JP2000261020A - Integrated thin-film solar battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an integrated thin-film solar battery for preventing the loss of a power generating area, due to the failure of isolation and connection due to patterning, and for reducing a connection resistance loss. SOLUTION: An integrated thin-film solar battery 10 is provided with plural power generating regions constituted of a lower electrode layer 2, a photoelectric converting layer 3, and an upper electrode layer 4 on the same substrate 1 having an insulating surface. The upper electrode layer 4 is divided by mutually crossing first patterning grooves 5 and second patterning grooves 6, and the lower electrode layer 2 is divided by third patterning grooves 7 along the first patterning grooves 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of an integrated thin-film solar cell, and more particularly, to a structure in which a plurality of power generation regions including a lower electrode layer, a photoelectric conversion layer and an upper electrode layer are formed on the same substrate having an insulating surface. The present invention relates to an integrated thin-film solar cell provided with the same.

[0002]

2. Description of the Related Art In general, thin-film solar cells are roughly classified into those using a light-transmitting substrate, for example, glass, and those using a non-light-transmitting substrate, for example, a metal substrate.
From another viewpoint, a substrate having an insulating surface, for example, a substrate using glass or a metal substrate having a surface insulating layer formed thereon, and a substrate having a conductive surface, for example, a metal substrate such as stainless steel or aluminum are used. Divided into things. Of these, when the substrate has an insulating surface, a process called so-called integration may be performed in which a desired photovoltaic voltage is obtained by connecting a plurality of photovoltaic elements in series on a single substrate. Many.

[0003] Hereinafter, an integrated thin-film solar cell formed on an opaque substrate will be described in this specification, but the content described in this specification is an integrated thin-film solar cell formed on a light-transmitting substrate. The same applies to batteries. like this,
A thin-film solar cell formed on a substrate having an insulating surface,
The lower electrode layer, the photoelectric conversion layer, and the upper electrode layer are formed by laminating them in this order, and in order to integrate them, a step of patterning each layer when forming each layer is required.

The upper electrode layer on the light incident side includes:
In general, an oxide transparent conductive film is used. However, a series resistance caused by this resistance causes a power loss of the solar cell, and a fill factor (FF) in the solar cell current-voltage characteristic is reduced. Therefore, it is necessary to shorten the distance through which current flows, that is, to perform integration. The integration is performed by patterning each layer into a predetermined shape when each layer is formed.

For patterning, a mask vapor deposition method, a photo etching method, a laser scribe method, or the like is used. Among them, the laser scribe method is widely used because it is superior in cost, process, and finally the solar cell output to be obtained as compared with other methods.

An example of a method of integrating a thin-film solar cell manufactured on a substrate having an insulating surface by using a laser scribe method will be described with reference to FIGS. 9 shows a plan view (a), a sectional view (b) and a sectional view (c) of the integrated thin-film solar cell as viewed from the incident light side, and FIG. 10 is formed on the substrate 1. FIG. 11 is a perspective view of the patterning groove of each layer, and FIG. 11 is a perspective view of the patterning groove of the lower electrode layer 2 formed on the substrate 1.

First, a lower electrode layer 2 formed on a substrate 1
Is separated in a strip shape by a method such as laser scribe in a patterning groove 111 (first patterning). Next, the photoelectric conversion layer 3 represented by an amorphous semiconductor
Are stacked in a position parallel to and shifted from the first patterning groove 111 without damaging the underlying lower electrode layer 2.
Only the photoelectric conversion layer 3 is selectively removed by the patterning groove 113 (second patterning).

Further, an upper electrode layer 4 is laminated, and is parallel to the second patterning groove 113 and in the first patterning groove 1.
On the side opposite to 11, the upper electrode layer 4 alone is selectively divided and removed by the patterning groove 115 without damaging the underlying photoelectric conversion layer 3 and lower electrode layer 2 (third patterning). Thereby, the lower electrodes 2a, 2b, 2c,.
Photoelectric conversion layers 3a, 3b, 3c..., Upper electrodes 4a, 4
.. are divided into unit cells (unit power generation regions) each composed of b, 4c,..., and an integrated thin-film solar cell is formed by connecting these unit cells in series.

In the above-described first to third patterning,
In the step of dividing the upper electrode layer 4, there is a problem that the photoelectric conversion layer 3 serving as a base is easily damaged, which results in poor division and deterioration of solar cell characteristics. Therefore, in Japanese Patent Publication No. 2-264480, when the upper electrode layer 4 is removed by a laser beam, the lower electrode layer 2 as a base is removed in advance, and division failure occurs due to damage to the photoelectric conversion layer 3. (Shown as the patterning groove 112 in FIGS. 9 to 11 described above).

[0010]

In the above-described three-stage patterning process, the third patterning for selectively removing only the upper electrode layer 4 is performed by separating and separating the upper electrode layer 4 into a strip shape. If the processing is incomplete in an integration process of connecting a plurality of photovoltaic elements in series, the current of the solar cell ultimately obtained is obtained by dividing the photovoltaic elements in units of (unit power generation area). Leakage current occurs in the voltage characteristics, and the fill factor (FF) is reduced, and as a result, the output of the solar cell is reduced.

Conventionally, a laser scribe method, a mask vapor deposition method, and an etching method have been often used for the third patterning. In the laser scribing method, after forming an upper electrode layer, a laser beam is irradiated while scanning a stage on which a processing object is mounted, or a stage on which a processing object is mounted is fixed, and a laser beam is scanned while scanning. This is a method in which the upper electrode layer is thermally or molecularly evaporated by irradiation or a combination thereof to selectively remove the upper electrode layer.

However, if the underlying photoelectric conversion layer 3 or lower electrode layer 2 is damaged at this time, the adjacent cells are completely insulated and separated to the lower electrode layer 2, and a plurality of photovoltaic elements are not connected in series. , Resulting in series resistance loss. Alternatively, even in the case where the underlying photoelectric conversion layer 2 and lower electrode layer 2 are not damaged, the insulating effect between the adjacent cells becomes incomplete because the photoelectric conversion layer 3 is thermally affected to lower the resistance. This causes a leakage current, which leads to a decrease in solar cell characteristics.

When the mask evaporation method is used, it is necessary to make the substrate and the mask adhere to each other at the time of film formation, which may damage the photoelectric conversion layer and cause leakage current, and it is difficult to increase the area of the solar cell module. In addition, compared to the laser scribe method, the positioning accuracy of the mask is lower than that of laser processing, and the width of the separation groove is wider, so that the integrated thin-film solar cell does not contribute to actual power generation. ,
That is, it causes an increase in the area of the series connection portion, which causes a loss of the effective power generation area.

In the etching method, after an upper electrode layer is formed, an etching resist is patterned and printed by screen printing or the like, and the upper electrode layer is dissolved and removed with an etchant to perform patterning. In this method, the positioning accuracy in printing is lower than in the case of processing using a laser, and the width of the separation groove is larger, so that the area loss is increased and the area of the integrated thin-film solar cell is increased as in the mask evaporation method. In this case, it is difficult to perform pattern printing with stable quality.

Further, since the upper electrode layer is on the light incident side, it is necessary to use an etching resist having a high transmittance in the visible light region used in a solar cell or to remove the resist after etching. This also causes loss of incident light to the solar cell, and degrades solar cell characteristics. At the same time, in the case of industrial mass production such as handling of a resist solution using an organic solvent as a solvent and treatment of an etching solution, the production cost is increased, and there is a concern about the influence on the environment.

Further, in a mask vapor deposition method in which an upper electrode layer is patterned using a mask during film formation, and an etching method in which an etching resist is patterned and printed and then an etching treatment is performed, it is difficult to perform good processing with good reproducibility. In the case of mass production, there is a possibility that the yield will decrease and the production cost will increase.

In Japanese Patent Publication No. 2-264480, when the upper electrode layer is removed by a laser beam,
A method has been shown in which the lower electrode layer as a base is removed in advance to prevent a division failure due to damage to the photoelectric conversion layer. However, in this structure, the area of the integrated thin-film solar cell can be increased. In this case, since the photocurrent generated in the photoelectric conversion layer needs to flow through the lower electrode layer over a long distance along the integrated line, the solar cell characteristics include a large series resistance loss, and the characteristics are reduced. There is a problem of inviting.

The present invention has been made in view of the above-mentioned problems, and provides an integrated thin-film solar cell capable of preventing loss of a power generation region due to poor separation / connection due to patterning and reducing connection resistance loss. Is to do.

[0019]

According to the present invention, there is provided an integrated thin-film solar cell having a plurality of power generation regions each including a lower electrode layer, a photoelectric conversion layer, and an upper electrode layer on the same substrate having an insulating surface. The upper electrode layer is separated by a first patterning groove and a second patterning groove which intersect each other, and the lower electrode layer is separated by a third patterning groove along the first patterning groove. Integrated thin-film solar cell is provided.

That is, in the integrated type thin film solar cell of the present invention, patterning (third patterning) for insulatingly dividing the upper electrode layer into strips for each unit power generation region (cell).
In the above, after forming the lower electrode layer and before laminating the photoelectric conversion layer, the lower electrode layer corresponding to the position immediately below the upper electrode layer is removed by patterning in advance, so that the upper electrode layer is When separating and forming,
Simultaneous patterning failure of each layer below the upper electrode layer, that is, failure of separation of the lower electrode layer and damage of the photoelectric conversion layer or the lower electrode layer is prevented, and the first patterning groove and the first Separation by the two patterning grooves makes it possible to easily perform patterning for further connecting the power generation regions connected in series in parallel only by patterning with a laser beam.

Further, if the lower electrode layer is configured to be separated by the fourth patterning groove along the second patterning groove, the lower electrode layer, the photoelectric conversion layer, and the upper Laser light can be used in forming both the patterning groove for connecting the power generation regions composed of the electrode layers in series and the patterning groove for connecting the power generation regions connected in series in parallel. Patterning with higher accuracy can be performed. Therefore, an integrated thin-film solar cell with high efficiency and high yield can be obtained.

The third patterning groove is composed of a group of island-like grooves formed intermittently in the longitudinal direction, and each island-like groove has a width of the upper electrode layer separated and formed by the second patterning groove. In this case, a current path is formed by the lower electrode layer between the adjacent island-shaped grooves, and the power generation regions connected in series can be further connected in parallel. Thereby, it is possible to reduce the resistance of the power generation regions connected in series, which is a problem when increasing the area of the integrated thin-film solar cell.

The first patterning groove has a smaller width than the third patterning groove, and the first patterning groove and the third patterning groove have a smaller width.
When the patterning grooves are projected, one end in the longitudinal direction is aligned and / or the second patterning groove has a narrower width than the fourth patterning groove, and the second patterning groove and the second patterning groove have the same width. When the patterning grooves of No. 4 are projected, since one end in the longitudinal direction is aligned, separation failure due to lowering of the resistance of the photoelectric conversion layer due to irradiation of laser light or the like can be prevented.

The third patterning groove is composed of a group of island-shaped grooves formed intermittently in the longitudinal direction, and when the second patterning groove and the third patterning groove are projected, the second patterning groove becomes By passing between adjacent island-shaped grooves of the third patterning groove, it is possible to easily perform processing for connecting adjacent power generation regions in series with each other.
When the second patterning groove has an interval of 150 mm or less, the series resistance loss of the integrated thin-film solar cell having the structure of the present invention can be suppressed to a level that causes no practical problem.

If the first or third patterning groove is
By having an interval of not more than mm, the loss due to the resistance of the upper electrode or the lower electrode can be suppressed to a level that causes no practical problem. Therefore, it is possible to provide an integrated thin-film solar cell capable of preventing loss of the power generation region due to poor separation / connection due to patterning and capable of reducing connection resistance loss. Such an integrated thin-film solar cell is configured by highly accurate patterning using laser light. That is, it is possible to overcome problems such as low positioning accuracy of a mask or the like in the mask vapor deposition method or the etching method, a large separation groove width, and a decrease in optical characteristics due to an etching resist solution.

In the present invention, the substrate may be an opaque substrate such as a metal substrate, or a translucent substrate made of resin or glass. When a light-transmitting substrate is used, the lower electrode layer is on the light incident side, and the lower electrode layer, the photoelectric conversion layer, and the upper electrode layer are stacked on the light-transmitting substrate,
As the lower electrode layer, an oxide transparent conductor film or a laminated film thereof can be used, and as the upper electrode layer, a reflective metal electrode film or a laminated film of them and an oxide transparent conductor film can be used. The material of the substrate is stainless steel as an opaque substrate,
As a light-transmitting substrate, a film such as a vinyl chloride resin, a polyester resin, a polyimide resin, a fluororesin, an acrylic resin, or glass may be used. As the material of the lower electrode layer, Ag, Al, Ti,
Cr, Mo, W, Ni, ZnO, etc. can be used,
The lower electrode layer can be formed by a sputtering method or an evaporation method.

The photoelectric conversion layer is a power generation region configured to convert irradiated light into electricity and extract the light from the pair of lower electrode layer and upper electrode layer, and is formed of an amorphous semiconductor layer or a microcrystalline semiconductor layer. By doing so, it is possible to provide a flexible solar cell which can have a relatively large area and a relatively low cost. Specifically, these semiconductor layers include Si, SiC and the like. As a material for the photoelectric conversion layer, amorphous silicon, microcrystalline silicon, or polycrystalline silicon can be given. For example, a film can be formed by a plasma CVD apparatus. Among them, amorphous silicon or microcrystalline silicon is preferable because it has a small effect on the environment, can provide a relatively low cost, and can provide a flexible solar cell. As a material for the upper electrode layer, a material having transparency such as ITO can be used, and a film can be formed by a sputtering method or the like.

[0028]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of an integrated thin-film solar cell according to the present invention and an example of its production will be described below with reference to examples. Example 1 FIG. 1 shows a plan view (a), a sectional view taken along the same line (b) and a sectional view taken along the same line (c) of an integrated thin-film solar cell viewed from an incident light side, and FIG. FIG. 3 is a perspective view of a patterning groove of each layer formed on the substrate 1. FIG. 3 is a cross-sectional view (a to f) of a manufacturing process of an integrated thin-film solar cell formed on the substrate 1.
Will be described. FIG. 4 is a perspective view of a patterning groove formed in the lower electrode layer 2.

As shown in FIGS. 1 and 2, the integrated thin-film solar cell 10 has a plurality of power generation regions including a lower electrode layer 2, a photoelectric conversion layer 3 and an upper electrode layer 4 on the same substrate 1 having an insulating surface. It is provided as a unit cell. In this example, the substrate 1 is an opaque substrate, specifically, a stainless steel substrate 1 coated with a polymer resin containing polyimide as a main component, and has a configuration in which light is incident from the upper electrode layer 4 side.

The upper electrode layer 4 is formed by depositing ITO by a sputtering method or the like, and is formed by a plurality of first patterning grooves 5 and second patterning grooves 6 which cross each other. 4a, 4b, 4
c ... are separated. These patterning grooves 5
And 6 are parallel grooves having the side surfaces of the respective grooves facing each other, and penetrate through the upper electrode layer 4 to reach the photoelectric conversion layer 3. The groove width of the first patterning groove 5 is about 50 μm, and the groove width of the second patterning groove 6 is about 5 mm. The first patterning groove 5 further reaches the lower electrode layer 2 through the photoelectric conversion layer 3. The photoelectric conversion layer 3 is formed by laminating an amorphous semiconductor thin film or a microcrystalline semiconductor thin film by plasma CVD or the like.

The lower electrode layer 2 is formed by successively laminating Ag and ZnO, and is separated into rectangular lower electrodes 2a, 2b, 2c,... Lower electrode 2 located below first patterning groove 5
a, 2b, 2c,... are removed by the third patterning groove 7 along the first patterning groove 5. In this embodiment, the third patterning groove 7 includes a group of intermittently formed island-shaped grooves 13.
Are formed corresponding to the intervals between the upper electrodes 4a, 4b, 4c,... Formed separately by the second patterning groove 6. The patterning groove 11 and the island-shaped groove 13 are parallel grooves having the side surfaces of the grooves 11 and 13 facing each other, and the respective grooves penetrate the lower electrode layer 2 to reach the substrate 1. The groove width of the patterning groove 11 is about 50 μm, and the groove width of the island-shaped groove 13 is about 200 μm.

The first patterning groove 5 of the upper electrode layer 4 has a width smaller than that of the island-shaped groove 13. When the first patterning groove 5 and the island-shaped groove 13 are projected, one of them in the longitudinal direction is projected. The edges are aligned. In this example, the projection of the first patterning groove 5 is located inside the island groove 13 by a predetermined distance (here, about 75 μm in the width direction and about 75 μm in the length direction) from the groove side surface 13 a of the island groove 13. . Further, the second patterning groove 6 and the island-shaped groove 1 of the upper electrode layer 4 described above are formed.
When the third patterning groove 6 is projected, the second patterning groove 6 is
Pass through. The interval between the second patterning grooves is 10
0 mm.

Hereinafter, a method for manufacturing an integrated thin-film solar cell according to an embodiment of the present invention will be specifically described. First, Ag and ZnO are continuously laminated as a lower electrode layer 2 on one surface of a stainless steel substrate 1 coated with a polymer resin containing polyimide as a main component by a sputtering method (FIG. 3A). At this time, the film forming means is not limited to the sputtering method, but may be, for example, an evaporation method.

A patterning groove 11 is formed by using a laser scribe method, is divided into strip-shaped unit cells by insulation (first patterning), and corresponds to a portion of the upper electrode layer 4 immediately below the first patterning groove 5. The lower electrode layer 2 is patterned and removed in an island shape as shown by the island-shaped groove 13 (FIGS. 3B and 4). In the present embodiment, the patterning groove 1 of the lower electrode layer 2 is irradiated with a laser beam 21.
1 is formed with a width of 50 μm, and the island-shaped groove 13 is formed with a width of 200 μm. As the laser light 21, the second harmonic (SHG, wavelength λ =) of a continuous wave Nd: YAG laser using a Q switch drive is used. 532 nm).

Subsequently, an amorphous semiconductor thin film, a microcrystalline semiconductor thin film, or the like is laminated as a photoelectric conversion layer 3 by means such as plasma CVD (FIG. 3C), and further, at a position parallel to and close to the first patterning groove 5. Then, the photoelectric conversion layer 3 is selectively removed by irradiating a laser beam 22 from above the photoelectric conversion layer 3 to form a processing groove 15 for electrically connecting the upper electrode layer 4 and the lower electrode layer 2 (FIG. 3D). , Second patterning).

Further, ITO is formed as the upper electrode layer 4 by a sputtering method or the like (FIG. 3E). At this time,
By using a metal mask, a second patterning groove 6 which intersects a first patterning groove 5 described later at a substantially right angle is formed (FIGS. 1a, 1c and 2). In the present embodiment, the width of the second patterning groove 6 is set to 5 because it is necessary to allow a sufficient margin for the alignment accuracy of the metal mask.
mm, and the distance between adjacent second patterning grooves 6 was 100 mm.

Subsequently, the laser beam 2 is applied from above the upper electrode layer 4 toward the island-shaped groove 13 in which the photoelectric conversion layer 3 is formed.
4 to form a first patterning groove 5 having a width of 50 μm and a length of 97 mm (FIGS. 3f and 1b, third patterning). The first patterning groove 5 insulates the upper electrode layer 4 in the longitudinal direction to form upper electrodes 4a, 4b, 4c,... And removes the photoelectric conversion layer 3 in the vertical direction.
Thereby, when the first patterning groove 5 has a width smaller than that of the third patterning groove 7, that is, the island-shaped groove 13, and when the first patterning groove 5 and the island-shaped groove 13 are projected, one of these in the longitudinal direction is projected. The edges can be aligned.

It is preferable that the width of the second patterning groove 6 is smaller because the larger the width of the second patterning groove 6 is, the more the power generation effective area is lost. For example, the width of the second patterning groove 6 is about 5 to 10 mm as in this embodiment. In this case, the effect of reducing the series resistance loss in the present invention is larger than the loss of the effective power generation area. Based on this example, the output characteristics of the integrated thin-film solar cell when the effective power generation size was 240 mm × 240 mm was AM1.5 (1
(00 mW / cm ² ), the fill factor was 0.67, and the maximum output was 5.6 W.

As described above, in the integrated thin-film solar cell 10 of the present invention, in the patterning (third patterning) for insulatingly dividing the upper electrode layer 4 into strips for each unit cell, the lower electrode layer 2 After the film formation, before laminating the photoelectric conversion layer 3, the lower electrode layer 4 corresponding to a position immediately below the upper electrode layer 4 to be patterned is previously removed by patterning, so that, for example, the lower electrode layer 4 has an island shape. By forming the groove 13, when the upper electrode layer 4 is separated and formed by the laser beam 24 in the first patterning groove 5, the separation failure in the lower electrode layer 2 from the upper electrode layer 2 and the photoelectric conversion layer are performed simultaneously. 3 or the lower electrode layer 2 is prevented from being damaged, and the upper electrode layer 4 is connected in series by being separated by a first patterning groove 5 and a second patterning groove 6 which cross each other. Patterning to connect the power generation region further in parallel can be easily performed only by patterning by laser light.

The third patterning groove 7 is formed of a group of island-shaped grooves 13 formed intermittently in the longitudinal direction, and each of the island-shaped grooves 13 is formed separately by the second patterning groove 6. Since it has a length corresponding to the width of the layer 4, a current path is formed by the lower electrode layer 2 between the adjacent island-shaped grooves 13, and the power generation regions connected in series can be further connected in parallel. The resistance of the power generation region connected in series can be reduced.

Further, when the first patterning groove 5 has a width smaller than that of the third patterning groove 7, that is, the island-shaped groove 13, and the first patterning groove 5 and the island-shaped groove 13 are projected, when the first patterning groove 5 and the island-shaped groove 13 are projected, Since one end is aligned, it is possible to prevent separation failure due to low resistance or the like of the photoelectric conversion layer 3 due to laser light irradiation. Further, the third patterning groove 7
Comprises a group of island-shaped grooves 13 formed intermittently in the longitudinal direction, and the second patterning groove 6 and the third patterning groove 13
Is projected, the second patterning groove 6 passes between the adjacent island-shaped grooves 13 of the third patterning groove 7, so that the processing of connecting the adjacent power generation regions in series can be easily performed. it can.

Embodiment 2 Another embodiment of the integrated thin-film solar cell according to the present invention will be described from the manufacturing process with reference to FIGS. In this embodiment, in addition to the configuration of the first embodiment, the lower electrode layer is further removed by the fourth patterning groove along the second patterning groove, and the portion of the lower electrode layer located below the second patterning groove is removed. 1 shows an example of an integrated thin-film solar cell.

FIG. 5 shows a plan view (a), a sectional view taken along the same line (b) and a sectional view taken along the same line (c) of the integrated thin-film solar cell as viewed from the incident light side, and FIG. FIG. 7 shows a perspective view of a patterning groove of each layer formed in FIG.
Each cross-sectional view (a to f) of the manufacturing process of the integrated thin-film solar cell formed above will be described. FIG. 8 is a perspective view of a patterning groove formed in the lower electrode layer 2.

In the manufacture of the integrated thin-film solar cell 20,
First, as an opaque substrate having an insulating surface, an aluminum substrate 1 whose surface is coated with alumite by anodic oxidation is used.
g, Al and ZnO are successively laminated by a vapor deposition method (FIG. 7A). Next, a patterning groove 2 for connecting adjacent power generation regions to each other by using a laser scribe method.
1 is formed, and is divided into strip-shaped unit cells by insulation (first patterning), and a third patterning groove 27 is formed in the lower electrode layer 2 directly below the first patterning groove 25 of the upper electrode layer 4 described later. I do. The third patterning groove 27 is formed by patterning and removing the lower electrode layer 2 into an island shape as shown by the island-shaped groove 13 as in the first embodiment (FIGS. 7B and 8).

Subsequently, the patterning groove 2 of the lower electrode layer 2
The fourth patterning groove 28 extends in a direction substantially perpendicular to
Are formed by a laser scribe method (FIGS. 5A and 5A).
c). In this embodiment, processing is performed simultaneously with the step of forming the patterning groove 21 of the lower electrode layer 2.
For example, continuous oscillation Nd: Y using a Q switch drive
Third harmonic of an AG laser (THG, wavelength λ = 355n)
m) with a repetition frequency of 5 kHz and a processing surface power of 5 kW / cm
^2. Processing speed 500mm / s, processing surface beam size 50
Irradiation was performed at μm × 50 μm, and scanning of one groove was performed a plurality of times, thereby setting the groove width to 200 μm.

Subsequently, the photoelectric conversion layer 3 and the upper electrode layer 4 are successively formed (FIGS. 7C and 7D), and then the laser beam 33 is applied from above the upper electrode layer 4 at a position parallel to and close to the patterning groove 21. And the upper electrode layer 4 and the lower electrode layer 2 are electrically connected by the patterning groove 22 (second patterning). Further, the inside of the island-shaped groove 13 of the lower electrode layer 2, which has been removed in an island shape in advance, is irradiated with laser light 34 from above the upper electrode layer 4 to divide the upper electrode layer 4 into a plurality of upper electrodes 4a, 4a.
The first patterning 25 for insulating and separating into b, 4c,.
Is formed (FIG. 7E). As in the first embodiment, the projection surface of the first patterning groove 25 has a groove side surface 13 a of the island-shaped groove 13.
Is located inside the island-shaped groove 13 which is separated from the groove by a predetermined distance, and does not contact the groove side surface 13a.

At this time, a second patterning groove 26 in a direction substantially perpendicular to the first patterning 25 is simultaneously formed on the upper electrode layer 4 (FIGS. 5A and 5C). The second patterning groove 26 is such that the laser beam is projected inside the fourth patterning groove at a predetermined distance from the groove side surface of the fourth patterning groove 28 formed by removing the lower electrode layer 2 in advance. Formed by irradiation. Therefore, the second patterning groove 26 becomes the third patterning groove 27,
That is, when the first patterning groove 25 and the island-shaped groove 13 have a width smaller than that of the island-shaped groove 13 and are projected, their one ends in the longitudinal direction are aligned. The groove width of the second patterning groove 26 was 50 μm. Also, the second patterning groove 26
Was 100 mm.

In this embodiment, the order of the second patterning and the third patterning is not limited to this, and the insulating separation process (third patterning) of the upper electrode layer 4 is performed on the contrary.
May be performed, and then electrical connection processing (second patterning) between the upper electrode layer 4 and the lower electrode layer 2 may be performed. Further, by providing two types of optical paths in a single device,
The second patterning and the third patterning may be performed simultaneously using laser light. In addition, based on this example, the output characteristic of the integrated thin-film solar cell when the effective power generation size is 240 mm × 240 mm is AM1.5 (100
mW / cm ² ), the fill factor was 0.67 and the maximum output was 5.7 W.

According to this embodiment, the lower electrode layer 2
However, since the portion of the lower electrode layer 2 located below the second patterning groove 26 is removed by the fourth patterning groove 28 along the second patterning groove 26, the lower electrode layer 2, the photoelectric conversion layer 3, and the upper electrode Laser light can be used to form both a patterning groove for connecting the power generation regions composed of the layer 4 in series and a patterning groove for connecting the power generation regions connected in series in parallel. Patterning with higher accuracy can be performed. Therefore, an integrated thin-film solar cell with high efficiency and high yield can be obtained.
Further, when the second patterning groove 26 has a smaller width than the third patterning groove 27, that is, the island-shaped groove 13, and the first patterning groove 25 and the island-shaped groove 13 are projected, one end in the longitudinal direction is formed. Are aligned, it is possible to prevent separation failure due to a reduction in the resistance of the photoelectric conversion layer 3 due to irradiation with laser light.

[0050]

According to the integrated thin film solar cell of the present invention,
In patterning (third patterning) for insulatingly dividing the upper electrode layer into strips for each unit power generation region (cell), after forming the lower electrode layer and before laminating the photoelectric conversion layer,
By removing the lower electrode layer immediately below the position where the upper electrode layer is patterned by patterning in advance, when the upper electrode layer is separated and formed by laser light, patterning of each layer below the upper electrode layer is performed simultaneously. The defect, that is, the separation failure of the lower electrode layer and the damage of the photoelectric conversion layer or the lower electrode layer are prevented, and the upper electrode layer is separated in series by the first patterning groove and the second patterning groove crossing each other. Patterning for further connecting the connected power generation regions in parallel can be easily performed only by patterning with a laser beam. Therefore, it is possible to provide an integrated thin-film solar cell capable of preventing loss of the power generation region due to poor separation / connection due to patterning and capable of reducing connection resistance loss.

[Brief description of the drawings]

FIG. 1 is a perspective view schematically showing a patterning structure of each layer in a plan view, a longitudinal sectional view, and a transverse sectional view showing a patterning structure of an integrated thin film solar cell according to an embodiment of the present invention.

FIG. 2 is an enlarged perspective view, partly in section, of a patterning groove of each layer formed on the substrate of FIG. 1;

FIG. 3 is a cross-sectional view illustrating a manufacturing process of each layer formed on the substrate 1 of FIG. 1;

FIG. 4 is an enlarged partial cross-sectional perspective view illustrating a patterning groove in a lower electrode layer formed on a substrate 1 of FIG. 1;

FIG. 5 is a perspective view schematically showing a patterning structure of each layer in a plan view, a longitudinal sectional view, and a transverse sectional view showing a patterning structure of an integrated thin film solar cell according to another embodiment of the present invention.

6 is an enlarged perspective view, partly in section, of a patterning groove of each layer formed on the substrate of FIG. 5;

FIG. 7 is a cross-sectional view illustrating a manufacturing process of each layer formed on the substrate 1 of FIG. 5;

FIG. 8 is a partially enlarged perspective view illustrating a patterning groove in a lower electrode layer formed on the substrate 1 of FIG.

FIG. 9 is a plan view, a longitudinal sectional view, and a perspective view schematically showing a patterning structure of each layer in a longitudinal sectional view and a transverse sectional view showing a patterning structure of a conventional integrated thin film solar cell.

10 is an enlarged perspective view of a partial cross section of a patterning groove of each layer formed on the substrate of FIG. 9;

FIG. 11 is a partially enlarged perspective view illustrating a patterning groove in a lower electrode layer formed on the substrate 1 of FIG. 9;

[Explanation of symbols]

1 Substrate 2 Lower electrode layers 2a, 2b, 2c, ... Lower electrodes 2'a, 2'b, 2'c, ... divided for each unit element, for electrically connecting the upper electrode layer and the lower electrode layer Lower electrode portion 3 Photoelectric conversion layer 3a, 3b, 3c,... Photoelectric conversion layer divided for each unit element 4 Upper electrode layer 4a, 4b, 4c,... Upper electrode divided for each unit element 5 First patterning groove 6 Second patterning groove 7 Third patterning groove 10 Integrated thin film solar cell 13 Island-shaped groove (third patterning groove) 20 Integrated thin film solar cell 27 Fourth patterning groove

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Taniguchi 22-22 Nagaikecho, Abeno-ku, Osaka City, Osaka F-term (reference) 5F051 BA12 CB21 EA02 EA09 EA10 EA11 EA16 GA03

Claims (7)

[Claims] 1. An integrated thin-film solar cell having a plurality of power generation regions each including a lower electrode layer, a photoelectric conversion layer, and an upper electrode layer on the same substrate having an insulating surface, wherein the upper electrode layer has Wherein the lower electrode layer is separated by a third patterning groove along the first patterning groove, and the lower electrode layer is separated by a third patterning groove along the first patterning groove. 2. The integrated thin-film solar cell according to claim 1, wherein the lower electrode layer is further separated by a fourth patterning groove along the second patterning groove. 3. An upper electrode layer in which a third patterning groove is composed of a group of island-shaped grooves formed intermittently in a longitudinal direction, and each island-shaped groove is formed separately by the second patterning groove. 3. The integrated thin-film solar cell according to claim 1, having a length corresponding to the width of the integrated thin-film solar cell. 4. The first patterning groove has a width smaller than that of the third patterning groove, and when the first patterning groove and the third patterning groove are projected, one ends thereof in the longitudinal direction are aligned. And / or the second patterning groove has a narrower width than the fourth patterning groove, and when projecting the second patterning groove and the fourth patterning groove, one end thereof in the longitudinal direction is The integrated thin-film solar cell according to any one of claims 1 to 3, which is arranged. 5. The third patterning groove comprises a group of island-shaped grooves formed intermittently in the longitudinal direction. When the second patterning groove and the third patterning groove are projected, a second patterning groove is formed.
The integrated thin-film solar cell according to any one of claims 1 to 4, wherein the patterning groove passes between adjacent island-shaped grooves of the third patterning groove. 6. The integrated thin-film solar cell according to claim 1, wherein the second patterning grooves have an interval of 150 mm or less. 7. The method according to claim 1, wherein the first or third patterning groove is
The integrated thin-film solar cell according to any one of claims 1 to 6, having an interval of 5 mm or less.