JP2006165338A - Integrated thin-film solar cell and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an integrated thin-film solar cell capable of reducing a non-power generation region after preventing occurrence of short circuit between electrodes, and to provide its manufacturing method. <P>SOLUTION: The integrated thin-film solar cell (1) includes a substrate (10), and a first electrode film (11), a semiconductor film (12), and a second electrode film (13) which are successively laminated on the substrate (10). Each of a plurality of unit cells (20) is composed of a laminated body including the first electrode film (11) divided by a first dividing groove (11a), the semiconductor film (12) divided by a second dividing groove (12a), and the second electrode film (13) divided by a third dividing groove (13a). A part of the substrate (10) at the side end (111a) located at least on the second dividing groove (12a) side is removed in the first dividing groove (11a). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an integrated thin-film solar cell in which thin-film solar cells including a thin-film light absorption layer are connected in series, and a method for manufacturing the same.

  Conventionally, various integrated thin film solar cells in which a plurality of thin film solar cells (unit cells) are connected in series have been proposed (see, for example, Patent Document 1).

  A conventional method for manufacturing an integrated thin film solar cell will be described with reference to FIGS. First, as shown in FIG. 7A, a first electrode film 102 made of Mo or the like is formed on a substrate 101 made of a glass substrate or the like by a sputtering method or the like. Subsequently, a dividing groove 102a penetrating the first electrode film 102 is formed using a laser or the like.

Next, as shown in FIG. 7B, a semiconductor film 103 is formed on the first electrode film 102 and in the dividing groove 102a by means of vapor deposition, sputtering, chemical deposition, or the like. As the semiconductor film 103, for example, CuInSe ₂ (hereinafter also referred to as “CIS”) which is a compound semiconductor (chalcopyrite structure semiconductor) containing a group Ib element, a group IIIb element, and a group VIb element, or Ga is dissolved therein. Further, CuIn _(1-X) Ga _X Se ₂ (X is a real number between 0 <X <1, hereinafter, also referred to as “CIGS”) can be used.

  Next, as shown in FIG. 7C, the division grooves 103a are formed through the semiconductor film 103 and along the division grooves 102a by a mechanical patterning method or the like.

  Subsequently, as shown in FIG. 7D, a second electrode film 104 is formed on the semiconductor film 103 and in the dividing grooves 103a by a sputtering method or the like.

Then, as shown in FIG. 7E, the dividing groove 104a is formed through the second electrode film 104 and the semiconductor film 103 and along the dividing groove 103a by a mechanical patterning method or the like. As a result, the integrated thin film solar cell 100 in which the second electrode film 104 of each unit cell 105 and the first electrode film 102 of the unit cell 105 adjacent thereto are connected and the plurality of unit cells 105 are connected in series is obtained. can get.
Japanese Patent Publication No. 4-72392

  However, in the manufacturing method described above, when the dividing groove 103a is formed (see FIG. 7C), a part 103b of the semiconductor film 103 blocking the dividing groove 102a may be peeled off. In particular, when the semiconductor film 103 containing CIS or CIGS is used, a part of the semiconductor film 103 (part corresponding to the dividing groove 103a) is removed by a mechanical patterning method, so that peeling due to chipping is likely to occur. When a part 103b of the semiconductor film 103 that closes the dividing groove 102a is peeled, when the second electrode film 104 is laminated, the adjacent first electrode films 102 are short-circuited via the second electrode film 104 or adjacent to each other. In some cases, the second electrode films 104 are short-circuited via the first electrode film 102. In order to avoid the short circuit, a part of the semiconductor film 103 is usually removed by providing a margin when the dividing groove 103a is formed. Therefore, in the conventional integrated thin-film solar cell 100, the non-power generation region is increased, and improvement of the photoelectric conversion efficiency per unit area is hindered.

  In order to solve the above problems, the present invention provides an integrated thin-film solar cell that can reduce a non-power generation region while preventing a short circuit between electrodes, and a method for manufacturing the same.

The integrated thin film solar cell of the present invention is an integrated thin film solar cell including a plurality of unit cells connected in series and a substrate provided with the plurality of unit cells,
Including a first electrode film, a semiconductor film and a second electrode film sequentially stacked on the substrate;
Each of the plurality of unit cells includes the first electrode film divided by a first dividing groove, the semiconductor film divided by a second dividing groove, and the second electrode film divided by a third dividing groove. And a laminated body including
The first dividing groove penetrates the first electrode film and is formed by removing a part of the substrate.
The second dividing groove penetrates the semiconductor film and is formed along the first dividing groove,
The third divided groove penetrates the second electrode film and is formed along the second divided groove,
A part of the substrate is removed from at least a side end located on the second dividing groove side in the first dividing groove.

The manufacturing method of the integrated thin film solar cell of the present invention is as follows.
Forming a first electrode film on the substrate;
Penetrating the first electrode film and removing a part of the substrate to form a first dividing groove in which a part of the substrate is removed at least at one of the side edges,
Forming a semiconductor film on the first electrode film and in the first dividing groove;
Forming a second dividing groove along a side end portion penetrating the semiconductor film and having a portion of the substrate removed in the first dividing groove;
Forming a second electrode film on the semiconductor film and in the second dividing groove;
It is a manufacturing method of the integrated thin film solar cell which penetrates the said 2nd electrode film and forms a 3rd division groove along the said 2nd division groove.

  According to the integrated thin film solar cell and the method of manufacturing the same of the present invention, when forming the second divided groove, it is possible to prevent part of the semiconductor film formed in the first divided groove from being peeled off. It is possible to provide an integrated thin film solar cell that can reduce the non-power generation region while preventing a short circuit therebetween. Thereby, for example, the photoelectric conversion efficiency per unit area of the integrated thin film solar cell can be improved.

  The integrated thin-film solar battery of the present invention is an integrated thin-film solar battery including a plurality of unit cells connected in series and a substrate provided with the plurality of unit cells. An electrode film, a semiconductor film, and a second electrode film are included.

The substrate is not particularly limited as long as electrical insulation can be maintained between the first electrode film and the semiconductor film. For example, a glass substrate, a substrate in which an electrical insulating film is formed on the surface of a metal layer, a metal layer A substrate or the like whose surface is electrically insulated can be used. As a specific example of a substrate in which an electric insulating film is formed on the surface of a metal layer, an inorganic material such as SiO ₂ or Al ₂ O ₃ melted at a temperature of 400 ° C. or higher is coated on a metal layer made of stainless steel or the like. By doing so, the thing etc. which formed the vitreous electrical insulating film are mentioned. Specific examples of the substrate on which the surface of the metal layer is electrically insulated include a sol / gel substrate and a metal cage substrate. Moreover, what is necessary is just to let the thickness of a board | substrate be 50-500 micrometers, for example.

As materials for the first electrode film and the second electrode film, electrode materials generally used for solar cells can be used. For example, when the second electrode film is an electrode on the light incident side, Mo, Al, etc. can be used as the material of the first electrode film, and indium oxide-tin (ITO), SnO can be used as the material of the second electrode film. ₂ , ZnO or the like can be used. In this case, the thickness of the first and second electrode films may be set to, for example, 0.3 to 2 μm and 0.1 to 1 μm, respectively.

The semiconductor film is not particularly limited, and a semiconductor film for a solar cell generally used for a solar cell can be used. In particular, as a semiconductor film, a P-type semiconductor layer made of a compound semiconductor film containing a group Ib element, a group IIIb element and a VIb group element, and an N-type semiconductor layer made of a compound semiconductor film containing a group IIb element and a group VIb element. Is preferably used because an integrated thin film solar cell with high photoelectric conversion efficiency and little deterioration in photoelectric conversion efficiency due to light irradiation or the like can be formed. As the P-type semiconductor layer, for example, a semiconductor layer made of CIS, CIGS, CuInS ₂ or the like can be used. As the N-type semiconductor layer, for example, a semiconductor layer made of CdS, ZnO, ZnMgO, Zn (O, OH), Zn (O, OH, S), or the like can be used. The thicknesses of the P-type semiconductor layer and the N-type semiconductor layer may be set to 0.5 to 3 μm and 0.01 to 0.1 μm, respectively.

  Further, as the semiconductor film used in the present invention, in addition to those described above, for example, an amorphous silicon thin film, a polycrystalline silicon thin film, a microcrystalline silicon thin film, etc. may be used, and these are used in tandem. Also good. When an amorphous silicon thin film is used, the thickness of the thin film may be, for example, 0.3 to 2.0 μm. Moreover, when using a polycrystalline-silicon thin film, the thickness of the said thin film should just be 2-20 micrometers, for example. Moreover, when using a microcrystalline silicon thin film, the thickness of the said thin film should just be 0.5-20 micrometers, for example.

  Each of the plurality of unit cells includes a first electrode film divided by the first dividing groove, a semiconductor film divided by the second dividing groove, and a second electrode film divided by the third dividing groove. It is comprised from the laminated body containing. The first dividing groove is formed by penetrating the first electrode film and removing a part of the substrate, and the second dividing groove is formed by penetrating the semiconductor film and along the first dividing groove. The third dividing groove penetrates through the second electrode film and is formed along the second dividing groove. Note that the groove widths of the first, second, and third divided grooves may be, for example, 10 to 200 μm, 10 to 200 μm, and 5 to 100 μm, respectively. Moreover, what is necessary is just to let the width | variety of each unit cell be 2-10 mm, for example. The number of unit cells is not particularly limited, and may be set as appropriate according to the required power generation amount.

  In the first divided groove, a part of the substrate is removed from at least a side end portion (hereinafter also referred to as “first side end portion”) located on the second divided groove side. Accordingly, when the semiconductor film is formed in the manufacturing process of the integrated thin film solar cell, the thickness of the semiconductor film formed on the outer edge portion on the first side end portion side in the first dividing groove is reduced (or the outer edge). The semiconductor film is intermittently formed in the portion). Therefore, when forming the second divided groove, part of the semiconductor film formed in the first divided groove (for example, peeling due to chipping) is less likely to occur. Therefore, it is not necessary to provide a margin when forming the second divided groove. As a result, the integrated thin film solar cell of the present invention can reduce the non-power generation region while preventing a short circuit between the electrodes. For example, the photoelectric conversion efficiency per unit area of the integrated thin film solar cell is improved. Can be made.

  Further, the integrated thin film solar cell of the present invention has different groove depths at both ends of the first divided groove in the cross section in the width direction of the first divided groove, and the second divided groove has a groove depth in the first divided groove. It is good also as an integrated-type thin film solar cell formed along the side edge part of the deeper side. It is because the effect mentioned above can be exhibited more reliably. Further, the groove depth of the first divided groove in the above configuration is from the side end portion (hereinafter also referred to as “second side end portion”) having a shallower groove depth in the cross section in the width direction of the first divided groove. It may be continuously deeper toward the first side end. Of the semiconductor film, the region formed in the first dividing groove and immediately above the first dividing groove is formed in an inclined shape inclined from the second side end portion toward the first side end portion. This is because peeling of a part of the semiconductor film due to the above can be prevented more reliably.

Further, in order to exhibit the above-described effect more reliably, the integrated thin film solar cell of the present invention has a groove depth of the first side end portion in the first divided groove as D, and the thickness of the first electrode film and the first When the thickness of the semiconductor film on one electrode film is T ₁ and T ₂ , the value of (D−T ₁ ) may be 30% to 200% of the value of (T ₂ −T ₁ ). preferable.

  The integrated thin film solar cell of the present invention may be an integrated thin film solar cell in which the first dividing groove is closed with a semiconductor film. This is because a short circuit between the electrodes can be prevented more reliably.

  The manufacturing method of the integrated thin film solar cell of this invention is a suitable manufacturing method for manufacturing the integrated thin film solar cell of this invention mentioned above. Therefore, each component described below is the same as that of the integrated thin film solar cell of the present invention described above.

  In the method for manufacturing an integrated thin film solar cell of the present invention, first, a first electrode film is formed on a substrate by, for example, sputtering.

  Subsequently, the first electrode film is penetrated and a part of the substrate is removed to form a first divided groove in which a part of the substrate is removed at least at one of the side end portions. The formation of the first division groove may be performed by, for example, laser beam irradiation.

  Next, a semiconductor film is formed on the first electrode film and in the first division groove by, for example, a vapor deposition method, a sputtering method, a chemical deposition method, or the like.

  Then, a second divided groove is formed along a side end portion (first side end portion) penetrating the semiconductor film and from which a part of the substrate is removed in the first divided groove. The formation of the second dividing groove may be performed by, for example, a mechanical patterning method.

  Then, after forming the second electrode film on the semiconductor film and in the second divided groove by a sputtering method or the like, the third divided groove is formed through the second electrode film and along the second divided groove. The formation of the third dividing groove may be performed by, for example, a mechanical patterning method. By the above method, the integrated thin film solar cell of the present invention that can reduce the non-power generation region while preventing a short circuit between the electrodes can be easily manufactured.

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

[First Embodiment]
First, the integrated thin film solar cell according to the first embodiment of the present invention will be described. FIG. 1 to be referred to is a cross-sectional view of the integrated thin film solar cell according to the first embodiment.

  As shown in FIG. 1, the integrated thin-film solar cell 1 according to the first embodiment includes a substrate 10, a first electrode film 11, a semiconductor film 12, and a second electrode film 13 that are sequentially stacked on the substrate 10. Including. As the semiconductor film 12, for example, a P-type semiconductor layer made of a compound semiconductor film containing a group Ib element, a group IIIb element, and a VIb group element, and an N-type semiconductor made of a compound semiconductor film containing a group IIb element and a group VIb element. A laminate in which layers are laminated can be used.

  Each of the plurality of unit cells 20 provided on the substrate 10 includes a first electrode film 11 divided by the first dividing groove 11a, a semiconductor film 12 divided by the second dividing groove 12a, and a third It is comprised from the laminated body containing the 2nd electrode film 13 divided | segmented by the division | segmentation groove | channel 13a. The first dividing groove 11a penetrates the first electrode film 11 and is formed by removing a part of the substrate 10, the second dividing groove 12a penetrates the semiconductor film 12, and The third dividing groove 13 a is formed along the second dividing groove 12 a and penetrates the second electrode film 13 and the semiconductor film 12. And the 2nd electrode film 13 of each unit cell 20 and the 1st electrode film 11 of the unit cell 20 adjacent to this are connected, and the integrated thin film solar cell 1 in which the several unit cell 20 was connected in series is formed. Has been.

  Further, in the integrated thin film solar cell 1, the groove depths at both ends of the first dividing groove 11a are different in the cross section in the width direction of the first dividing groove 11a, and the second dividing groove 12a is in the first dividing groove 11a. It is formed along the first side end portion 111a which is the side end portion having the deeper groove depth. Thereby, when the semiconductor film 12 is formed in the manufacturing process of the integrated thin film solar cell 1 described later, the thickness of the semiconductor film 12 formed on the outer edge portion on the first side end portion 111a side in the first dividing groove 11a is reduced. It becomes thinner (or the semiconductor film 12 is intermittently formed at the outer edge). Therefore, when forming the second dividing groove 12a, a part of the semiconductor film 12 formed in the first dividing groove 11a is hardly peeled off (for example, peeling due to chipping). Therefore, it is not necessary to provide a margin when forming the second dividing groove 12a. Thereby, since the integrated thin film solar cell 1 can reduce a non-power generation area | region, after preventing the short circuit between electrodes, it can improve the photoelectric conversion efficiency per unit area, for example.

  Further, the groove depth of the first divided groove 11a is such that, in the cross section in the width direction of the first divided groove 11a, the first side end part 111a from the second side end part 112a which is the side end part having the shallower groove depth. It is getting deeper continuously. Thereby, in the semiconductor film 12, the region formed in the first dividing groove 11a and immediately above the first dividing groove 11a is inclined so as to incline from the second side end 112a toward the first side end 111a. Therefore, part of the semiconductor film 12 due to chipping, for example, can be more reliably prevented.

  Further, in the integrated thin film solar cell 1, the first dividing groove 11 a is closed with the semiconductor film 12. Thereby, the short circuit between electrodes can be prevented more reliably.

In order to exhibit the above-described effect more reliably, the integrated thin-film solar cell 1 has a groove depth of the first side end portion 111a as D, and the thickness of the first electrode film 11 and the thickness on the first electrode film 11 the thickness of the semiconductor film 12 is taken as _{T 1} and _{T 2,} respectively, is preferably 200% or less than 30% of the values of _{(D-T 1)} is _(T 2 -T _1).

  Although the integrated thin film solar cell according to the first embodiment of the present invention has been described above, the present invention is not limited to the above embodiment. For example, the third dividing groove that divides the second electrode film may be a dividing groove that does not penetrate the semiconductor film and penetrates only the second electrode film. Moreover, the part from which a part of board | substrate is removed should just be a side edge part located in the 2nd division groove side in a 1st division groove. Therefore, as shown in FIG. 2, the groove depth of the first dividing groove 11a is not continuously increased from the second side end portion 112a toward the first side end portion 111a, and changes intermittently. The integrated thin film solar cell 2 may be used.

  Next, a method for manufacturing the integrated thin film solar cell 1 according to the first embodiment will be described. 3A to E to be referred to are cross-sectional views showing respective steps in the manufacturing method of the integrated thin-film solar cell 1. The same components as those in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted.

  First, as shown in FIG. 3A, a first electrode film 11 is formed on a substrate 10 by sputtering a conductive material such as Mo.

  Subsequently, as shown in FIG. 3B, the first electrode film 11 is penetrated and a part of the substrate 10 is removed to form the first divided grooves 11a having different groove depths at both ends in the cross section in the width direction. To do. A detailed method of forming the first dividing groove 11a will be described later.

  Next, as shown in FIG. 3C, the semiconductor film 12 is formed on the first electrode film 11 and in the first divided groove 11a by, for example, vapor deposition, sputtering, chemical deposition, or the like. At this time, the thickness of the semiconductor film 12 formed on the outer edge portion ED on the first side end portion 111a side in the first dividing groove 11a is reduced (or the semiconductor film 12 is intermittently formed in the outer edge portion ED). ). In addition, when using the laminated body by which the P-type semiconductor layer and the N-type semiconductor layer were laminated | stacked as the semiconductor film 12, after laminating | stacking the P-type semiconductor layer used as a light absorption layer, it is a window on a P-type semiconductor layer. An N-type semiconductor layer to be a layer may be stacked.

  Then, as shown in FIG. 3D, the second divided groove 12a is formed along the first side end portion 111a in the first divided groove 11a while penetrating the semiconductor film 12. The formation of the second dividing groove 12a may be performed by, for example, a mechanical patterning method. At this time, as described above, the thickness of the semiconductor film 12 formed in the outer edge portion ED shown in FIG. 3C is thin (or the semiconductor film 12 is intermittently formed in the outer edge portion ED). Part of the semiconductor film 12 formed in the one-divided groove 11a is hardly peeled off (for example, peeling due to chipping).

  3E, after the second electrode film 13 is formed by sputtering a transparent conductive material such as ITO on the semiconductor film 12 and in the second dividing groove 12a, A third divided groove 13a is formed through the semiconductor film 12 and along the second divided groove 12a. The formation of the third dividing groove 13a may be performed by, for example, a mechanical patterning method. With the above method, the integrated thin-film solar cell 1 that can reduce the non-power generation region while preventing a short circuit between the electrodes can be easily manufactured.

  Next, in the process shown in FIG. 3B of the manufacturing method of the integrated thin-film solar cell 1 described above, a method of forming the first dividing groove 11a will be described with reference to the drawings. FIG. 4A to be referred to is a schematic diagram showing a process of forming the first divided groove 11a by laser beam irradiation.

  As shown in FIG. 4A, the laser beam LB emitted from the laser oscillator 30 is shaped by the expander lens 31 and a part thereof is cut by the slit 32. Then, the cut laser beam LB is reflected by the mirror 33, further condensed by the processing lens 34, and then irradiated onto the first electrode film 11. At this time, the laser beam LB after being cut has an asymmetric laser output distribution (a hatched portion) as shown in FIG. 4B. Therefore, for example, if a portion of the laser beam LB having a high energy (LBh in FIG. 4B) is used to remove a portion corresponding to the first side end 111a in the first dividing groove 11a, as shown in FIG. 3B. A first dividing groove 11a having a shape can be formed. The method for forming the first divided groove 11a is not limited to this, and for example, a method of irradiating two laser beams in an overlapping manner, a method of irradiating a laser beam obliquely, or the like may be used.

  As another method for forming the first divided groove 11a, as shown in FIG. 5A, a part of the region AR in which the first divided groove 11a is formed on the first electrode film 11 is matched with the wavelength of the laser beam LB. After applying the light absorbing material 40 (for example, carbon), a method of irradiating the laser beam LB on the light absorbing material 40 and the first electrode film 11 as shown in FIG. 5B may be used.

Next, an example of the integrated thin-film solar cell 1 when the value of (D−T ₁ ) / (T ₂ −T ₁ ) × 100 (hereinafter referred to as TA) is changed will be described. First, using a 10 cm square substrate as the substrate 10, the integrated thin film solar cells 1 of Examples 1 to 3 were manufactured by the method described above. At this time, the number of unit cells 20 was 18 in all cases. Further, TA was 20% for Example 1, TA was 100% for Example 2, and TA was 300% for Example 3. In Example 1, when the second divided groove 12a was formed, a 50 μm margin was provided between the first divided groove 11a and the semiconductor film 12 so as not to peel off. Example 2 and Example 3 were manufactured without providing a margin.

Next, the short-circuit current (Isc), the open circuit voltage (Voc), the fill factor (FF), and the photoelectric conversion efficiency (Eff) were measured for the integrated thin-film solar cells 1 of Examples 1 to 3. In addition, the measurement was performed using 100 mW / cm ² pseudo sunlight of air mass (AM) 1.5. The results are shown in Table 1.

As shown in Table 1, in Example 1, Isc and Eff were lower than in Example 2. In Example 1, since a margin was provided when forming the second dividing groove 12a, the non-power generation region was larger (that is, the power generation region was smaller) and Isc and Eff were reduced compared to Example 2. It is done. On the other hand, FF and Eff of Example 3 were lower than those of Example 2. In Example 3, since the groove depth D of the first side end portion 111a is deeper than that in Example 2, the second electrode film 13 is partially formed in a part of the region where the second electrode film 13 straddles the first divided groove 11a. The film thickness becomes thin. Therefore, it is considered that the series resistance is increased and FF and Eff are decreased. These results, the integrated thin-film solar cell 1 is preferably 200% or less than 30% of the values of _{(D-T 1)} is _(T 2 -T _1).

[Second Embodiment]
Next, an integrated thin film solar cell according to a second embodiment of the present invention will be described. FIG. 6 to be referred to is a cross-sectional view of the integrated thin film solar cell according to the second embodiment. The same components as those in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in FIG. 6, the integrated thin film solar cell 3 according to the second embodiment is an integrated thin film solar cell using an amorphous silicon thin film 51 and a polycrystalline silicon thin film 52 as semiconductor films in tandem. A substrate 10 made of a transparent glass substrate or the like, and a first electrode film 50, an amorphous silicon thin film 51, a polycrystalline silicon thin film 52, and a second electrode film 53 are sequentially stacked on the substrate 10. A transparent high electric resistance film may be disposed as an intermediate layer between the amorphous silicon thin film 51 and the polycrystalline silicon thin film 52.

Each of the amorphous silicon thin film 51 and the polycrystalline silicon thin film 52 is a semiconductor thin film having a PIN junction. As the first electrode film 50, a transparent electrode film made of, for example, SnO ₂ or ITO can be used. Further, as the second electrode film 53, for example, an electrode film made of Al or the like can be used. Other configurations are the same as those of the integrated thin-film solar cell 1 (see FIG. 1) according to the first embodiment described above. Therefore, since the integrated thin film solar cell 3 according to the second embodiment can reduce the non-power generation region after preventing a short circuit between the electrodes, as in the integrated thin film solar cell 1, for example, a unit area The hit photoelectric conversion efficiency can be improved.

  Note that the integrated thin film solar cell 3 according to the second embodiment has a wavelength when forming the second divided groove in the step of FIG. 3D of the manufacturing method of the integrated thin film solar cell 1 according to the first embodiment described above. It can be manufactured by the same method as in the first embodiment, except that the second harmonic of a 0.532 μm Nd: YAG laser is used. When forming the second dividing groove, it is only necessary to irradiate the second harmonic of the Nd: YAG laser from the substrate 10 side so as to penetrate only the amorphous silicon thin film 51 and the polycrystalline silicon thin film 52. Also in this case, as in the first embodiment, since the thin films 51 and 52 formed on the outer edge portion on the first side end portion side in the first dividing groove are thin (or in the outer edge portion, the thin film 51 and 52 are formed intermittently), it becomes difficult for some of the thin films 51 and 52 formed in the first dividing groove to be peeled off.

1 is a cross-sectional view of an integrated thin film solar cell according to a first embodiment of the present invention. It is sectional drawing which shows the modification of the integrated thin film solar cell which concerns on 1st Embodiment of this invention. AE is sectional drawing which shows each process in the manufacturing method of the integrated thin film solar cell which concerns on 1st Embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure for demonstrating the one part process in the manufacturing method of the integrated thin film solar cell which concerns on 1st Embodiment of this invention, A is a schematic diagram which shows the process of forming a 1st division groove by laser beam irradiation. B is a graph showing a laser output distribution of a laser beam irradiated onto the first electrode film. A and B are sectional views for explaining a process of forming the first division groove of the integrated thin film solar cell according to the first embodiment of the present invention. It is sectional drawing of the integrated thin film solar cell which concerns on 2nd Embodiment of this invention. AE is sectional drawing which shows each process in the manufacturing method of the conventional integrated thin film solar cell.

Explanation of symbols

1, 2, 3 Integrated thin-film solar cell 10 Substrate 11, 50 First electrode film 11a First divided groove 12 Semiconductor film 12a Second divided groove 13, 53 Second electrode film 13a Third divided groove 20 Unit cell 30 Laser oscillator 31 Expander Lens 32 Slit 33 Mirror 34 Processing Lens 40 Light Absorbing Material 51 Amorphous Silicon Thin Film 52 Polycrystalline Silicon Thin Film 111a First Side End 112a Second Side End LB Laser Beam

Claims (9)

An integrated thin-film solar cell including a plurality of unit cells connected in series and a substrate provided with the plurality of unit cells,
Including a first electrode film, a semiconductor film and a second electrode film sequentially stacked on the substrate;
Each of the plurality of unit cells includes the first electrode film divided by a first dividing groove, the semiconductor film divided by a second dividing groove, and the second electrode film divided by a third dividing groove. And a laminated body including
The first dividing groove penetrates the first electrode film and is formed by removing a part of the substrate.
The second dividing groove is formed through the semiconductor film and along the first dividing groove;
The third divided groove penetrates the second electrode film and is formed along the second divided groove,
A part of the substrate is removed from at least a side end located on the second dividing groove side in the first dividing groove. In the cross section in the width direction of the first divided groove, the groove depths at both ends of the first divided groove are different,
2. The integrated thin-film solar cell according to claim 1, wherein the second divided groove is formed along a side end portion having a deeper groove depth in the first divided groove.   In the cross-section in the width direction of the first divided groove, the groove depth of the first divided groove is continuously from the side end portion with the shallower groove depth toward the side end portion with the deeper groove depth. The integrated thin film solar cell according to claim 2, which is deep. The groove depth at the side end located on the second dividing groove side in the first dividing groove is D, and the thickness of the first electrode film and the thickness of the semiconductor film on the first electrode film are T, respectively. _2. The integrated thin film solar cell according to claim 1, wherein the value of (D−T ₁ ) is 30% or more and 200% or less of the value of (T ₂ −T ₁ ) when ₁ and T ₂ are set.   The integrated thin-film solar cell according to claim 1, wherein the first dividing groove is closed with the semiconductor film. The semiconductor film is a laminate composed of a P-type semiconductor layer and an N-type semiconductor layer,
The P-type semiconductor layer is composed of a compound semiconductor film containing a group Ib element, a group IIIb element, and a group VIb element,
The integrated thin film solar cell according to claim 1, wherein the N-type semiconductor layer is composed of a compound semiconductor film containing a Group IIb element and a Group VIb element.   2. The integrated thin film solar cell according to claim 1, wherein the semiconductor film includes at least one semiconductor film for a solar cell selected from an amorphous silicon thin film, a polycrystalline silicon thin film, and a microcrystalline silicon thin film. Forming a first electrode film on the substrate;
Penetrating the first electrode film and removing a part of the substrate to form a first dividing groove in which a part of the substrate is removed at least at one of the side edges,
Forming a semiconductor film on the first electrode film and in the first dividing groove;
Forming a second dividing groove along a side end portion penetrating the semiconductor film and having a portion of the substrate removed in the first dividing groove;
Forming a second electrode film on the semiconductor film and in the second dividing groove;
A method for manufacturing an integrated thin film solar cell, wherein the third divided groove is formed along the second divided groove while penetrating the second electrode film.   The method for manufacturing an integrated thin-film solar cell according to claim 8, wherein the first dividing groove is formed by laser beam irradiation.

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