate into a plurality of unit cells;
At least the transparent electrode layer is scanned (rotated) with a blade, the transparent electrode layer is divided around the second through hole, and the transparent electrode and the second back electrode are electrically insulated. Steps,
Is included.
This manufacturing method is not a method using a conventional laser, but is performed by removing a transparent electrode by scanning a blade body around a through hole. Since the blade is hard in molybdenum (molybdenum has a Vickers hardness of 1530 MPa), it can be processed by removing only a part of the transparent electrode and the power generation layer above the electrode.

According to the method for manufacturing a thin film solar cell of the present invention, the blade is rotated around the axis of the blade tool and pressed against the solar cell.
Furthermore, according to the method for manufacturing a thin film solar cell of the present invention, a plurality of the blade bodies are provided around the same axis of the blade body tool.

Moreover, according to the manufacturing method of the thin film solar cell of this invention, the processing part provided with two or more blade tools is provided, and a process is further speeded up by carrying out several processes simultaneously.
Further, the processing unit is intermittently moved by a stepping roll method using a shaft for moving the processing unit, thereby piercing the groove. In addition, when moving intermittently, the processed part is retracted so that the processed part does not hit the insulating substrate.

  According to the thin film solar cell of the present invention, the photoelectric conversion layer is either an amorphous semiconductor, an amorphous semiconductor containing microcrystals, or a compound (chalcopyrite) solar cell.

Moreover, according to the manufacturing method of the thin film solar cell of this invention, the said insulating substrate is formed from the film material.
Moreover, according to the manufacturing method of the thin film solar cell of this invention, the said film material is a heat resistant film of a polyimide, a polyamideimide, or a polyethylene naphthalate.

  According to the thin film solar cell according to the present invention, the transparent electrode is separated around the second through-hole by using a blade, so that the effective area of the transparent electrode layer is increased and the output of the thin film solar cell is increased. Can be made.

  By adopting this configuration, the processing groove can be easily stopped at the back electrode portion. Furthermore, a short circuit due to thermal damage of the photoelectric conversion layer as in the case of forming a processing groove with a laser beam can also be prevented.

  Moreover, according to the thin film solar cell of the present invention, since the insulating substrate is formed of a film material, a method of transporting the insulating substrate with a transporting roll (for example, a roll-to-roll method, a stepping roll method) The thin film solar cell can be efficiently manufactured.

  In addition, according to the method for manufacturing a thin film solar cell of the present invention, since the transparent electrode is separated so as to surround the second through-hole, the transparent electrode and the back electrode are insulated. It is not necessary to perform mask processing in the vicinity of the second through hole, and the power generation area expansion effect at the time of manufacturing the thin film solar cell is improved. In addition, since it is not necessary to perform mask processing in the vicinity of the second through hole, the mask and the layer on the substrate do not come into contact with each other and the layer on the substrate is not damaged. Thereby, leak current does not increase in the thin film solar cell, and the defect rate when manufacturing the thin film solar cell can be reduced.

In addition, since the transparent electrode is separated around the second through hole and the transparent electrode layer and the back electrode layer under the power generation region are separated, the insulating property in the second through hole can be ensured.
By using a blade for processing, the groove can be stopped up to the power generation layer, and damage to the power generation layer due to heat can be suppressed.

  Moreover, in order to isolate | separate the circumference | surroundings of a hole, it is good to process by rotating a blade body around an axis | shaft. Furthermore, the machining time can be shortened by rotating a blade tool provided with a plurality of blades around the same axis.

The machining time can also be shortened by providing a plurality of blade tools.
In addition, drilling a large number of grooves in a shorter time can be achieved by intermittently moving a processing unit equipped with a plurality of blade tools by a stepping roll method using a shaft for moving the processing unit. It becomes possible to do.

It is a top view of the thin film solar cell concerning a 1st embodiment of the present invention. (A) is the sectional view on the AA line of FIG. 1, (b) is an enlarged view of C in (a). (A) is the BB sectional drawing of FIG. 1, (b) is an enlarged view of D in (a). It is a flowchart at the time of manufacturing the thin film solar cell which concerns on embodiment of this invention. It is a top view of the conventional thin film solar cell. (A) is the sectional view on the AA line of FIG. 5, (b) is an enlarged view of C in (a). (A) is the BB sectional drawing of FIG. 5, (b) is an enlarged view of D in (a). It is a perspective view which shows the blade tool provided with two or more blade bodies. It is a perspective view which shows the process part provided with the some blade body tool.

Hereinafter, a thin film solar cell according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a plan view of the thin-film solar cell according to the first embodiment. 2 is a cross-sectional view taken along the line AA in FIG. 1, and (b) is an enlarged view of C in (a). 3 is a cross-sectional view taken along line BB in FIG. 1, and (b) is an enlarged view of D in (a).
[First Embodiment]
As shown in FIGS. 1 and 2, the thin-film solar cell 1 according to this embodiment includes an insulating substrate 2. This insulating substrate 2 is made of a film material, for example, a material such as polyimide, polyamideimide, polyethylene naphthalate, or aramid.

  As shown in FIG. 2, on the surface 2a of the insulating substrate 2, a back electrode layer 3a made of metal and having a Mo layer at least partially such as Mo / Ag / ZnO is formed. A back electrode layer 3b made of Ag, Ag / ZnO, Al / ZnO, or the like is formed on the opposite surface 2b. In the case where the back electrode layer 3a is made only of molybdenum, the thickness thereof needs to be designed based on the required resistance, but is 0.1 μm to 1.0 μm. However, when a part of molybdenum is selenized like a CIGS solar cell, the thickness of the selenized part is about 0.2 μm, so the thickness of the molybdenum electrode is 0.3 μm to 1 μm. .About 2 μm. When the metal electrode layer 3a is made of Mo / Ag / ZnO or the like, in the case of a CIGS solar cell, the total thickness is 0.5 μm to 1.0 μm, and the thickness of the molybdenum portion in that case is 0.3 μm to 0.00 μm. 5 μm. Since the selenized portion of the molybdenum layer is weak in strength, it is removed by the blade body 12. When the solar cell is not CIGS, the metal electrode layer 3a has a total thickness of 0.3 μm to 1.0 μm and a molybdenum portion thickness of 0.1 μm to 0.3 μm.

In the following examples, a case will be described in which the back surface electrode has a molybdenum layer in all regions of the thin film solar cell as viewed in a plan view.
As shown in FIG. 2, the photoelectric conversion layer 4 and the transparent electrode layer 5 are laminated in this order on the back electrode layer 3 a on the one surface 2 a of the insulating substrate 2. Here, as the photoelectric conversion layer 4, an amorphous semiconductor, a compound semiconductor, a dye-sensitized solar cell, or an organic solar cell can be used.

On the other hand, the second back electrode layer 6 is laminated on the first back electrode layer 3 b on the other surface 2 b of the insulating substrate 2.
As shown in FIG. 1, the layers (back electrode layer 3a, photoelectric conversion layer 4, transparent electrode layer 5) laminated on one surface 2a of the insulating substrate 2 are formed by a first patterning line 9 by laser processing. It is divided into multiple parts.

  Further, as shown in FIGS. 1 and 3, the layers (first back electrode layer 3b and second back electrode layer 6) laminated on the other surface 2b of the insulating substrate 2 are similarly laser processed. The second patterning line 10 is divided into a plurality of parts. Here, the first patterning lines 9 and the second patterning lines 10 are alternately arranged on the insulating substrate 2.

  As shown in FIGS. 1 and 2, the insulating substrate 2 is provided with a first through hole 7 that penetrates the insulating substrate 2. The transparent electrode layer 5 and the second back electrode layer 6 are connected so as to overlap each other on the side wall portion 7 a of the first through hole 7. Thereby, the unit cell (unit solar cell) which consists of each layer on the one surface 2a of the insulating substrate 2 and each layer on the other surface 2b is formed.

  As shown in FIGS. 1 and 3, the insulating substrate 2 is provided with a second through hole 8 that penetrates the insulating substrate 2. The back electrode layer 3 a and the first back electrode layer 3 b are electrically connected via the side wall 8 a of the second through hole 8. That is, adjacent unit cells are electrically connected by the second through hole 8. Specifically, the first and second through holes 7 and 8 are formed by the first and second back electrode layers 3b and 6 → the first through hole 7 → the transparent electrode layer 5 → the photoelectric conversion layer 4 → the back electrode layer. It is used for connecting in the order of 3a → second through hole 8 → first back electrode layer 3b.

As described above, the thin film solar cell 1 having the SCAF structure is configured by electrically connecting adjacent unit cells in series.
As a feature of the present embodiment, as shown in FIG. 3, the power generation portion of the transparent electrode 5 is separated by a separation groove 11 formed by the blade body 12 around the second through hole 8.

From the above configuration, the transparent electrode layer 5 and the second back electrode layer 6 are electrically insulated by the separation groove 11 provided in the transparent electrode 5 around the second through hole 8.
Next, the manufacturing method of the thin film solar cell which concerns on embodiment of this invention is demonstrated with reference to drawings. FIG. 4 is a flowchart when manufacturing the thin-film solar cell 1 according to this embodiment.

  The thin film solar cell 1 according to this embodiment uses the film material as described above as the insulating substrate 2. As a method for manufacturing the thin-film solar cell 1, a roll-to-roll method or an ink jet printing technique is used. For example, the roll-to-roll method is a method in which a film material substrate is conveyed by a plurality of rolls (conveying means), and a thin film is continuously formed on the substrate in a film forming chamber that is continuously arranged.

  When the thin film solar cell 1 is manufactured, as shown in FIG. 4, first, in step S1, the insulating substrate 2 is pretreated. Specifically, pretreatment such as cleaning the surface by exposing the insulating substrate 2 to plasma is performed.

  Next, in step S <b> 2, the second through hole 8 is formed in the insulating substrate 2. The second through hole 8 is formed by punching (a perforating method). The shape of the second through hole 8 is a circle having a diameter of 1 mm. The second through-hole 8 has a circular diameter in the range of 0.05 to 1 mm, and the number of perforations can be adjusted according to the design.

  Next, in step S3, a back electrode layer 3a and a first back electrode layer 3b are formed on both surfaces 2a and 2b of the insulating substrate 2 by performing a sputtering process. At this time, the back electrode layer 3 a and the first back electrode layer 3 b are electrically connected through the second through hole 8.

  Thereafter, in step S4, the layer formed on the light receiving surface side of the insulating substrate 2 is linearly removed by laser processing to form a primary patterning line (not shown). At this time, the lines formed on both surfaces 2a and 2b of the insulating substrate 2 are formed so as to be shifted from each other.

In step S <b> 5, the first through hole 7 is formed in the insulating substrate 2. The first through hole 7 is formed by punching.
In step S6, the photoelectric conversion layer 4 is formed on the back electrode layer 3a of the insulating substrate 2, and then in step S7, the transparent electrode layer 5 is further formed on the photoelectric conversion layer 4.

Next, in step S <b> 8, the second back electrode layer 6 is formed on the first back electrode layer 3 b of the insulating substrate 2.
Next, in step S9, the photoelectric conversion layer 4 and the transparent electrode layer 5 on the primary patterning line formed in step S4 are removed again linearly by laser processing to form the first patterning line 9.

Further, in step S10, the second back electrode layer 6 is linearly removed by laser processing to form a second patterning line 10. The first patterning line and the second patterning line are formed alternately.
Further, in step S11, the transparent electrode formed in step S7 is separated by the blade body 12 around the second through hole formed in step S2, so that the transparent electrode and the electrode outside the portion surrounded by the separation groove 11 are separated. 3 is separated, and the layers on the insulating substrate 2 are separated into a plurality of unit cells by the first and second patterning lines 9 and 10, and the series connection of the thin-film solar cells 1 is completed.
Processing of the separation groove 11 by the blade body 12 will be described with reference to FIGS.
The width of the groove 11 formed around the second through hole by the blade body 12 is 30 to 100 μm. The width of the blade edge of the blade body 12 is about the same as this width.
Since this groove is provided so as to surround the periphery of the through hole, the machining is preferably performed by rotating around the axis of the blade tool 13. Furthermore, as shown in FIG. 8, a plurality of blade bodies 12 (in the example of FIG. 8, the blade tool 13 is provided with three blade bodies 12 on the circumference) around the same axis. By providing the provided blade tool 13, the processing speed can be increased.

Further, as shown in FIG. 9, by providing the processing portion 14 provided with a plurality of blade tools 13, the processing speed can be further improved, and a plurality of grooves can be formed at a time.
In FIG. 9, there is a processing unit 14 including a plurality of blade tools 13, and the processing unit 14 is configured to be moved by a moving shaft 15 of the processing unit. Therefore, if the shaft 15 for movement of this processing part is driven intermittently (stepping roll method), the piercing groove can be continuously formed around the second through hole.

  According to the thin film solar cell according to the first embodiment of the present invention, the transparent electrode layer 5 is divided by the blade body 12 around the second through-hole 8 by the blade body 12, so that Use of a laser or a mask becomes unnecessary, and the effective power generation area of the thin film solar cell is improved. Since this structure contains molybdenum in at least a part of the back electrode 3a, it is particularly useful for CIGS solar cells and CIS thin film solar cells.

  In the case of an amorphous thin film solar cell or the like, the back electrode 3a may be formed of a molybdenum layer only in a portion around the second through-hole 8 when viewed in plan view. It is difficult to form a molybdenum layer.

According to the method for manufacturing the thin-film solar cell 1 according to the first embodiment of the present invention, since the transparent electrode layer 5 includes the step of separating the transparent electrode layer 5 around the through-hole 8 by the blade body 12, It is not necessary to perform mask processing in the vicinity of the through hole, and the yield at the time of manufacturing the thin film solar cell 1 is improved. Since this method also contains molybdenum in at least a part of the back electrode, it is particularly useful in a method for manufacturing a CIGS solar cell.
In addition, since it is not necessary to perform mask processing in the vicinity of the second through-hole 8, the mask and the layer on the insulating substrate 2 do not come into contact with each other and the layer on the insulating substrate 2 is not damaged. Thereby, the leakage current does not increase in the thin film solar cell 1, and the defect rate when the thin film solar cell 1 is manufactured can be reduced.

  In the present invention, since the blade body 12 is scanned around the second through hole, damage due to heat of the surrounding layers is suppressed, and further, the blade body 12 stops in hard molybdenum having a Vickers hardness of 1530 MPa. Therefore, there is an advantage that it can be easily processed.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications and changes can be made based on the technical idea of the present invention.

DESCRIPTION OF SYMBOLS 1 Thin film solar cell 2 Insulating substrate 3 Metal electrode layer 3a Back surface electrode layer 3b 1st back surface electrode layer 4 Photoelectric conversion layer 5 Transparent electrode layer 6 2nd back surface electrode layer 7 1st through-hole 8 2nd through-hole 9 1st patterning line 10 2nd patterning line 11 Groove 12 Blade body 13 Blade body tool 14 Processing part 15 Shaft for movement of processing part

Claims (8)

On one surface of the insulating substrate, a back electrode layer containing at least part of molybdenum, a photoelectric conversion layer, and a transparent electrode layer are laminated in this order, and the other surface of the insulating substrate has a first electrode A back electrode layer and a second back electrode layer are stacked in this order, and the insulating substrate is formed into a plurality of unit cells by alternately forming patterning lines on the layers stacked on both sides of the insulating substrate. The transparent electrode layer and the second back electrode layer are electrically connected via a first through hole penetrating the insulating substrate, and the back electrode layer and the first back electrode are divided. In a thin film solar cell in which layers are electrically connected via a second through hole penetrating the insulating substrate, and adjacent unit cells are connected in series,
The transparent electrode layer around the second through hole is separated by a groove formed by scanning a blade, and the transparent electrode layer and the second back electrode layer are electrically insulated. A thin film solar cell characterized by Forming a second through hole in the insulating substrate;
Forming a back electrode layer containing molybdenum at least in part on one surface of the insulating substrate, and forming a first back electrode layer on the other surface of the insulating substrate;
After forming the back electrode layer and the first back electrode layer, forming a first through hole in the insulating substrate;
Laminating a photoelectric conversion layer and a transparent electrode layer in this order from one surface side of the insulating substrate, and laminating a second back electrode layer from the other surface side of the insulating substrate;
Alternately forming patterning lines on the layers laminated on both sides of the insulating substrate, dividing the insulating substrate into a plurality of unit cells, and scanning at least the transparent electrode layer with a blade, Dividing the transparent electrode layer around the second through hole to electrically insulate the transparent electrode from the second back electrode;
The manufacturing method of the thin film solar cell characterized by including.   3. The method for manufacturing a thin-film solar cell according to claim 2, wherein the transparent electrode layer is separated by rotating the blade around an axis.   The method for producing a thin-film solar cell according to claim 2 or 3, wherein the transparent electrode layer is separated using a blade tool having a plurality of blades around the same axis.   5. The method for manufacturing a thin-film solar cell according to claim 4, wherein a processing unit including a plurality of the blade tools is provided for processing.   The method for manufacturing a thin-film solar cell according to any one of claims 2 to 5, wherein the insulating substrate is formed of a film material.   The method for producing a thin-film solar cell according to claim 6, wherein the film material is a heat-resistant film of polyimide, polyamideimide, or polyethylene naphthalate. A blade tool provided with a plurality of blade bodies around the center of the shaft, a processing unit provided with a plurality of the blade tool, and a shaft for moving the processing unit provided with the processing unit, 3. The thin-film solar cell according to claim 2, wherein a groove is provided around the second through hole provided in the thin-film solar cell by intermittently moving the moving shaft of the processed portion. Method.

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