JP2001210851A - Integrated thin-film solar cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To isolate an upper electrode layer at a high speed and in high yield. SOLUTION: When a splitting groove 14 is formed in a lower electrode layer 12 by the laser scribe method and a substrate is insulated and split, a square groove 15 is formed just beneath a position where an upper electrode layer 19 is insulated and split and a square insulating and isolating area insulated electrically from its periphery is formed. Then, the upper electrode layer 19, a photoelectric conversion layer 16, and the lower electrode layer 12 are simulteneously removed in the intermediate part in the widthwise direction of the insulating and isolating area, by using a laser light, thus forming a splitting groove 21 for insulating and isolating the upper electrode layer 19. Thus, the splitting groove 21 is formed in the insulating and isolating area, thereby giving no damage to such a part that functions as a power generating area in the photoelectric conversion layer 16. Therefore, it is unnecessary to carefully control a laser light not to damage the photoelectric conversion layer 16 or lower electrode layer 12 as in the conventional manner, and the substrate can be treated at a high speed and in high yield.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an integrated thin-film solar cell having a plurality of power generation regions connected in series on the same substrate.

[0002]

2. Description of the Related Art In general, thin-film solar cells are roughly classified into those using a light-transmitting substrate such as glass and those using a non-light-transmitting substrate such as a metal substrate. From another viewpoint, a metal substrate having a surface insulating layer or a substrate having an insulating surface such as glass, or a substrate having a conductive surface such as a metal substrate such as stainless steel or aluminum is used. And divided into When the substrate has an insulating surface, a so-called integration process for obtaining a desired photovoltaic power by connecting a plurality of photovoltaic elements in series on a single substrate is often performed. .

A thin film solar cell formed on a substrate having the above-mentioned insulating surface is formed by sequentially laminating a lower electrode layer, a photoelectric conversion layer, and an upper electrode layer. At the time of forming each layer, a step of patterning each layer is required.

A transparent conductive oxide film is generally used as an upper electrode layer on the light incident side. However,
The power loss of the solar cell is caused by the series resistance caused by the resistance of the oxide transparent conductive film, and the fill factor (FF) in the solar cell current-voltage characteristic is reduced. Therefore,
In order to suppress the series resistance loss as described above, it is necessary to shorten (ie, integrate) a current flowing distance in a unit cell.

In the patterning process for integration, a mask vapor deposition method, a photo etching method, a laser scribe method, or the like is used. Also, the laser scribe method is mainly developed because the laser scribe method is superior to other methods.

Conventionally, as a method of manufacturing a thin film solar cell integrated on a substrate having an insulating surface by using the laser scribe method, there is a method as shown in FIGS. In this method, first, FIGS. 9A and 9B
As shown in FIG. 1, a lower electrode layer 2 is formed on a substrate 1. Then, as shown in FIG. 9 (c), the lower electrode layer 2 is insulated and separated into strips at the first patterning line 4 by a laser scribe method of irradiating the lower electrode layer 2 with laser light 3.

Next, as shown in FIG. 9D, a photoelectric conversion layer 5 typified by an amorphous semiconductor is laminated. After that, as shown in FIG. 9E, the position of the second patterning line 6 parallel to the first patterning line 4 is irradiated with laser light 7 without damaging the underlying lower electrode layer 2. Only the photoelectric conversion layer 5 is selectively removed.

Next, as shown in FIG. 9F, the upper electrode layer 8
Are laminated. Then, as shown in FIG. 9 (g), the third patterning line 9 which is parallel to the second patterning line 6 and located on the opposite side of the second patterning line 6 from the first patterning line 4 is formed. The position is irradiated with laser light 10 to selectively separate only the upper electrode layer 8 without damaging the underlying photoelectric conversion layer 5 and lower electrode layer 2. Thus, an integrated thin-film solar cell having the sectional structure as shown in FIG. 7 and the lower electrode layer 2 having a planar shape as shown in FIG. 8 is formed.

However, in the case of the above-described method, the underlying photoelectric conversion layer 5 is liable to be damaged during the step of dividing the upper electrode layer 8, thereby causing poor division and deteriorating solar cell characteristics. There is a problem.

In order to solve the above-mentioned problem, Japanese Unexamined Patent Publication No. 2-264480 discloses an upper electrode layer 8.
Is removed by laser light at the position of the third patterning line 9 at a position corresponding to the third patterning line 9 in the underlying lower electrode layer 2 while leaving only both ends. . By doing so, there is no damage to the photoelectric conversion layer 5 when dividing the upper electrode layer 8 at the position of the third patterning line 9 later, and no division failure occurs due to damage to the photoelectric conversion layer 5. .

[0011]

However, a method for manufacturing an integrated thin-film solar cell using the conventional laser scribe method shown in FIG. 9 and a method disclosed in Japanese Patent Application Laid-Open No. 2-26448.
No. 0 discloses a method of manufacturing an integrated solar cell,
There are the following problems.

First, in the method of manufacturing the integrated thin-film solar cell shown in FIG. 9, the third step of selectively removing only the upper electrode layer 8 in the three-step patterning process described above.
The patterning is performed to insulate and separate the upper electrode layer 8 into a strip shape and divide the unit into unit cells. Therefore, if the third patterning process is incomplete in the integration step of forming a plurality of photovoltaic elements in series, the fill factor (F) is determined by the leakage current generated inside the power generation region of the finally obtained solar cell. .F.) Decreases, resulting in a decrease in solar cell output.

Conventionally, in this third patterning, FIG.
In addition to the use of the laser scribe method, a mask vapor deposition method and an etching method are often used.

In the laser scribing method, after the upper electrode layer 8 is formed, the upper electrode layer 8 is thermally or molecularly irradiated by irradiating a laser beam 10 while scanning a stage on which a workpiece is mounted. And selectively removed.
In this case, the laser light 10 may be scanned while the stage on which the object to be processed is mounted is fixed, or both may be used in combination.

However, in this case, if the underlying photoelectric conversion layer 5 and the lower electrode layer 2 are damaged, adjacent cells are completely insulated and separated to the lower electrode layer 2, and a plurality of photovoltaic elements are connected in series. Not connected. Alternatively, a series resistance loss may occur. Furthermore, even if the underlying photoelectric conversion layer 5 and the lower electrode layer 2 are not damaged, the photoelectric conversion layer 5 is thermally affected by the laser beam 10 to lower the resistance, thereby reducing the distance between adjacent cells. May be incompletely separated, and a leakage current may be caused to deteriorate the solar cell characteristics.

On the other hand, in the above-mentioned mask vapor deposition method, it is necessary to bring the substrate and the mask into close contact with each other at the time of film formation. There is a problem that there is. Further, the positioning accuracy of the mask is lower than that of the laser processing by the laser scribe method, and the width of the separation groove is increased. For this reason, it causes an increase in the area of the serially connected portion that does not contribute to actual power generation (that is, causes loss of the power generation effective area).

In the etching method, after forming the upper electrode layer, an etching resist is patterned and printed by screen printing or the like, and the upper electrode layer is dissolved and removed with an etching solution to perform patterning. In this method, the positioning accuracy in the printing is lower than that in the case of laser processing, and the width of the separation groove is increased. Therefore, as in the case of the mask evaporation method,
When the area of the loss is increased and the area of the integrated thin-film solar cell is increased, there is a problem that patterning printing with stable quality is difficult. 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 a visible light region as used in a solar cell, or to remove the resist after etching. However, in any case, loss of incident light to the solar cell is caused, and the characteristics of the solar cell are degraded. At the same time, it is generally necessary to handle a resist solution using an organic solvent as a solvent, treat an etching solution, and the like. In the case of mass production on an industrial scale, the production cost increases, and there is a concern about the effect on the environment. There is also a problem.

In any case, the upper electrode layer 8 is irradiated with a laser beam 10 from above to selectively remove the upper electrode layer 8, or the upper electrode layer is patterned using a mask during film formation. It is difficult to perform good processing with good reproducibility in the mask vapor deposition method performed and the etching method of etching the upper electrode layer after patterning and printing the etching resist. This can lead to a decrease and an increase in production costs.

Further, in the method of manufacturing an integrated solar cell disclosed in Japanese Patent Application Laid-Open No. 2-264480, prior to removing the upper electrode layer 8 with the laser beam 10, A position corresponding to the patterning line 9 is removed except for both ends. In that case, the lower electrode layer 2
When the laser scribing method is used as a method for removing the laser beam, a large number of scans are required when wide processing is performed by a laser beam, so that there is a problem that the manufacturing tact is greatly reduced. In addition, when the mask vapor deposition method is used, there is a problem that the area of the non-power-generating portion is increased due to low positioning accuracy and the like.

An object of the present invention is to provide an integrated thin-film solar cell capable of performing high-yield high-speed separation of an upper electrode layer.

[0021]

In order to achieve the above-mentioned object, the present invention provides a method for forming a lower electrode layer, a photoelectric conversion layer and an upper electrode layer which are sequentially laminated on a substrate having an insulating surface. In the integrated thin-film solar cell, in which a plurality of power generation regions are connected in series on the substrate, the lower electrode layer immediately below a patterning line that electrically separates the upper electrode layer between power generation regions adjacent to each other. It is characterized in that an insulating isolation region electrically isolated from the surrounding lower electrode layer is provided in the portion.

According to the above configuration, the lower electrode layer immediately below the patterning line for electrically separating the upper electrode layer is provided with the insulating isolation region electrically insulated from the periphery. Therefore, damage to the photoelectric conversion layer when insulating and separating the upper electrode layer along the patterning line in the upper electrode layer will occur in the upper region of the insulating separation region, and the portion functioning as the power generation region Will not occur. As a result, it is not necessary to carefully operate the laser beam so as not to damage the photoelectric conversion layer and the lower electrode layer as in the related art. That is, high-speed processing can be performed with a high yield.

Further, the integrated thin-film solar cell of the present invention
Along the patterning line for separating the upper electrode layer,
It is desirable to provide a separation groove penetrating the upper electrode layer, the photoelectric conversion layer, and the lower electrode layer.

According to the above configuration, when the upper electrode layer is insulated and separated, the upper electrode layer, the photoelectric conversion layer, and the lower electrode layer may be collectively removed in a groove shape. Therefore, an integrated thin-film solar cell having excellent reproducibility and excellent characteristics can be obtained as compared with the case where only the upper electrode layer is insulated and separated as in the conventional case.

Further, the integrated thin film solar cell of the present invention
It is desirable that the separation groove be provided so as to pass through the insulating separation region of the lower electrode layer.

According to the above configuration, when the separation groove is formed by laser light, thermal effects on the peripheral edge of the processing groove due to the irradiation of the laser light and the like are caused in the insulating separation region and the upper part of the insulating separation region. Limited within the area. As a result, separation failure due to the above-described thermal influence is prevented, and characteristics and yield are improved.

Further, the integrated thin-film solar cell of the present invention
It is desirable that the insulating separation region of the lower electrode layer be a region surrounded by a closed loop-shaped insulating line.

According to the above configuration, when forming the insulating isolation region with laser light, it is only necessary to draw a closed curve by making one round of the laser light. Therefore, the insulating isolation region having a certain width can be easily formed as compared with a case where the lower electrode layer is removed by scanning the laser light a plurality of times. In this way, the number of times of scanning with laser light is drastically reduced as a whole, and the processing time is greatly reduced. Here, the “closed loop-shaped insulated wire” is a concept of a line having insulation properties arranged in a closed loop to electrically insulate the inside and outside of the closed loop.

Further, the integrated thin-film solar cell of the present invention
It is preferable that the length of the separation groove is longer than the length of the insulating separation region in the extending direction of the patterning line.

According to the above configuration, since the length of the separation groove is longer than that of the insulating separation region, both ends of the separation groove project from both ends of the insulating separation region. Therefore, when the separation groove is formed by laser light, even if there is a deviation in laser processing accuracy, insulation separation is reliably performed in the insulation separation region.

Further, the integrated thin-film solar cell of the present invention
The width in the direction orthogonal to the extending direction of the patterning line in the insulating isolation region is 100 μm or more and 1 m
m or less is desirable.

According to the above configuration, since the width of the insulating separation region is 100 μm or more, the insulation between the adjacent power generation regions is favorably isolated. In addition, since it is 1 mm or less, the non-power generation region can be suppressed to an area having no practical problem.

Further, the integrated thin-film solar cell of the present invention
It is desirable that the distance between the patterning lines is 15 mm or less.

According to the above configuration, since the interval between the patterning lines of the upper electrode layer is 15 mm or less, the resistance loss due to the upper electrode layer made of a transparent conductive film can be suppressed to a level that causes no practical problem. .

[0035]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments. Hereinafter, an integrated thin-film solar cell manufactured on a non-light-transmitting substrate will be described as an example, but the present invention can be similarly applied to an integrated thin-film solar cell manufactured on a light-transmitting substrate.

<First Embodiment> FIG. 1 is a vertical sectional view (FIG. 1 (a)) and a top perspective view (FIG. 1 (b)) of an integrated type thin film solar cell of the present embodiment. FIG. 2 shows a patterning shape of the lower electrode layer 12 in FIG. FIG. 3 is a longitudinal sectional view showing a manufacturing process of the integrated thin-film solar cell shown in FIG. Hereinafter, the integrated thin-film solar cell according to the present embodiment will be described in detail with reference to FIGS. 1, 2, and 3.

In this embodiment, a stainless steel substrate 11 whose surface is coated with a heat-resistant polymer resin such as a polymer resin containing polyimide as a main component is used as the light-impermeable substrate having an insulating surface. . And
As shown in FIG. 3B, Ag, ZnO or the like is continuously laminated as a lower electrode layer 12 on one surface of the substrate 11 by a sputtering method. In this case, the film forming means is not limited to the sputtering method, and may be, for example, an evaporation method.

Next, as shown in FIG.
Then, a division groove 14 is formed in the lower electrode layer 12 by a laser scribe method using No. 3, and is divided into strip-shaped unit cells by insulation (first patterning). Further, as shown in FIG. 3D, a rectangular groove 15 (FIG. 2) is formed immediately below a position in the lower electrode layer 12 where a separation groove is to be formed in the upper electrode layer.
) To form a rectangular insulating isolation region surrounded by the rectangular groove 15 and electrically insulated from the periphery. In the present embodiment, the width of the division groove 14 is set to 50 μm, and the interval is set to 10 mm. The width of the rectangular groove 15 is set to 50 μm.
m, and the interval (the width of the insulating isolation region) is 300 μm. The laser beam 13 is a second harmonic of a continuous wave Nd: YAG laser using a Q switch drive.
(SHG: wavelength λ = 532 nm) was used.

Here, the dividing groove 14 and the rectangular groove 15
Is formed by turning on / off each time the irradiation laser beam 13 is moved by a predetermined distance in the width direction of the insulating separation region. In the present embodiment, a high-speed mechanical shutter is provided in the optical path of the laser processing apparatus, and the irradiation laser light 13 is turned on / off by opening and closing the high-speed mechanical shutter according to the moving distance of the irradiation laser light 13. . The on / off control of the irradiation laser beam 13 can be performed by other methods, for example, a method of providing a high-speed shutter using an electro-optic effect in a laser light path, or irradiation of a Q switch control signal of a laser oscillator. There is a method of controlling according to the moving distance of the laser beam.

Next, as shown in FIG. 3E, as the photoelectric conversion layer 16, an amorphous semiconductor thin film, a microcrystalline semiconductor thin film, or the like is laminated by means such as plasma CVD (chemical vapor deposition).
Further, as shown in FIG. 3 (f), a laser beam 17 is irradiated from above the photoelectric conversion layer 16 to a position (second patterning line) which is parallel and close to the first patterning line 14, and Is selectively removed. Thus, a processing groove 18 for electrically connecting the upper electrode layer and the lower electrode layer 12 to be formed later is formed (second patterning).
Here, as a semiconductor thin film used as the photoelectric conversion layer 16, a silicon-based semiconductor or a compound semiconductor represented by hydrogenated amorphous silicon is used.

Next, as shown in FIG. 3G, ITO (indium tin oxide) is formed as the upper electrode layer 19 by a sputtering method or the like. The upper electrode layer 19 may be formed by other means such as a vapor deposition method, as in the case of the lower electrode layer 12. However, the film formation region of the upper electrode layer 19 is made smaller than the region of the photoelectric conversion layer 16 as shown in FIG. Thus, the upper electrode layer 1
This prevents direct contact between the lower electrode layer 9 and the lower electrode layer 12 at locations other than the processing groove 18.

Next, as shown in FIG. 3 (h), the upper electrode is placed at a position (third patterning line) parallel to the first patterning line 14 in the widthwise intermediate portion of the insulating isolation region in the lower electrode layer 12. Laser light 20 from above layer 19
Irradiates the upper electrode layer 19, the photoelectric conversion layer 16 and the lower electrode layer 12 at a time to form a separation groove 21 for insulating and separating the upper electrode layer 19 with a width of 50 μm (third). Patterning).

In this case, as shown in FIG. 1 (b), both ends of the separation groove 21 are projected by 100 μm outside the power generation effective area beyond both ends of the rectangular groove 15 of the lower electrode layer 12. By doing so, processing defects due to deviations in processing accuracy of the laser processing apparatus are prevented.

By the above procedure, an integrated thin-film solar cell having a sectional structure as shown in FIG. 1A and a plane shape of each layer as shown in FIG. 1B is formed. FIG.
As can be easily understood from (b), the width of the photoelectric conversion layer 16 is narrower than the width of the lower electrode layer 12, and the side ends of the photoelectric conversion layer 16 are set to both ends of the rectangular groove 15. Therefore, the power generation effective area is completely separated by the separation groove 21. At this time, since both ends of the separation groove 21 protrude beyond both ends of the rectangular groove 15, the power generation effective area is completely separated in the rectangular groove 15 even if there is a deviation in laser processing accuracy. The side edge of the upper electrode layer 19 is located inside the side edge of the photoelectric conversion layer 16. Therefore, the upper electrode layer 4 and the lower electrode layer 2 do not come into contact with each other except at the processing groove 18.

The output characteristic of the integrated thin-film solar cell having an effective power generation size of 300 mm × 300 mm formed according to the present embodiment is as follows: AM 1.5 (100 mW / cm ² );
0.66, maximum output = 8.3 W.

As described above, in the present embodiment,
When the dividing groove 14 is formed in the lower electrode layer 12 by the laser scribing method using the laser light 13 and is divided into strip-shaped unit cells by insulation, the separating groove for insulating and separating the upper electrode layer 19 later. The rectangular groove 15 is formed immediately below the position where the groove 21 is to be formed to form an insulating isolation region that is electrically insulated from the periphery. When the separation groove 21 is formed in the upper electrode layer 19, the upper electrode layer 19, the photoelectric conversion layer 16, and the lower electrode The layer 12 is removed at a time.

As described above, since the insulating isolation region which is electrically insulated from the periphery by the rectangular groove 15 is formed in the lower electrode layer 12, by forming the isolation groove 21 in the insulating isolation region, processing damage is caused. Can be stopped in the insulating isolation region and the upper region of the insulating isolation region, and the portion of the underlying photoelectric conversion layer 16 that functions as the power generation region is not damaged. Therefore, it is not necessary to carefully operate the laser beam 20 so as not to damage the photoelectric conversion layer 16 and the lower electrode layer 12 as in the related art, and high-speed and high-yield processing can be performed. Further, separation failure due to thermal influence on the peripheral portion of the insulating separation region due to irradiation of the laser beam 20 can be prevented, and characteristics can be improved. That is, a highly efficient integrated thin-film solar cell can be manufactured at low cost.

In the case where the above-mentioned separation groove 21 is formed,
The upper electrode layer 19 and the photoelectric conversion layer 1 are irradiated with the laser beam 20.
6 and the lower electrode layer 12 are collectively removed. Therefore, an integrated thin-film solar cell having excellent characteristics and excellent reproducibility can be obtained as compared with the conventional case where only the upper electrode layer 19 is insulated and separated.

Further, since the insulating isolation region is formed in a rectangular shape by the rectangular groove 15, the insulating isolation region having a width equal to or more than that of the case where the laser beam is scanned a plurality of times is replaced with the laser beam 20. Can be easily processed only by forming the rectangular groove 15 by making one round. Therefore, the number of times of scanning with laser light can be drastically reduced as a whole, and the processing time can be greatly reduced.

When the interval (10 mm in the present embodiment) between the divided grooves 14 is widened, the resistance of the transparent conductive film (ITO) as the upper electrode layer 19 is higher than the resistance of the metal. Therefore, the resistance loss increases. Therefore, it is desirable that the thickness be 15 mm or less. Moreover,
The width of the insulation isolation region (300 μm in this embodiment)
In the case where is narrow, the electrical isolation of the upper electrode layer 19 becomes insufficient due to the thermal influence on the periphery of the insulating isolation region due to the irradiation of the laser beam 13 and the like. Also,
On the other hand, if it is wide, the area of the integrated processing portion, which is a non-power generation region, increases, resulting in a decrease in solar cell characteristics. Therefore, it is desirable that the thickness be 100 μm or more and 1 mm or less.

<Second Embodiment> FIG. 4 is a longitudinal sectional view of an integrated thin-film solar cell according to the present embodiment. Also,
FIG. 5 shows a patterning shape of the lower electrode layer 32 in FIG. FIG. 6 is a longitudinal sectional view showing a manufacturing process of the integrated thin-film solar cell shown in FIG. Hereinafter, the integrated thin-film solar cell according to the present embodiment will be described in detail with reference to FIGS. 4, 5, and 6.

In this embodiment, an aluminum substrate 31 whose surface is coated with alumite by anodic oxidation is used as the light-impermeable substrate having an insulating surface. Then, as shown in FIG. 6B, Ag, Al, ZnO or the like is continuously laminated as a lower electrode layer 32 on one surface of the substrate 31 by a sputtering method.

Next, as shown in FIG.
A division groove 34 is formed in the lower electrode layer 32 by a laser scribe method using No. 3, and is divided into strip-shaped unit cells by insulation (first patterning). Further, the first
As in the case of the embodiment, as shown in FIG. 6D, a rectangular groove 35 (see FIG. 5) is formed immediately below a position where a separation groove is to be formed in the upper electrode layer in the lower electrode layer 32 later. Thus, an insulating isolation region electrically insulated from the periphery is formed.

Next, as shown in FIGS. 6E and 6F, the photoelectric conversion layer 36 and the upper electrode layer 37 are formed continuously. Then, as shown in FIG. 6 (g), a laser beam 39 is irradiated from above the upper electrode layer 37 to a position (second patterning line 38) that is parallel to and close to the first patterning line 34. 37 and the lower electrode layer 32 are electrically connected (second patterning).

Next, as shown in FIG. 6H, as in the case of the first embodiment, the lower electrode layer 32 is parallel to the first patterning line 34 at the widthwise intermediate portion of the insulating isolation region in the width direction. At a suitable position (third patterning line)
By irradiating the upper electrode layer 37 with a laser beam 40, the upper electrode layer 37, the photoelectric conversion layer 36, and the lower electrode layer 32 are collectively removed, and a separation groove 41 for insulating and separating the upper electrode layer 37 is formed. It is formed (third patterning).

The output characteristics of the integrated thin-film solar cell having an effective power generation size of 300 mm × 300 mm formed according to the present embodiment show a fill factor of AM 1.5 (100 mW / cm ² ).
0.64, maximum output = 8.2 W.

Note that the order of the second patterning and the third patterning is not limited to the above. Conversely, after the insulating separation process (third patterning) of the upper electrode layer 37 is performed, the upper electrode layer 37 is removed. Electrical connection processing (second patterning) between the lower electrode layer 32 and the lower electrode layer 32 may be performed. Alternatively, the second patterning and the third patterning may be performed simultaneously by providing two optical paths in a single laser processing apparatus. Further, the second patterning and the third patterning can be performed simultaneously with laser beams having different wavelengths.

In each of the above embodiments, the integrated thin-film solar cell manufactured on the light-impermeable substrate has been described.
However, the present invention can also be applied to an integrated thin-film solar cell fabricated on a light-transmitting substrate such as glass. In that case, an oxide transparent conductor film or a laminated film thereof is used as the lower electrode layer. Further, as the upper electrode layer, a reflective metal electrode film or a laminated film of these and a transparent conductive oxide film is used. Then, the light-transmitting substrate side (that is, the lower electrode layer side) may be the light incident side.

[0059]

As is apparent from the above description, the integrated thin-film solar cell of the present invention has a structure in which the lower electrode layer is provided immediately below the patterning line for electrically separating the upper electrode layer between the power generation regions adjacent to each other. Since the insulating isolation region electrically isolated from the surroundings is provided, damage to the photoelectric conversion layer caused when the upper electrode layer is insulated and isolated along the patterning line is limited to the upper region of the insulating isolation region. In addition, it is possible to make it less than the part functioning as the power generation area. Therefore, it is not necessary to carefully operate the laser beam so as not to damage the photoelectric conversion layer and the lower electrode layer as in the related art. That is, according to the present invention, it is possible to perform the insulating and separating process of the upper electrode at a high yield and at a high speed.

The integrated thin-film solar cell of the present invention
Along the patterning line for separating the upper electrode layer,
By providing a separation groove penetrating the upper electrode layer, the photoelectric conversion layer and the lower electrode layer, the upper electrode layer, the photoelectric conversion layer and the lower electrode layer are collectively removed to form a groove by removing the upper electrode layer. Insulation can be separated. In this case, the processing damage can be prevented from reaching the portion of the photoelectric conversion layer that functions as the power generation region. Therefore, an integrated thin-film solar cell with excellent reproducibility and excellent characteristics can be obtained as compared with the conventional case where only the upper electrode layer is insulated and separated.

The integrated thin-film solar cell of the present invention
If the separation groove is provided so as to pass through the insulating separation region,
In the case where the separation groove is formed by laser light, it is possible to reliably limit the thermal effect on the peripheral edge of the processing groove to the inside of the insulation separation region and the upper region of the insulation separation region. Therefore, it is possible to prevent separation failure due to the above-mentioned thermal influence and to improve characteristics and yield.

The integrated thin-film solar cell of the present invention
Assuming that the insulating isolation region of the lower electrode layer is a region surrounded by a closed loop-shaped insulating line, when forming the insulating isolation region with laser light, it is only necessary to draw a closed curve by making one round of the laser light. Therefore, the insulating isolation region having a certain width can be formed more easily than the case where the lower electrode layer is removed by scanning a plurality of times with laser light to remove the lower electrode layer. That is, according to the present invention, the number of times of scanning with laser light is drastically reduced as a whole, and the processing time can be greatly reduced.

The integrated thin-film solar cell of the present invention
If the length of the separation groove is longer than the length of the insulating separation region in the extending direction of the patterning line,
Both ends of the separation groove may protrude from both ends of the insulating separation region. Therefore, when the separation groove is formed by laser light, insulation separation can be reliably performed in the insulation separation region even if there is a deviation in laser processing accuracy. That is, according to the present invention, stable processing can be performed regardless of the processing accuracy and position reproducibility of the laser processing apparatus.

The integrated thin-film solar cell of the present invention
The width in the direction orthogonal to the extending direction of the patterning line in the insulating isolation region is 100 μm or more and 1 mm
By doing so, it is possible to satisfactorily insulate and separate the adjacent power generation regions, and to suppress the area of the non-power generation region to a level that causes no practical problem.

Further, the integrated thin film solar cell of the present invention
If the patterning line spacing is 15mm or less,
The resistance loss due to the upper electrode layer made of a transparent conductive film can be suppressed to a level that causes no practical problem.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view and a top perspective view of an integrated thin-film solar cell of the present invention.

FIG. 2 is a view showing a patterning shape of a lower electrode layer in FIG. 1;

FIG. 3 is a longitudinal sectional view showing a manufacturing process of the integrated thin-film solar cell shown in FIG.

FIG. 4 is a longitudinal sectional view of an integrated thin-film solar cell different from FIG.

FIG. 5 is a view showing a patterning shape of a lower electrode layer in FIG. 4;

FIG. 6 is a longitudinal sectional view showing a manufacturing process of the integrated thin-film solar cell shown in FIG.

FIG. 7 is a longitudinal sectional view of a conventional integrated thin-film solar cell.

FIG. 8 is a view showing a patterning shape of a lower electrode layer in FIG. 7;

FIG. 9 is a longitudinal sectional view showing a manufacturing process of the integrated thin-film solar cell shown in FIG.

[Explanation of symbols]

11, 31 ... substrate, 12, 32 ... lower electrode layer,
14, 34 ... division groove, 15, 35 ... rectangular groove,
16, 36: photoelectric conversion layer, 18: processed groove,
19, 37: Upper electrode layer, 21, 41
... separation grooves, 38 ... second patterning line (upper electrode layer /
Lower electrode layer connection line).

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroshi Taniguchi 22-22 Nagaikecho, Abeno-ku, Osaka City, Osaka F-term (reference) 5F051 EA01 EA02 EA09 EA10 EA11 EA16

Claims (7)

[Claims] A plurality of power generation regions formed by patterning a lower electrode layer, a photoelectric conversion layer, and an upper electrode layer sequentially laminated on a substrate having an insulating surface are connected in series on the substrate. In the integrated thin-film solar cell, the lower electrode layer is electrically separated from the surrounding lower electrode layer immediately below a patterning line for electrically separating the upper electrode layer between power generation regions adjacent to each other. An integrated thin-film solar cell, characterized in that an integrated insulating region is provided. 2. The integrated thin-film solar cell according to claim 1, wherein the patterning line for separating the upper electrode layer comprises:
An integrated thin-film solar cell, comprising a separation groove penetrating the upper electrode layer, the photoelectric conversion layer, and the lower electrode layer. 3. The integrated thin-film solar cell according to claim 2, wherein the separation groove is provided so as to pass through an insulating separation region of the lower electrode layer. 4. The integrated thin-film solar cell according to claim 1, wherein the insulating isolation region of the lower electrode layer is a region surrounded by a closed loop-shaped insulating line. An integrated thin-film solar cell characterized by the following. 5. The integrated thin-film solar cell according to claim 2, wherein a length of the isolation groove is longer than a length of the insulating isolation region in a direction in which the patterning line extends. An integrated thin-film solar cell, comprising: 6. The integrated thin-film solar cell according to claim 1, wherein a width of the insulating isolation region in a direction orthogonal to an extending direction of the patterning line is 100 μm or more. And 1m
m, wherein the thickness of the integrated thin-film solar cell is at most m. 7. The integrated thin-film solar cell according to claim 1, wherein an interval between the patterning lines is 15 mm or less.