WO2013108623A1

WO2013108623A1 - Method for manufacturing integrated solar cell

Info

Publication number: WO2013108623A1
Application number: PCT/JP2013/000190
Authority: WO
Inventors: 栄郎矢後
Original assignee: 富士フイルム株式会社
Priority date: 2012-01-18
Filing date: 2013-01-17
Publication date: 2013-07-25
Also published as: JP2013149697A; TW201340364A

Abstract

[Problem] To provide a method for manufacturing a thin-type solar cell with higher production efficiency, which is capable of producing an integrated structure having higher power generation efficiency via less processes. [Solution] A first electrode layer (12) is formed on a substrate (10) and a separation groove (21) exposing the surface of the substrate (10) at the bottom portion thereof is formed through the first electrode layer (12). A laminated body (S) is formed by sequentially laminating a photoelectric conversion layer (13) and a second electrode layer (16) so as to cover the first electrode layer (12) and the surface of the substrate (10) exposed through the separation groove (21). An opened groove (22) having a depth of reaching the surface position of the first electrode layer (12) is formed parallel to the separation groove (21). The opened groove (22) is formed in such a manner that a portion (24) of the laminated body (S) remains separated from both walls (α,β). A connection portion (40) is formed to electrically connect mutually adjoining photoelectric conversion elements across the opened groove (22).

Description

Manufacturing method of integrated solar cell

The present invention relates to a method for manufacturing a thin-film solar cell having an integrated structure, and in particular, an integrated solar cell that can form an integrated structure that is excellent from the viewpoint of power generation efficiency and production efficiency in a small number of steps and that has excellent production efficiency Regarding the method.

A photoelectric conversion element having a laminated structure of a lower electrode (back surface electrode), a photoelectric conversion semiconductor layer that generates charges by light absorption, and an upper electrode is used for applications such as solar cells.

Conventionally, Si-based solar cells using bulk single-crystal Si or polycrystalline Si, or thin-film amorphous Si have been mainstream, but research and development of compound semiconductor solar cells that do not depend on Si have been made. Compound semiconductor solar cells include CIS (Cu-In-Se) or CIGS (Cu-In-Ga-Se), which is composed of a bulk system such as a GaAs system, and a group IB element, group IIIB element and group VIB element. And other thin film systems are known. The CIS system or CIGS system is reported to have a high light absorption rate and high energy conversion efficiency.

In order to increase the output of the solar cell, it is necessary to integrate a plurality of photoelectric conversion elements (solar cell) connected in series on a single substrate.

As a method for integrating compound semiconductor solar cells, a method of performing a three-stage scribe process is well known. In this method, as shown in FIG. 16A, after the electrode layer 112 is formed on the insulating substrate 110, the electrode layer 112 is scribed to form the first separation groove P1, and as shown in FIG. 16B. Then, a photoelectric conversion layer 113, a buffer layer 114, and a window layer 115 are sequentially formed to form a separation groove P2 penetrating therethrough and reaching the surface of the electrode layer 112. As shown in FIG. A layer (upper electrode) 116 is formed, and a separation groove P3 extending from the upper electrode 116 to the surface of the lower electrode layer is formed. In this way, an integrated structure is formed in which adjacent cells are separated by the separation groove P3 and adjacent cells are connected in series by the light-transmitting conductive layer material embedded in the separation groove P2.

In such an integrated structure, since the first separation groove P1 to the third separation groove P3 are necessary, it is necessary to increase the distance between the cells necessary for connecting the solar battery cells. There is a problem that the power generation efficiency of the system is reduced. Therefore, other integration methods have been proposed (for example, Patent Documents 1, 2, and 3).

Patent Document 1 discloses a method for manufacturing an integrated photoelectric conversion device in which a base electrode, a photoelectric conversion layer, and a transparent electrode are collectively formed on a substrate, and three scribing operations each having a different depth are collectively performed. ing. This Patent Document 1 describes that batch film formation and batch scribing are simpler than the method of performing scribing for each layer, and the number of steps can be reduced, so that the time required for manufacturing can be shortened. Has been.

Patent Document 2 discloses a method in which a base electrode, a photoelectric conversion layer, and a transparent electrode are collectively formed on a substrate, and then a single scribe process is performed. In Patent Document 2, in the scribing process, one groove portion having a narrow groove for separating the base electrode is formed at the bottom, and then one side wall of the groove portion and the narrow groove for separating the base electrode are insulated. A method of depositing a body and connecting conductors thereon to electrically connect cells is disclosed. Thus, it is disclosed that the distance between cells necessary for connection can be shortened and the power generation efficiency per unit area can be increased.

In Patent Document 3, after forming a plurality of transparent electrodes having a predetermined shape on a substrate, a photoelectric conversion layer and an electrode layer are formed, and then a connection groove and an insulation groove are formed by laser beam irradiation. A method of manufacturing an integrated solar cell by filling a conductive paste into a conductive paste and forming a connection portion is disclosed.

JP 2001-7359 A Special table 2009-512197 JP 61-50381 A

However, in Patent Document 1, since three grooves are formed, it is difficult to shorten the distance between the cells, and the power generation efficiency cannot be increased.
In Patent Document 2, it seems that the distance between the cells can be shortened because there is one groove. However, since the photosensitive polymer (insulating ink) used for forming the insulator is actually widened, the scribe is performed. Need to be wide. For this reason, the area of the cell per unit area becomes small, and sufficient power generation efficiency cannot be improved.

In addition, when a metal electrode such as Mo is used as the lower electrode layer as in the CIGS system, and the deposition of the photoelectric conversion layer is performed at a high temperature, the hardness of the lower electrode increases due to thermal history. When the lower electrode layer is scribed after deposition of the photoelectric conversion layer as in 1 and 2, it is necessary to irradiate a high-power laser beam, which may damage the substrate under the lower electrode layer.

The integrated structure described in Patent Document 3 has a structure in which a conductive material is in contact with the cross section of the photoelectric conversion layer and the upper electrode, which causes current leakage in the photoelectric conversion layer and reduces power generation efficiency.

This invention is made | formed in view of the said situation, and it aims at providing the manufacturing method of the integrated solar cell excellent in production efficiency which can form the integrated structure excellent in power generation efficiency with few processes. Is.

The present invention is a method for manufacturing an integrated solar cell, wherein a plurality of photoelectric conversion elements are arranged on a substrate and connected in series,
Forming a first electrode layer on a substrate having at least an insulating surface;
Forming a separation groove in which the surface of the substrate is exposed at the bottom of the first electrode layer to separate the first electrode layer into a plurality of regions;
A photoelectric conversion layer and a second electrode layer are sequentially laminated so as to cover the surface of the substrate exposed to the first electrode layer and the separation groove, thereby forming a laminate.
A part of the stacked body is an opening groove part having a depth parallel to the separation groove and reaching the surface position of the first electrode layer, and spaced from both walls of the groove part in the groove width direction of the opening groove part. Forming the remaining open groove,
A connecting portion that electrically connects the second electrode layer of one of the photoelectric conversion elements adjacent to each other across the opening groove and the first electrode layer of the other element is connected to the opening groove. It is formed by dropping conductive ink from the part of the laminate to the one element side.

Furthermore, it is preferable to form a covering insulating portion that covers the connecting portion.

In the connection portion forming step, it is preferable that the part of the stacked body is used as a stopper portion that suppresses spreading of the conductive ink to the other element side.

Before forming the connecting portion, an insulating portion extending in the height direction of the wall surface is formed on at least a part of the wall surface on the one element side of the opening groove portion,
It is preferable that the connecting portion is formed on the insulating portion.

The separation groove is preferably formed by laser scribe.

It is preferable that the opening groove is formed by mechanically scribing two grooves at a predetermined interval so that a part of the laminated body remains in a region to be the opening groove.

It is preferable that the connecting portion is formed by dropping the conductive ink by an ink jet method.

According to the method for manufacturing an integrated solar cell of the present invention, after forming the first electrode layer and before laminating the photoelectric conversion layer or the like, the first electrode layer is divided into a plurality of regions by forming separation grooves. Therefore, even when a material such as a photoelectric conversion layer that is cured by thermal history is used for the first electrode layer, it is relatively small because it is in a state before receiving the thermal history. Separation grooves can be formed with power.

After the first electrode layer is separated, the opening groove is formed after the photoelectric conversion layer and the second electrode layer are formed, so that an integrated structure can be manufactured with few steps, and excellent production efficiency can be obtained. Can be realized.

It is typical sectional drawing which shows the integrated solar cell manufactured with the manufacturing method of the 1st Embodiment of this invention. It is a schematic plan view of the principal part of the integrated solar cell shown in FIG. It is a schematic plan view of the principal part of the modification of the integrated solar cell manufactured with the manufacturing method of the 1st Embodiment of this invention. It is typical sectional drawing which shows the manufacturing method of embodiment to process order. It is typical sectional drawing which shows the manufacturing method of the 1st Embodiment of this invention to process order. It is typical sectional drawing which shows the integrated solar cell manufactured with the manufacturing method of the 2nd Embodiment of this invention. It is a schematic plan view of the principal part of the integrated solar cell shown in FIG. It is a schematic plan view of the principal part of the modification of the integrated solar cell manufactured with the manufacturing method of the 2nd Embodiment of this invention. It is typical sectional drawing which shows the manufacturing method of the 2nd Embodiment of this invention to process order. It is typical sectional drawing which shows the deformability of the manufacturing method of the 2nd Embodiment of this invention. It is typical sectional drawing which shows the integrated solar cell manufactured with the manufacturing method of the 3rd Embodiment of this invention. It is a schematic plan view of the principal part of the integrated solar cell shown in FIG. It is a schematic plan view of the principal part of the modification of the integrated solar cell manufactured with the manufacturing method of the 3rd Embodiment of this invention. It is typical sectional drawing which shows the manufacturing method of the 3rd Embodiment of this invention to process order. It is typical sectional drawing which shows the deformability of the manufacturing method of the 3rd Embodiment of this invention. It is typical sectional drawing which shows the manufacturing method of the conventional integrated solar cell in order of a process.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

“First Embodiment”
FIG. 1 is a schematic cross-sectional view showing an integrated solar cell 1 manufactured by the manufacturing method of the first embodiment of the present invention. FIG. 2 is a schematic plan view of the main part of the integrated solar cell 1 shown in FIG. 1, and FIG. 3 is a schematic plan view of the main part of a modification of the integrated solar cell of the present embodiment.

As shown in FIG. 1 and FIG. 2, the integrated solar cell 1 includes a substrate 10 whose surface layer is an insulating layer 10a and an insulating layer 10a of the substrate 10, with a line-shaped opening groove 22 interposed therebetween. A plurality of solar cells (photoelectric conversion elements) 20a to 20d electrically connected in series in the longitudinal direction L of the tenth, a first conductive member 50 connected to the solar cell 20a at one end, And a second conductive member 52 connected to the solar battery cell 20d at the other end.

The solar cells 20a to 20d are separated by the opening groove 22, and the back electrode layer 12, which is the first electrode layer, the photoelectric conversion layer 13, the buffer layer 14, and the transparent electrode layer 16 which is the second electrode layer. Have. In each of the solar cells 20a to 20b, the conductive layer 40 is formed as a connection portion for electrically connecting the transparent electrode of one cell of the cells adjacent to each other with the opening groove 22 interposed therebetween and the back electrode of the other cell. Thus, adjacent cells are connected in series and integrated. For example, in the solar battery cell 20a and the solar battery cell 20b, the transparent electrode layer 16 of the solar battery cell 20a and the back electrode layer 12 of the solar battery cell 20b are electrically connected by the conductive layer 40.
A covering insulating portion 42 is formed so as to cover the conductive layer 40.

In the present embodiment, for convenience, four solar cells 20a to 20d are described as an example connected in series, but the number of connected solar cells is not particularly limited. Further, in the solar battery cell, it is not necessarily provided depending on the configuration of the buffer layer 14 and the photoelectric conversion layer 13. Further, a window layer (insulating layer) may be provided between the buffer layer 14 and the transparent electrode layer 16.

As shown in FIG. 2, the substrate 10 of the present embodiment has its shape, size, and the like determined as appropriate according to the size of the integrated solar cell 1 to be applied. For example, the length of one side A rectangular shape or a rectangular shape with a length exceeding 1 m.
The solar cells 20a to 20d and the first and second

conductive members

50 and 52 are formed in a strip shape extending long in the width direction W (extending direction) perpendicular to the longitudinal direction L (arrangement direction) on the substrate 10. Is formed.

The back electrode layer 12 is separated from adjacent back electrode layers 12 by a plurality of separation grooves 21 provided in the longitudinal direction L of the substrate 10 at predetermined intervals. The separation groove 21 is a groove reaching the surface of the substrate 10 (insulating layer 10a), and its width is, for example, 50 μm. The photoelectric conversion layer 13 is embedded in the separation groove 21.

The opening groove portion 22 is formed in parallel to the separation groove 21 and at a depth that is substantially the surface position of the back electrode layer 12. Further, in the groove width direction of the opening groove portion 22, both the walls α and β of the groove portion are stacked, that is, at positions separated from the wall surface α of one cell 20a and the wall surface β of the other cell 20b of the cells adjacent to each other across the groove portion. A part of the body, here, part of the photoelectric conversion layer 13 is left as a stopper part 24 described later. In other words, the opening groove portion 22 includes the stopper portion 24 and two concave portions (grooves) 22a and 22b that sandwich the stopper portion 24. The width of the opening groove is, for example, 50 μm to 100 μm.

The opening groove 22 is formed at a position where the back electrode of one cell 20a is not exposed to the first groove 22a and the back electrode of the other cell 20b is at least partially exposed to the first groove 22a. ing. At this time, it is preferable that the separation groove 21 at least partially overlaps the position of one wall surface α of the opening groove portion 22. The separation groove 21 may be located on the one cell 20a side (under one cell 20a) from the wall surface α, but in order to suppress a loss portion that does not contribute to photoelectric conversion, the separation groove 21 is located near the wall surface α. It is hoped that

The stopper portion 24 is located on the back electrode layer 12 of the other cell 20b to which the conductive layer 40 is connected to the back electrode layer 12, and the back electrode layer 12 has one of the back electrode layers 12 so as to contact the conductive layer 40. It is necessary to be exposed to the bottom part by the side of the recessed part 22a.

As shown in FIG. 2, the conductive layer 40 is formed over the entire width direction W of the substrate 10 of the solar battery cell 20a. Further, the covering insulating portion 42 is also formed over the entire width direction W of the substrate 10 so as to cover the conductive layer 40.

Note that the solar cells 20a to 20d need only be electrically connected in series, and the conductive layer 40 may not be formed over the entire width direction W of the substrate 10. In order to electrically connect the solar cells 20a to 20d in series, it is sufficient that the solar cells 20a to 20d are connected at least partially using the conductive layer 40 in the width direction W. For example, as shown in FIG. For example, three conductive layers 40a may be formed in the width direction W with respect to the cell 20a, and the covering insulating portion 42a may be formed so as to cover each conductive layer 40a.

The first conductive member 50 and the second conductive member 52 arranged at both ends of the solar cells connected in series are for taking out the electric power generated in the solar cells to the outside.

The first conductive member 50 and the second conductive member 52 are, for example, strip-shaped members that extend substantially linearly in the width direction of the substrate 10 and are connected to the right-side or left-end back electrode layer 12 respectively. Has been. As shown in FIG. 1, the first conductive member 50 and the second conductive member 52 are, for example,

copper ribbons

50a and 52a covered with covering

materials

50b and 52b of indium copper alloy. The first conductive member 50 and the second conductive member 52 are connected to the back electrode layer 12 by ultrasonic solder, a conductive adhesive, a conductive tape, or the like.
The first conductive member 50 and the second conductive member 52 may be tin-plated copper ribbons.

In the integrated solar cell 1 having this configuration, when light is incident on the solar cells 20a to 20d from the transparent electrode layer 16 side, the light passes through the transparent electrode layer 16 and the buffer layer 14, and the photoelectric conversion layer 13 An electromotive force is generated, and for example, a current from the transparent electrode layer 16 toward the back electrode layer 12 is generated. The electric power generated in the integrated solar cell 1 can be taken out of the solar cell 1 from the first conductive member 50 and the second conductive member 52. In the present embodiment, the first conductive member 50 is a negative electrode and the second conductive member 52 is a positive electrode. However, the first conductive member 50 and the second conductive member 52 have opposite polarities. It may be appropriately changed depending on the layer configuration, connection configuration, and the like of the solar cells 20a to 20d.

Hereinafter, the manufacturing method according to the first embodiment will be described with reference to FIGS. 4 and 5 are partial schematic cross-sectional views showing the manufacturing process, and show the main part of the integrated structure including the

partial cells

20a and 20b and the opening groove between them.

First, a substrate 10 having a predetermined size and having an insulating surface is prepared. The substrate 10 is, for example, provided with an anodized film 10a on the surface of an aluminum base material.

As shown to a of FIG. 4, the back surface electrode layer 12 is formed in the surface of the board | substrate 10 as a 1st electrode layer.
Next, as shown in FIG. 4b, a separation groove 21 in which the surface of the substrate 10 is exposed at the bottom is formed in the back electrode layer 12, and the back electrode layer 12 is separated into a plurality of regions. The separation groove 21 is preferably formed by laser scribing.
Since the separation groove 21 is formed before the back electrode layer 12 receives the thermal history, the scribing can be performed with a relatively low power even when the back electrode layer is made of a material that is cured by a thermal history such as Mo. it can. When a laser is used, there is a problem that the substrate is damaged when a relatively large power is used. However, the manufacturing method of the present invention does not cause a problem that the substrate is damaged.

Next, as shown in FIG. 4 c, the photoelectric conversion layer 13, the buffer layer 14, and the second electrode layer are transparent so as to cover the surface of the substrate 10 exposed at the bottoms of the back electrode layer 12 and the separation groove 21. The electrode body 16 is sequentially laminated to form a laminate S.
Thus, since a scribe process is unnecessary during the lamination process of the photoelectric conversion layer 13 to the transparent electrode layer 16, production efficiency can be improved without complicating the manufacturing process.

Next, as shown in FIG. 5d, an opening groove 22 having a depth parallel to the separation groove 21 and reaching the surface position of the back electrode layer 12 is formed. At this time, the opening groove portion 22 is formed so as to leave a part 24 of the stacked body S at a position spaced from both walls α and β of the opening groove portion 22 in the groove width direction of the opening groove portion 22. For example, two recesses (grooves) 22a and 22b having a depth reaching the surface position of the back electrode layer 12 from above the stacked body S at a predetermined interval are formed by laser or mechanical scribing at a desired opening groove forming position. Thus, the opening groove portion 22 in which a part 24 of the stacked body S is left between the two

grooves

22a and 22b can be formed. The back electrode layer 12 is exposed in the first and

second grooves

22 a and 22 b sandwiching the part 24 of the laminated body of the formed opening groove 22, and is partially embedded in the separation groove 21. The photoelectric conversion layer 13 is exposed. Here, the opening groove portion formation position is controlled so that the back electrode layer 12 of the cell 20a having the one wall surface α of the opening groove portion 22 is not exposed to the first groove 22a.

In the present embodiment, the photoelectric conversion layer 13 is left as a part 24 of the laminated body in the opening groove 22, and the buffer layer 14 and the transparent electrode layer are included in the part 24. 16 may remain.

Next, as illustrated in e of FIG. 5, for example, by using an inkjet method, the conductive ink (conductive paste) that becomes the conductive layer 40 is first applied from the transparent electrode layer 16 of one solar battery cell 20 a to the first. The droplets are ejected in a range extending to the back electrode layer 12 of the other solar battery cell 20b in the groove 22a. In this case, since the conductive ink is ejected into the first groove 22a, the conductive ink is restrained by the stopper portion 24 and is prevented from spreading toward the second groove 22b. That is, the conductive ink is prevented from contacting the wall surface β of the other solar battery cell 20b. In addition, since the back electrode layer 12 of one cell 20a is not exposed in the first groove 22a, a short circuit between the

adjacent cells

20a and 20b is prevented.
After the conductive ink is ejected, a heat curing process and a light curing process are performed according to the conductive ink. Thereby, the conductive layer 40 as a conductive connection portion is formed.

Next, the coating insulating part 42 is formed so as to cover the conductive layer 40. For example, using an ink jet method, an insulating ink is ejected onto the conductive layer 40, and a heat curing process or a light curing process according to the insulating ink is performed. Thereby, the film insulation part 42 is formed.
The film insulating part 42 only needs to be formed so as to cover the conductive layer 40, but in the present embodiment, the film insulating part 42 extends beyond the stopper part 24 and part of the second groove 22 b. Furthermore, the coating insulating part 42 may be filled in the entire opening groove part 22.

Note that the coating insulating portion 42 is not necessarily provided. However, when a paste containing metal particles is used as the conductive ink, the migration of the metal particles can be prevented by covering the conductive layer 40 with the coating insulating portion 42, thereby preventing the efficiency from being lowered due to the migration. Can do. In particular, when the metal particles are silver (Ag), the occurrence of migration is remarkable, and the effect of preventing the reduction in efficiency is high by preventing migration. Therefore, it is preferable to use an insulating material having an effect of preventing migration.
In addition, the coating insulating part 42 can more reliably prevent a short circuit between adjacent cells.

As described above, an integrated solar cell 1 in which a plurality of solar cells 20a to 20d are connected as shown in FIG. 1 can be manufactured.

In the integrated solar cell 1 manufactured by the manufacturing method of the present embodiment, the cells are connected by the opening groove 22, so that the solar cell per unit area is compared with the integrated solar cell having three separation grooves. The power generation efficiency can be improved by increasing the area of the battery cell. In particular, since the opening groove portion 22 is provided with the stopper portion 24 to suppress the spreading of the conductive ink, the width of the opening groove portion 22 can be shortened, and the power generation efficiency per unit area can be further improved. .

Further, in the manufacturing method of the present embodiment, after the scribing process of the back electrode, the stacked body S having other layers constituting the solar battery cell is continuously formed, and the opening groove portion 22 and the stopper portion 24 are formed. By separating the solar cells and electrically connecting the solar cells, an integrated structure can be realized in a relatively small number of steps, compared with the case where the three scribe steps shown in FIG. 16 are required. Thus, the production efficiency can be increased. In addition, since the back electrode is scribed before the photoelectric conversion layer is formed, power necessary for scribing the back electrode can be suppressed, and damage to the substrate due to high output power can be prevented. Yield can be improved.

“Second Embodiment”
FIG. 6 is a schematic cross-sectional view showing an integrated solar cell 2 manufactured by the manufacturing method of the second embodiment of the present invention. FIG. 7 is a schematic plan view of the main part of the integrated solar cell 2 shown in FIG. 6, and FIG. 8 is a schematic plan view of the main part of Modification 2 ′ of the integrated solar cell of the present embodiment. is there.

As shown in FIG. 6 and FIG. 7, the integrated solar cell 2 includes a substrate 10 whose surface layer is an insulating layer 10 a and an insulating layer 10 a of the substrate 10, with a line-shaped opening groove 22 interposed therebetween. A plurality of solar cells (photoelectric conversion elements) 20a to 20d electrically connected in series in the longitudinal direction L of the tenth, a first conductive member 50 connected to the solar cell 20a at one end, And a second conductive member 52 connected to the solar battery cell 20d at the other end.

The solar cells 20a to 20d are separated by the opening groove 22, and the back electrode layer 12, which is the first electrode layer, the photoelectric conversion layer 13, the buffer layer 14, and the transparent electrode layer 16 which is the second electrode layer. Have. In each of the solar cells 20a to 20b, the conductive layer 40 is formed as a connection portion for electrically connecting the transparent electrode of one cell of the cells adjacent to each other with the opening groove 22 interposed therebetween and the back electrode of the other cell. Thus, adjacent cells are connected in series and integrated. For example, in the solar battery cell 20a and the solar battery cell 20b, the transparent electrode layer 16 of the solar battery cell 20a and the back electrode layer 12 of the solar battery cell 20b are electrically connected by the conductive layer 40.

In the present embodiment, the insulating portion 44 is formed so as to cover one wall surface α of the opening groove portion 22, and the conductive layer 40 is not in contact with the wall surface α by the insulating portion 44, and is on the cell side having the wall surface α. It is formed so as to be connected to the transparent electrode layer 16. In the present embodiment, since the conductive layer 40 does not contact the wall surface α, generation of internal leakage current of the solar battery cell having the wall surface α is prevented.

In the present embodiment, for convenience, four solar cells 20a to 20d are described as an example connected in series, but the number of connected solar cells is not particularly limited. In the solar battery cell, the buffer layer 14 is not necessarily provided depending on the configuration of the photoelectric conversion layer 13. Further, a window layer (insulating layer) may be provided between the buffer layer 14 and the transparent electrode layer 16.

As shown in FIG. 7, the substrate 10 of this embodiment has its shape, size, and the like determined as appropriate according to the size of the integrated solar cell 2 to be applied. For example, the length of one side A rectangular shape or a rectangular shape with a length exceeding 1 m.
The solar cells 20a to 20d and the first and second

conductive members

As shown in FIG. 6, the opening groove portion 22 is preferably formed so that the separation groove 21 is located on the wall surface α side of the stopper portion 24 from the vicinity of one wall surface α of the opening groove portion 22. The separation groove 21 may be located on the one cell 20a side (under one cell 20a) from the wall surface α, but in order to suppress a loss portion that does not contribute to photoelectric conversion, the separation groove 21 is located near the wall surface α. It is hoped that

The stopper part 24 should just be located on the back surface electrode layer 12 of the other cell 20b to which the conductive layer 40 is connected to the back surface electrode layer 12, or on the photoelectric conversion layer embedded in the separation groove 21. However, the back surface electrode layer 12 of the other cell 20b needs to be exposed in the recess 22b on the other wall surface β side of the stopper portion 24 in order to bring the conductive layer 40 into contact therewith.

As shown in FIG. 7, the insulating part 44 and the conductive layer 40 are formed over the entire width direction W of the substrate 10 of the solar battery cell 20a.

Note that it is only necessary that the solar cells 20 a to 20 d can be electrically connected in series, and the conductive layer 40 does not have to be formed over the entire width direction W of the substrate 10. In order to electrically connect the solar cells 20a to 20d in series, it is only necessary to connect at least part of the solar cells 20a to 20d using the conductive layer 40 in the width direction W. For example, as shown in FIG. For example, three conductive layers 40a may be formed in the width direction W with respect to the cell 20a.
Note that the insulating portion 44 may not be continuously formed in the width direction W as long as the conductive layer 40a is formed so as not to contact the wall surface α.

The first conductive member 50 and the second conductive member 52 are, for example, strip-shaped members that extend substantially linearly in the width direction of the substrate 10 and are connected to the right-side or left-end back electrode layer 12 respectively. Has been. As shown in FIG. 6, the first conductive member 50 and the second conductive member 52 are, for example,

copper ribbons

50a and 52a covered with covering

materials

In the integrated solar cell 2 of this configuration, when light is incident on the solar cells 20a to 20d from the transparent electrode layer 16 side, the light passes through the transparent electrode layer 16 and the buffer layer 14, and the photoelectric conversion layer 13 An electromotive force is generated, and for example, a current from the transparent electrode layer 16 toward the back electrode layer 12 is generated. Electric power generated in the integrated solar cell 2 can be taken out of the solar cell 2 from the first conductive member 50 and the second conductive member 52. In the present embodiment, the first conductive member 50 is a negative electrode and the second conductive member 52 is a positive electrode. However, the first conductive member 50 and the second conductive member 52 have opposite polarities. It may be appropriately changed depending on the layer configuration, connection configuration, and the like of the solar cells 20a to 20d.

Below, the manufacturing method of 2nd Embodiment is demonstrated based on FIG. 4 and FIG. 4 and 9 are partial schematic cross-sectional views showing the manufacturing process, and show a portion that becomes an opening groove between some

cells

20a and 20b.
The manufacturing method of the second embodiment is the same as the manufacturing method of the first embodiment with respect to steps a to c shown in FIG. 4, and the description of the manufacturing method of the first embodiment is incorporated. Here, the manufacturing process after d in FIG. 9 will be described.

After the steps a to c in FIG. 4, as shown in FIG. 9d, an opening groove 22 having a depth parallel to the separation groove 21 and reaching the surface position of the back electrode layer 12 is formed. At this time, the opening groove portion 22 is formed so that a part 24 of the stacked body S is left in a position spaced from both walls α and β of the opening groove portion 22 in the groove width direction of the opening groove portion 22. For example, two recesses (grooves) 22a and 22b are formed at a predetermined interval from above the stacked body S at a desired opening groove forming position by laser or mechanical scribe, so that the gap between the two

grooves

22a and 22b is formed. The opening groove part 22 in which a part of the stacked body S is left can be formed. In the present embodiment, the opening groove 22 is formed so that the second groove 22b is wider than the first groove 22a.

The back electrode layer 12 is exposed in the first and

second grooves

22 a and 22 b sandwiching the part 24 of the laminated body of the formed opening groove 22, and is partially embedded in the separation groove 21. The photoelectric conversion layer 13 is exposed. Note that an opening groove is formed at the bottom on the first groove 22a side so that the back electrode of one cell 20a is not exposed. The photoelectric conversion layer 13 embedded in the separation groove 21 may be exposed over the entire bottom portion of the first groove 22a. Further, in the present embodiment, the photoelectric conversion layer 13 is left as a part 24 of the laminate, but the buffer layer 14 and the transparent electrode layer 16 remain in this part 24. May be.

Next, as illustrated in e of FIG. 9, for example, by using an ink jet method, the insulating ink that becomes the insulating portion 44 is formed in the vicinity of the wall surface α and the first wall so that the one wall surface α of the opening groove portion 22 is covered. The droplets are ejected into the groove 22a. In this case, since the insulating ink is ejected from the stopper portion 24 toward the first groove 22a, it is prevented from being blocked by the stopper portion 24 and spreading toward the second groove 22b.
After depositing the insulating ink, the insulating portion 44 is formed by performing a thermosetting process and a photocuring process according to the ink material.

Next, as shown in FIG. 9f, the conductive layer 40 is formed on the insulating portion 44 so as to be in contact with the back electrode layer 12 of the other cell 20b from the transparent electrode layer 16 of the one cell 20a. For example, the other exposed conductive ink (conductive paste) from the transparent electrode layer 16 of one cell 20a onto the insulating portion 44 and beyond the stopper portion 24 into the second groove 22b by using the inkjet method. The droplets are ejected over a range extending to the back electrode 12 of the cell 20b. In this case, since the 2nd groove | channel 22b is wider than the 1st groove | channel 22a, it is suppressed that conductive ink spreads to the wall surface (beta) of the photovoltaic cell 20b, and does not contact the wall surface (beta) of the photovoltaic cell 20b. . Thereby, the internal leak of the photovoltaic cell 20b is prevented.

Then, heat curing treatment and photocuring treatment according to the conductive ink are performed. Thereby, the conductive layer 40 which electrically connects the transparent electrode 30 of the solar battery cell 20a and the back electrode 12 of the solar battery cell 20b is formed. The conductive layer 40 is connected to the back electrode 12 of the solar battery cell 20 b beyond the stopper portion 24.

In this embodiment, since the conductive layer 40 is formed on the insulating portion 44, the conductive layer 40 is not in contact with the wall surface α, so that the internal leakage current of the solar battery cell having the wall surface α is prevented.

As described above, an integrated solar cell 2 in which a plurality of solar cells 20a to 20d are connected as shown in FIG. 6 can be manufactured.

In the integrated solar cell 2 manufactured by the manufacturing method according to the present embodiment, the cells are connected by the opening groove 22, so that the solar cell per unit area is compared with the integrated solar cell having three separation grooves. The power generation efficiency can be improved by increasing the area of the battery cell.

Further, in the manufacturing method of the present embodiment, after the back electrode scribing step, the laminated body S having other layers constituting the solar battery cell is continuously formed, and then the opening groove portion 22 and the stopper portion 24 are formed. Thus, by separating the solar battery cells and connecting the solar battery cells, an integrated structure can be realized with a relatively small number of steps, thereby increasing the production efficiency. In addition, since the back electrode is scribed before the photoelectric conversion layer is formed, power necessary for scribing the back electrode can be suppressed, and damage to the substrate due to high output power can be prevented. Yield can be improved.

Furthermore, as shown in g of FIG. 10, an integrated solar cell including the coating insulating portion 42 may be formed by forming a coating insulating portion 42 that covers the conductive layer 40. When the film insulation part 42 is provided, the same effect as the case of 1st Embodiment can be acquired.

“Third Embodiment”
FIG. 11 is a schematic cross-sectional view showing an integrated solar cell 3 manufactured by the manufacturing method of the third embodiment of the present invention. FIG. 12 is a schematic plan view of the main part of the integrated solar cell 3 shown in FIG. 11, and FIG. 13 is a schematic plan view of the main part of Modification 3 ′ of the integrated solar cell of the present embodiment. is there.

As shown in FIG. 11 and FIG. 12, the integrated solar cell 3 includes a substrate 10 whose surface layer is an insulating layer 10a and an insulating layer 10a of the substrate 10, with a line-shaped opening groove 22 interposed therebetween. A plurality of solar cells (photoelectric conversion elements) 20a to 20d electrically connected in series in the longitudinal direction L of the tenth, a first conductive member 50 connected to the solar cell 20a at one end, And a second conductive member 52 connected to the solar battery cell 20d at the other end.

As shown in FIG. 12, the shape, size, etc. of the substrate 10 of this embodiment are appropriately determined according to the size, etc. of the integrated solar cell 3 to be applied. For example, the length of one side A rectangular shape or a rectangular shape with a length exceeding 1 m.
The solar cells 20a to 20d and the first and second

conductive members

The opening groove portion 22 is formed in parallel to the separation groove 21 and at a depth that is substantially the surface position of the back electrode layer 12. Further, in the groove width direction of the opening groove portion 22, both the walls α and β of the groove portion are stacked, that is, at positions separated from the wall surface α of one cell 20a and the wall surface β of the other cell 20b of the cells adjacent to each other across the groove portion. A part of the body, here, part of the photoelectric conversion layer 13 is left as a stopper part 24 described later. In other words, the opening groove portion 22 includes the stopper portion 24 and two concave portions (groove portions) 22a and 22b sandwiching the stopper portion 24. The width of the opening groove is, for example, 50 μm to 100 μm.

The opening groove 22 is formed at a position where the back electrode of the other cell 20b is at least partially exposed to the first groove 22a. At this time, the separation groove 21 is preferably located in the vicinity of one wall surface α of the opening groove portion 22. The separation groove 21 may be located on the one cell 20a side (under one cell 20a) from the wall surface α, but in order to suppress a loss portion that does not contribute to photoelectric conversion, the separation groove 21 is located near the wall surface α. It is hoped that

The stopper 24 is located on the back electrode 12 of the other cell 20b to which the conductive layer 40 is connected to the back electrode layer 12, and the back electrode layer 12 has one concave portion so as to contact the conductive layer 40. It must be exposed at the bottom on the 22a side.

As shown in FIG. 12, the insulating part 44 and the conductive layer 40 are formed over the entire width direction W of the substrate 10 of the solar battery cell 20a.

Note that it is only necessary that the solar cells 20 a to 20 d can be electrically connected in series, and the conductive layer 40 does not have to be formed over the entire width direction W of the substrate 10. In order to electrically connect the solar cells 20a to 20d in series, it is only necessary to connect the solar cells 20a to 20d by using the conductive layer 40 in at least a part in the width direction W. For example, as shown in FIG. For example, three conductive layers 40a may be formed in the width direction W with respect to the cell 20a.
Note that the insulating portion 44 may not be continuously formed in the width direction W as long as the conductive layer 40a is formed so as not to contact the wall surface α.

The first conductive member 50 and the second conductive member 52 are, for example, strip-shaped members that extend substantially linearly in the width direction of the substrate 10 and are connected to the right-side or left-end back electrode layer 12 respectively. Has been. As shown in FIG. 11, the first conductive member 50 and the second conductive member 52 are, for example,

copper ribbons

50a and 52a covered with

coating materials

In the integrated solar cell 3 of this configuration, when light is incident on the solar cells 20a to 20d from the transparent electrode layer 16 side, the light passes through the transparent electrode layer 16 and the buffer layer 14, and the photoelectric conversion layer 13 An electromotive force is generated, and for example, a current from the transparent electrode layer 16 toward the back electrode layer 12 is generated. The electric power generated in the integrated solar cell 3 can be taken out of the solar cell 3 from the first conductive member 50 and the second conductive member 52. In the present embodiment, the first conductive member 50 is a negative electrode and the second conductive member 52 is a positive electrode. However, the first conductive member 50 and the second conductive member 52 have opposite polarities. It may be appropriately changed depending on the layer configuration, connection configuration, and the like of the solar cells 20a to 20d.

Below, the manufacturing method of 3rd Embodiment is demonstrated based on FIG. 4 and FIG. FIG. 4 and FIG. 14 are partial schematic cross-sectional views showing the manufacturing process, and show a portion that becomes an opening groove between some

cells

20a and 20b.
The manufacturing method of the third embodiment is the same as the manufacturing method of the first embodiment with respect to steps a to c shown in FIG. 4, and the description of the manufacturing method of the first embodiment is incorporated. Here, the manufacturing process after d in FIG. 14 will be described.

After the steps from a to c in FIG. 4, as shown in d in FIG. 14, an opening groove 22 having a depth parallel to the separation groove 21 and reaching the surface position of the back electrode layer 12 is formed. At this time, the opening groove portion 22 is formed so as to leave a part 24 of the stacked body S at a position spaced from both walls α and β of the opening groove portion 22 in the groove width direction of the opening groove portion 22. For example, two recesses (grooves) 22a and 22b having a depth reaching the surface position of the back electrode layer 12 from above the stacked body S at a predetermined interval are formed by laser or mechanical scribing at a desired opening groove forming position. Thus, the opening groove portion 22 in which a part 24 of the stacked body S is left between the two

grooves

22a and 22b can be formed. In the present embodiment, the opening groove 22 is formed such that the first groove 22a is wider than the second groove 22b.

The back electrode layer 12 is exposed in the first and

second grooves

22 a and 22 b sandwiching the part 24 of the laminated body of the formed opening groove 22, and is partially embedded in the separation groove 21. The photoelectric conversion layer 13 is exposed. In the present embodiment, the photoelectric conversion layer 13 is left as a part 24 of the laminate, but the buffer layer 14 and the transparent electrode layer 16 remain in this part 24. Good.

Next, as shown in FIG. 14e, for example, using an ink jet method, the insulating ink that becomes the insulating portion 44 is deposited in the vicinity of the wall surface α so that one wall surface α of the opening groove portion 22 is covered. Then, the insulating portion 44 is formed by performing a thermosetting process and a photocuring process according to the ink material.

Next, as shown in FIG. 14 f, the conductive layer 40 is formed on the insulating portion 44 so as to be in contact with the back electrode layer 12 of the other cell 20 b from the transparent electrode layer 16 of the one cell 20 a. For example, the other cell in which the conductive ink (conductive paste) is exposed in the first groove 22a from the transparent electrode layer 16 of the one cell 20a through the insulating portion 44 by using the inkjet method. The droplets are ejected in a range extending to the back electrode layer 12 of 20b. In this case, since the conductive paste is ejected into the first groove 22a, the conductive paste is blocked by the stopper portion 24 and is prevented from spreading toward the second groove 22b. That is, it is possible to prevent the conductive ink from contacting the wall surface β of the other solar battery cell 20b. Thereby, the internal leak of the photovoltaic cell 20b is prevented.

Then, heat curing treatment and photocuring treatment according to the conductive ink are performed. Thereby, the conductive layer 40 which electrically connects the transparent electrode 30 of the solar battery cell 20a and the back electrode 12 of the solar battery cell 20b is formed. In the present embodiment, the conductive layer 40 is regulated by the stopper portion 24.

As described above, an integrated solar cell 3 to which a plurality of solar cells 20a to 20d are connected as shown in FIG. 11 can be manufactured.

In the integrated solar cell 3 manufactured by the manufacturing method of the present embodiment, the cells are connected by the opening groove 22, so that the solar cell per unit area is compared with the integrated solar cell having three separation grooves. The power generation efficiency can be improved by increasing the area of the battery cell. In particular, since the opening groove portion 22 is provided with the stopper portion 24 to suppress the spreading of the conductive ink, the width of the opening groove portion 22 can be shortened, and the power generation efficiency per unit area can be further improved. .

Further, as shown in FIG. 15g, an integrated solar cell provided with a film insulating part 42 by forming a film insulating part 42 covering the conductive layer 40 may be used. When the film insulation part 42 is provided, the same effect as the case of 1st Embodiment can be acquired.

In each of the above embodiments, the laser beam used for laser scribing is, for example, pulse-oscillated. At this time, the pulse width of the laser beam is preferably 100 ns or less, and more preferably 40 ns or less, so that the end of the removal portion does not rise. As a laser beam used for laser scribing, an Nd: YAG laser or an Nd: YVO ₄ laser excited by a laser diode having a wavelength of 1.06 μm and a pulse width of 40 ns or less can be used.
Further, the laser beam used for laser scribing includes laser harmonics (second harmonic (wavelength is about 0.53 μm), third harmonics) generated by laser diode excitation using Nd: YAG, Nd: YVO ₄ for the laser crystal. Harmonics (wavelength is about 0.355 μm) can also be used.

For mechanical scribing, a known device used for mechanical scribing can be used.

It is possible to suitably form a scribe groove having a width of 10 to 30 μm by laser scribe and a scribe groove having a width of 30 to 100 μm by mechanical scribe.

In addition, when a flexible substrate is used as the substrate 10, it can be formed by combining a roll-to-roll method and a single wafer method.

For example, the back electrode layer 12 is formed on the substrate 10, the separation groove 21 is formed, and the photoelectric conversion layer 13 is formed by a roll-to-roll method, then cut into a predetermined size, and the buffer layer 14. And formation of the transparent electrode layer 16 is implemented by a single wafer type.
In addition, for example, the process of forming the back electrode layer 12 on the substrate 10, forming the separation groove 21, and forming the photoelectric conversion layer 13 and the buffer layer 14 is performed by a roll-to-roll method. The transparent electrode layer 16 is cut and formed in a single wafer mode.
Further, for example, the back electrode layer 12 is formed on the substrate 10, the separation groove 21 is formed, the photoelectric conversion layer 13, the buffer layer 14, and the transparent electrode layer 16 are formed by a roll-to-roll method, and then have a predetermined size. Then, the above integration process is performed in a single wafer mode.

In addition, when not using a flexible substrate as the board | substrate 10, all processes are performed by a single wafer type.

Hereinafter, specific examples of the substrate and each layer suitable for each of the above-described embodiments will be described.

(substrate)
The substrate 10 is not particularly limited as long as the surface is an insulating layer, such as an insulating substrate such as glass or polyimide, or a metal substrate such as stainless steel having an insulating layer formed on the surface.
As the flexible substrate, an anodized substrate in which an anodized film (insulating film) mainly composed of Al ₂ O ₃ is formed on at least one surface side of an Al base material mainly composed of Al, Fe is mainly used. An anodic oxide film mainly composed of Al ₂ O ₃ was formed on at least one surface side of a composite base material in which an Al material composed mainly of Al was composited on at least one surface side of the Fe material as a component. Anodized substrate, Al ₂ O ₃ as a main component on at least one surface side of a base material on which an Al film whose main component is Al is formed on at least one surface side of an Fe material containing Fe as a main component An anodized substrate on which an anodized film is formed is preferable. Further, a soda lime glass (SLG) layer may be provided on the anodized film. By providing the soda lime glass layer, Na can be diffused in the photoelectric conversion layer. When the photoelectric conversion layer contains Na, the photoelectric conversion efficiency can be further improved.

(First electrode layer)
The first electrode layer (back electrode) 12 is preferably made of, for example, Mo, Cr, or W, and a combination thereof, and particularly preferably made of Mo. The back electrode layer 12 may have a single-layer structure or a laminated structure such as a two-layer structure.
Moreover, the formation method in particular of the back surface electrode layer 12 is not restrict | limited, For example, it can form by vapor phase film-forming methods, such as an electron beam vapor deposition method and a sputtering method.

The back electrode layer 12 generally has a thickness of about 800 nm, but the back electrode layer 12 preferably has a thickness of 200 nm to 1000 nm (1 μm). Thus, by making the film thickness of the back electrode layer 12 thinner than a general film, the material cost of the back electrode layer 12 can be reduced, and further, the formation speed of the back electrode layer 12 can be increased.

(Photoelectric conversion layer)
The main component of the photoelectric conversion layer 13 is not particularly limited and is preferably a compound semiconductor having at least one chalcopyrite structure because high photoelectric conversion efficiency can be obtained. The Ib group element, the IIIb group element, and the VIb group More preferably, it is at least one compound semiconductor composed of an element.

As the main component of the photoelectric conversion layer 13, at least one type Ib group element selected from the group consisting of Cu and Ag, and at least one type IIIb group element selected from the group consisting of Al, Ga, and In, It is preferably at least one compound semiconductor comprising at least one VIb group element selected from the group consisting of S, Se, and Te.

Examples of the compound _{_{semiconductor, CuAlS 2, CuGaS 2, CuInS}} 2, CuAlSe 2, CuGaSe 2, AgAlS 2, AgGaS 2, AgInS 2, AgAlSe 2, AgGaSe 2, AgInSe 2, AgAlTe 2, AgGaTe 2, AgInTe 2, Cu ( _{in, Al) Se 2, Cu} (in, Ga) (S, Se) 2, Cu in _{_{1-z in 1-x Ga}} x Se 2-y S y ( wherein, 0 ≦ x ≦ 1,0 ≦ y ≦ 2, 0 ≦ z ≦ 1) (CI (G) S), Ag (In, Ga) Se ₂ , Ag (In, Ga) (S, Se) _{2 and the} like.

_{_{_{_{Further, Cu 2 ZnSnS 4, Cu 2}}}} ZnSnSe 4, Cu 2 ZnSn (S, Se) 4, may be.
Examples of semiconductors other than the I-III-VI group semiconductors include semiconductors composed of IIIb group elements and Vb group elements such as GaAs (III-V semiconductors), IIb group elements such as CdTe, (Cd, Zn) Te, and VIb. And semiconductors composed of group elements (II-VI group semiconductors).

The film formation method of the photoelectric conversion layer 13 is not particularly limited, and can be formed by a vacuum deposition method, a sputtering method, an MOCVD method, or the like. As film formation methods for CIGS semiconductor layers, multi-source simultaneous vapor deposition, selenization, sputtering, hybrid sputtering, canochemical process, and the like are known. Examples of other CIGS film formation methods include screen printing, proximity sublimation, MOCVD, and spray (wet film formation). Any film forming method may be used.

(Buffer layer)
The buffer layer 14 is formed to protect the photoelectric conversion layer 13 when the transparent electrode layer 16 is formed and to transmit light incident on the transparent electrode layer 16 to the photoelectric conversion layer 13.
The buffer layer 14 is made of, for example, CdS, ZnS, ZnO, ZnMgO, ZnS (O, OH), or a combination thereof.
The buffer layer 14 preferably has a thickness of 10 nm to 2 μm, more preferably 15 to 200 nm. The buffer layer 26 is formed by, for example, a CBD (chemical bath deposition) method, a solution growth method, or the like.

(Insulating layer (window layer))
As described above, in the above embodiment, an insulating layer (so-called window layer) may be provided between the buffer layer 14 and the transparent conductive layer 16. This insulating layer inhibits recombination of photoexcited electrons and holes, and contributes to improvement in power generation efficiency. The composition of the insulating layer is not particularly limited, but i-ZnO, i-AlZnO (AZO), and the like are preferable. The film thickness is not particularly limited, and is preferably 10 nm to 2 μm, more preferably 15 to 200 nm. The film forming method is not particularly limited, but a sputtering method or an MOCVD method is suitable. On the other hand, when the buffer layer 14 is manufactured by the liquid phase method, it is also preferable to use the liquid phase method in order to simplify the manufacturing process.

(Second electrode layer)
The second electrode layer (transparent electrode layer) 16 may be composed of, for example, ZnO doped with Al, B, Ga, In or the like, ITO (indium tin oxide) or SnO ₂ and a combination thereof. it can. The transparent electrode layer 16 may have a single layer structure or a laminated structure such as a two-layer structure. The thickness of the transparent electrode layer 16 is not particularly limited, and is preferably 50 nm to 2 μm, more preferably 0.3 to 1 μm.
The method for forming the transparent electrode layer 16 is not particularly limited, and can be formed by a vapor deposition method such as an electron beam evaporation method or a sputtering method.
An antireflection film such as MgF ₂ may be formed on the transparent electrode layer 16.

(Insulating ink)
Examples of the insulating ink for forming the insulating

portions

42 and 44 include insulating ink IJPR (solar ink), inkjet compatible polyimide ink Rixon coat (JNC), inkjet compatible UV curable ink Rixon coat (JNC), and insulating ink DPEI. (Daicel Chemical Industries) can be used.

(Conductive ink)
Examples of the conductive ink for forming the conductive layer 40 include silver paste (NPS-J (product number, manufactured by Harima Chemicals)), transparent conductive ink (ClearOhm (registered trademark) (JNC)), silver nano ink (Daicel Chemical) Industrial), Cabot Conductive Ink CCI-300 can be used.

The above has mainly described materials and layer configurations suitable for the case where a compound semiconductor is used as a photoelectric conversion layer of a solar battery cell.
The present invention may use other than the compound semiconductor system as described above as the photoelectric conversion layer of the solar battery cell. For example, as a photoelectric conversion layer, an amorphous silicon (a-Si) thin film type photoelectric conversion layer, a tandem structure type thin film type photoelectric conversion layer (a-Si / a-SiGe tandem structure photoelectric conversion layer), a series connection structure (SCAF) A thin film photoelectric conversion layer (a-Si serial connection structure photoelectric conversion layer), a thin film silicon thin film photoelectric conversion layer, a dye-sensitized thin film photoelectric conversion layer, or an organic thin film photoelectric conversion layer may be used. . And what is necessary is just to comprise the photovoltaic cell of the layer structure according to the kind of photoelectric converting layer.

In the above embodiment, the first electrode layer provided on the substrate is made of an opaque material as the back electrode, and the second electrode formed on the photoelectric conversion layer is called a substrate type having a transparent structure. Although the solar cell having the structure has been described, the present invention can be applied to a super straight type solar cell in which the first electrode layer is a transparent electrode and the second electrode layer is an opaque electrode.
However, the manufacturing method of the present invention is highly effective in manufacturing a solar cell having a substrate type structure in which the first electrode layer is made of metal or the like and is cured by a thermal history. Is.

Claims

A method of manufacturing an integrated solar cell in which a plurality of photoelectric conversion elements are arranged and connected in series on a substrate,
Forming a first electrode layer on a substrate having at least an insulating surface;
Forming a separation groove in which the surface of the substrate is exposed at the bottom of the first electrode layer to separate the first electrode layer into a plurality of regions;
A photoelectric conversion layer and a second electrode layer are sequentially laminated so as to cover the surface of the substrate exposed to the first electrode layer and the separation groove, thereby forming a laminate.
A part of the stacked body is an opening groove part having a depth parallel to the separation groove and reaching the surface position of the first electrode layer, and spaced from both walls of the groove part in the groove width direction of the opening groove part. Forming the remaining open groove,
A connecting portion that electrically connects the second electrode layer of one of the photoelectric conversion elements adjacent to each other across the opening groove and the first electrode layer of the other element is connected to the opening groove. A method for producing an integrated solar cell, comprising forming a conductive ink by dropping from one part of the laminate to the one element side.
The method for manufacturing an integrated solar cell according to claim 1, wherein a covering insulating portion that covers the connecting portion is formed.
3. The integration according to claim 1, wherein, in the forming step of the connection portion, the part of the stacked body is used as a stopper portion that suppresses spreading of the conductive ink to the other element side. A manufacturing method of a solar cell.
Before forming the connecting portion, an insulating portion extending in the height direction of the wall surface is formed on at least a part of the wall surface on the one element side of the opening groove portion,
The method for manufacturing an integrated solar cell according to claim 1, wherein the connecting portion is formed on the insulating portion.
The method for manufacturing an integrated solar cell according to any one of claims 1 to 4, wherein the separation groove is formed by laser scribing.
The opening groove is formed by forming two grooves by mechanical scribing at a predetermined interval so that a part of the stacked body remains in a region to be the opening groove. 5. The method for producing an integrated solar cell according to any one of 5 above.
The method for manufacturing an integrated solar cell according to any one of claims 1 to 6, wherein the connection portion is formed by dropping the conductive ink by an inkjet method.