JP5362833B2 - Solar cell module - Google Patents

Description

The present invention relates to a hot spot phenomenon at an end portion of a substrate and a solar cell module capable of preventing a substrate from being cracked due to the hot spot phenomenon.
This application claims priority based on Japanese Patent Application No. 2009-207168 for which it applied on September 8, 2009, and uses the content here.

  In recent years, solar cells are becoming more and more widely used from the viewpoint of efficient use of energy. In particular, a solar cell using a silicon single crystal is excellent in energy conversion efficiency per unit area. However, on the other hand, since a solar cell using a silicon single crystal uses a silicon wafer obtained by slicing a silicon single crystal ingot, a large amount of energy is consumed for manufacturing the ingot and the manufacturing cost is high. In particular, in the case of realizing a large area solar cell installed outdoors or the like, if a solar cell is manufactured using a silicon single crystal, it is considerably expensive at present. Therefore, solar cells using amorphous (amorphous) silicon thin films that can be manufactured at lower cost are widely used as low-cost solar cells.

  Amorphous silicon solar cells use a semiconductor film having a layer structure called a pin junction in which an amorphous silicon film (i-type) that generates electrons and holes when receiving light is sandwiched between p-type and n-type silicon films. . Electrodes are formed on both sides of the semiconductor film. Electrons and holes generated by sunlight move actively due to the potential difference between the p-type and n-type semiconductors, and this is continuously repeated, causing a potential difference between the electrodes on both sides.

As a specific configuration of such an amorphous silicon solar cell, for example, a transparent electrode such as TCO (Transparent Conductive Oxide) is formed on a glass substrate as a lower electrode, and a semiconductor film made of amorphous silicon, an upper electrode, A structure in which an Ag thin film or the like is formed is employed.
In an amorphous silicon solar cell including a photoelectric conversion body composed of such upper and lower electrodes and a semiconductor film, there is a problem that a potential difference is small and a resistance value is large only by depositing each layer uniformly over a wide area on a substrate. . Therefore, for example, an amorphous silicon solar battery is configured by forming solar cells in which photoelectric converters are electrically partitioned for each predetermined size and electrically connecting adjacent solar cells. .
Specifically, a groove called a scribe line (scribe line) is formed on a photoelectric conversion body uniformly formed in a large area on a substrate using a laser beam or the like to obtain a large number of strip-shaped solar cells. Thus, a structure in which the solar cells are electrically connected in series is employed.

By the way, in a thin film silicon solar cell in which a plurality of solar cells are connected in series, a plurality of solar cells are caused by dust being placed on the light incident surface or being covered with a shadow. When the output of a part of the cells is reduced, the output of the entire thin film silicon solar cell module is significantly reduced.
The solar cell whose output is further reduced becomes a resistance in a series circuit composed of a plurality of solar cells, and a voltage (bias voltage) is applied in the opposite direction to both ends of the solar cell to locally heat the phenomenon. (Hot spot phenomenon) occurs.
In particular, when a hot spot phenomenon occurs at the edge of the substrate, there is a problem that the substrate is easily broken.

Conventionally, a technique of providing a bypass diode for each thin film silicon solar cell module in order to avoid a decrease in output and a hot spot phenomenon is known (see, for example, Patent Document 1). In addition, a technique for partially providing a scribe line parallel to the scribe line is known (see, for example, Patent Document 2).
However, such a conventional technique has a problem that the number of manufacturing processes increases and a plurality of bypass diodes are connected, leading to an increase in cost.

JP 2001-068696 A Japanese Patent Laid-Open No. 2002-07642

  The present invention has been made to solve the above-described conventional problems, requires a complicated structure, and prevents the hot spot phenomenon at the edge of the substrate and the cracking of the substrate due to the hot spot phenomenon. An object of the present invention is to provide a solar cell module with high reliability.

  The solar cell module according to the first aspect of the present invention includes a substrate and a laminate including a first electrode layer, a power generation layer, and a second electrode layer sequentially stacked on the substrate, and includes two cell end portions. A power generation region having a plurality of solar cells formed by partitioning the power generation region by a scribe line and electrically connected in series, extending in a direction intersecting the scribe line, and at least the power generation layer And a plurality of grooves from which the second electrode layer has been removed, and extends from the cell end toward the center of the power generation region, and is ¼ of the length of the power generation region in a direction parallel to the scribe line. And a second area located between the first areas and in the center of the power generation region. In this configuration, the plurality of grooves include two first grooves formed in the first area and adjacent to the two cell end portions, and an interval between the cell end portion and the first groove is: It is smaller than the interval between the two first grooves.

  In the solar cell module of the first aspect of the present invention, the plurality of grooves include two second grooves formed in the first area and formed between the two first grooves, The distance between the cell end and the first groove or the distance between the first groove and the second groove is preferably smaller than the distance between the two second grooves.

  In the solar cell module according to the first aspect of the present invention, the plurality of grooves include a third groove formed in the second area, and an interval between the cell end and the first groove or the first groove. The distance between the second groove and the second groove is preferably smaller than the distance between the second groove and the third groove.

  In the solar cell module of the first aspect of the present invention, the plurality of grooves include a fourth groove formed in the second area and adjacent to the third groove, and the cell end portion and the first groove, The distance between the first groove and the second groove is preferably smaller than the distance between the third groove and the fourth groove.

  In the solar cell module according to the first aspect of the present invention, the plurality of grooves include a third groove formed in the second area, and an interval between the cell end and the first groove is the first groove. It is preferable that the distance is smaller than the distance between the groove and the third groove.

  In the solar cell module of the first aspect of the present invention, the plurality of grooves include a fourth groove formed in the second area and adjacent to the third groove, and the cell end portion and the first groove The interval is preferably smaller than the interval between the third groove and the fourth groove.

  In the solar cell module of the first aspect of the present invention, the plurality of grooves include a second groove formed in the first area, and a third groove and a fourth groove formed in the second area, The distance between the first groove and the second groove or the distance between the cell end and the first groove is preferably 70% or less of the distance between the third groove and the fourth groove.

  In the solar cell module according to the first aspect of the present invention, the distance between the first groove and the second groove or the distance between the cell end and the first groove is the third groove and the fourth groove. It is preferable that it is 50% or less of the interval.

  In the solar cell module according to the first aspect of the present invention, the plurality of grooves are fifth grooves formed away from the cell end by a distance larger than the distance between the first groove and the cell end. Among the plurality of grooves formed in the first area, the first groove is formed at a position closest to the cell end, and the first groove It is preferable that the distance between the first and second cell ends is smaller than the distance between the fifth groove and the sixth groove.

  In the solar cell module according to the first aspect of the present invention, the plurality of grooves are preferably formed by removing the first electrode layer, the power generation layer, and the second electrode layer.

  The solar cell module according to the second aspect of the present invention includes a substrate and a stacked body including a first electrode layer, a power generation layer, and a second electrode layer sequentially stacked on the substrate, and has a cell end. A region, a plurality of solar cells formed by partitioning the power generation region by a scribe line and electrically connected in series, extending in a direction intersecting the scribe line, at least the power generation layer and the And a plurality of grooves from which the second electrode layer has been removed. In this configuration, the plurality of grooves include two end groove closest to the cell end portion among the plurality of grooves, and the interval between the two end grooves and the cell end portion is 2 Less than the distance between the two end grooves.

  The solar cell module according to the second aspect of the present invention includes a substrate and a stacked body including a first electrode layer, a power generation layer, and a second electrode layer sequentially stacked on the substrate, and has a cell end. A region, a plurality of solar cells formed by partitioning the power generation region by a scribe line and electrically connected in series, extending in a direction intersecting the scribe line, at least the power generation layer and the And a plurality of grooves from which the second electrode layer has been removed. In this configuration, the plurality of grooves include an end groove closest to the cell end portion of the plurality of grooves and an inner groove formed at a position closer to the center of the substrate than the end groove. In addition, an interval between the end groove and the cell end is smaller than any one of an interval between the end groove and the inner groove and a plurality of inner grooves.

  In the solar cell module according to the second aspect or the third aspect of the present invention, it is preferable that a distance between the end groove and the cell end is the smallest among the plurality of grooves.

  In the solar cell module according to the second aspect or the third aspect of the present invention, the plurality of grooves may be formed by removing the first electrode layer, the power generation layer, and the second electrode layer. preferable.

In the solar cell module of the first aspect of the present invention, a plurality of grooves from which at least the power generation layer and the second electrode layer are removed are formed, a first electrode layer is formed on the bottom surface of the grooves, and the first electrode The layers are provided in regions located on both sides of the groove. For this reason, the first electrode layer electrically connects one region located on both sides of the groove and the other region. When the second electrode layer is separated by a groove, a portion having a low resistance (hereinafter also referred to as a low resistance portion) exists between the first electrode layer and the second electrode layer in one solar battery cell Even so, the total current flowing through the solar cell does not concentrate on the low resistance portion, and the occurrence of hot spots can be suppressed.
Furthermore, since the gap between the cell end and the first groove or the gap between the first groove and the second groove is smaller than the gap between the grooves, even when a low resistance portion exists, The amount of current that flows intensively in a part of the solar battery cell is further reduced, and the occurrence of a hot spot phenomenon at the edge of the substrate can be significantly suppressed. Thereby, the crack of the board | substrate resulting from a hot spot phenomenon can be prevented.
As a result, the present invention can provide a solar cell module that does not require a complicated structure and has excellent reliability.

  In the solar cell module according to the second aspect of the present invention, the plurality of grooves include two end grooves closest to the cell end portion among the plurality of grooves, and the two end grooves, The distance from the cell end is smaller than the distance between the two end grooves. For this reason, the effect similar to the solar cell module of a 1st aspect is acquired.

  Further, in the solar cell module according to the third aspect of the present invention, the plurality of grooves are formed at an end groove closest to the cell end portion among the plurality of grooves, and at a position closer to the center of the substrate than the end groove. The gap between the end groove and the cell end is smaller than any one of the gap between the end groove and the inner groove and the gap between the plurality of inner grooves. For this reason, the effect similar to the solar cell module of a 1st aspect is acquired.

It is a top view which shows the solar cell module of 1st Embodiment of this invention. It is a solar cell module of 1st Embodiment of this invention, Comprising: It is sectional drawing which shows the principal part of the solar cell module shown in FIG. It is a solar cell module of 1st Embodiment of this invention, Comprising: It is an expanded sectional view which shows the part shown by the code | symbol Z of FIG. 2A. In the solar cell module of 1st Embodiment of this invention, it is sectional drawing which shows the laminated body in which the structural defect exists. It is a top view which shows the modification of the solar cell module of 1st Embodiment of this invention. It is a top view which shows the solar cell module of 2nd Embodiment of this invention. It is a top view which shows the solar cell module of 3rd Embodiment of this invention. It is a top view which shows the solar cell module of 4th Embodiment of this invention.

Hereinafter, the best mode of a solar cell module according to the present invention will be described with reference to the drawings.
In the drawings used for the following description, the scale of each member is appropriately changed in order to make each member a recognizable size.
The technical scope of the present invention is not limited to the embodiments described below, and various modifications can be made without departing from the spirit of the present invention.

(First Embodiment of Solar Cell Module)
FIG. 1 is a plan view showing an amorphous silicon solar cell module 10A according to a first embodiment of the present invention. 2A is a cross-sectional view showing the layer structure of the solar cell module 10A of FIG. 1, and is a cross-sectional view taken along line X1-X2 in FIG. FIG. 2B is an enlarged cross-sectional view illustrating a portion indicated by a symbol Z in FIG. 2A.
The solar cell module 10 </ b> A of the first embodiment includes a substrate 11 and a power generation region A formed on the substrate 11. The power generation region A is configured by the laminate 12 and is divided into a plurality of solar cells 21 and 21 (partition elements) by the scribe line 20.
The stacked body 12 includes a first electrode layer 13, a power generation layer 14, and a second electrode layer 15 that are sequentially stacked on the first surface 11 a of the substrate 11. Further, the power generation layer 14 and the second electrode layer 15 are removed by the scribe line 20, that is, the solar cells 21 and 21 partitioned into a plurality by the scribe line 20 are formed. Further, the adjacent solar cells 21 and 21 are electrically connected in series in the direction indicated by the symbol C in FIG. The solar battery module 10A is configured by the plurality of solar battery cells 21 formed as described above.

In the power generation region A of the solar cell module 10A, it extends in a direction intersecting with the scribe lines 20 formed on both sides of the solar cells 21, 21. A plurality of grooves 22, 22 ... are formed. In the plurality of grooves 22 and 22, at least the power generation layer 14 and the second electrode layer 16 are removed.
The power generation region A has cell end portions 30 (30a, 30b) parallel to the direction indicated by the symbol C. In other words, the cell end portions 30 (30a, 30b) are both sides of the power generation region A and extend in a direction perpendicular to the scribe line 20.
The power generation area A of the solar cell module 10A has a first area A1 and a second area A2, as shown in FIG. The first area A1 is an area extending from each of the cell end portions 30 (30a, 30b) toward the center of the power generation area A in a direction parallel to the direction in which the scribe line 20 extends, It has a width of 1/4 with respect to the length. The second area A2 is a region formed between the two first areas A1. That is, the second area A2 has a width of 2/4 with respect to the length of the power generation area A.

  The plurality of grooves 22 and 22 are a first groove 22a formed in the first area A1, a second groove 22b located adjacent to (adjacent to) the first groove 22a, and a third groove formed in the second area A2. 22c and a fourth groove 22d located adjacent to (adjacent to) the third groove 22c. In the first embodiment, the groove located next to (adjacent to) the two cell end portions 30 (30a, 30b) is the first groove 22a. That is, in the power generation region A, two first grooves 22a are formed. In addition, two second grooves 22b are formed between the two first grooves 22a.

  Further, the interval between the cell end 30a and the first groove 22a close to the cell end 30a is smaller than the interval between the two first grooves 22a. Similarly, the distance between the cell end 30b and the first groove 22a close to the cell end 30b is smaller than the distance between the two first grooves 22a.

  Further, the distance between the cell end 30a and the first groove 22a close to the cell end 30a is smaller than the distance between the two second grooves 22b. Similarly, the interval between the cell end 30b and the first groove 22a close to the cell end 30b is smaller than the interval between the two second grooves 22b. The interval between the first groove 22a and the second groove 22b is smaller than the interval between the two second grooves 22b.

  Further, the distance between the cell end 30a and the first groove 22a close to the cell end 30a is smaller than the distance between the second groove 22b and the third groove 22c. Similarly, the distance between the cell end 30b and the first groove 22a close to the cell end 30b is smaller than the distance between the second groove 22b and the third groove 22c. Further, the distance between the first groove 22a and the second groove 22b is smaller than the distance between the second groove 22b and the third groove 22c.

  Further, the interval between the cell end 30a and the first groove 22a close to the cell end 30a is smaller than the interval between the third groove 22c and the fourth groove 22d. Similarly, the distance between the cell end 30b and the first groove 22a close to the cell end 30b is smaller than the distance between the third groove 22c and the fourth groove 22d. Further, the distance between the first groove 22a and the second groove 22b is smaller than the distance between the third groove 22c and the fourth groove 22d.

  Further, the distance between the cell end 30a and the first groove 22a close to the cell end 30a is smaller than the distance between the first groove 22a and the third groove 22c. Similarly, the distance between the cell end 30b and the first groove 22a close to the cell end 30b is smaller than the distance between the first groove 22a and the third groove 22c.

  Further, the interval between the cell end 30a and the first groove 22a close to the cell end 30a is smaller than the interval between the third groove 22c and the fourth groove 22d. Similarly, the distance between the cell end 30b and the first groove 22a close to the cell end 30b is smaller than the distance between the third groove 22c and the fourth groove 22d.

In the first embodiment, as shown in FIG. 1, two grooves (22a, 22b) are formed in the first area A1, but the present invention is not limited to this structure, and three grooves in the first area A1. Two or more grooves may be formed. In this case, an interval between a groove (first groove) arbitrarily selected from the plurality of grooves formed in the first area A1 and a groove (second groove) adjacent to the selected groove is the second area. It is smaller than the distance between the third groove 22c formed in A2 and the fourth groove 22d located adjacent to the third groove 22c.
In the first embodiment, the third groove 22c and the fourth groove 22d are formed in the second area A2, but the third groove 22c is an arbitrary one of the plurality of grooves formed in the second area A2. The fourth groove 22d is a groove adjacent to the selected groove.

In the first area A1 and the second area A2 having such a configuration, as shown in FIG. 2A, the grooves 22 (first groove, second groove, third groove, fourth groove) are formed in the power generation layer 14 and It is a groove formed by removing only the second electrode layer 15. The first electrode layer 13 is disposed on the bottom surface of the groove 22, and the first electrode layer 13 is exposed in the space in the groove 22. The first electrode layer 13 is formed in regions located on both sides of the groove 22. In other words, the first electrode layer 13 is located below the power generation layer 14 and is changed from the first cell region 41 to the second cell region 42 in the first cell region 41 and the second cell region 42 separated by the groove 22. It is provided so that it may extend toward. That is, the first electrode layer 13 electrically connects the regions 41 and 42 located on both sides of the groove 22.
The first cell region and the second cell region mean two regions divided by the groove 22. For example, in FIG. 2A, when reference numeral 42 is the first cell region, reference numeral 43 corresponds to the second cell region.

In such a configuration, the second electrode layer 15 is separated by the grooves 22. For this reason, for example, even when a low resistance portion (a portion having low resistance) exists between the first electrode layer 13 and the second electrode layer 15 in one solar battery cell 21, The total current flowing through the battery cell does not concentrate on the low resistance portion, and the occurrence of hot spots due to the current concentration can be suppressed.
In the solar cell 21, the first cell layer and the second cell region which are divided by the groove 22 are formed in the first cell layer 13 and the second cell region formed in the first cell region. The first electrode layer 13 is electrically connected. For this reason, for example, when the incident surface of the solar battery cell 21 is partially covered with a shadow, that is, in the region between the adjacent grooves 22 and 22 in the solar battery cell 21, Even if the two-electrode layer 15 is insulated, the current generated by the photoelectric conversion can flow from the first cell region to the second cell region adjacent to the groove 22. Specifically, in the structure in which a plurality of solar cells 21 are electrically connected in series, the current generated in the solar cells 21 (first cell region) located upstream or downstream in the current direction is expressed by the groove 22. To the second cell region adjacent to the first cell region.
Further, the interval between the adjacent grooves 22 and 22 in the end region (first area A1) of the substrate or the interval between the cell end 30 (30a and 30b) and the groove 22 adjacent to the cell end 30 is the center. This is smaller than the interval between adjacent grooves 22 in the region (second area A2). In other words, the width of the cell region (first cell region and second cell region) in the first area A1 is smaller than the width of the cell region (first cell region and second cell region) in the second area A2. Further, in the first area A1, a cell region 23 adjacent to the cell edge 30 and a cell region 24 formed between the cell region 23 and the second area A2 are formed. The width is smaller than the width of the cell region 24. In the second area A2, a cell region 25 having a width larger than the width of the cell region 23 is formed.
For this reason, even when the low resistance portion exists in the solar battery cell 21, the amount of current that flows intensively in a part of the solar battery cell 21 is further reduced, and the cell end 30 (30a, 30b) of the substrate is reduced. It is possible to remarkably suppress the occurrence of the hot spot phenomenon at a position close to).
Therefore, the solar cell module 10A having the above configuration can prevent the substrate from being cracked due to the hot spot phenomenon.
As a result, the present invention can provide a solar cell module that does not require a complicated structure and has excellent reliability.

In the above configuration, the distance between the first groove 22a and the second groove 22b or the distance between the cell end 30 (30a, 30b) and the first groove 22a is 70, which is the distance between the third groove 22c and the fourth groove 22d. % Or less is preferable.
By satisfying this condition, the amount of current that flows intensively in a part of the solar battery cells 21 is further reduced, so that it is possible to improve the effect of preventing the substrate from cracking due to the hot spot phenomenon described above.
The distance between the first groove 22a and the second groove 22b or the distance between the cell end 30 (30a, 30b) and the first groove 22a is 50% or less of the distance between the third groove 22c and the fourth groove 22d. It is preferable that In this case, the effect of preventing cracking of the substrate due to the hot spot phenomenon described above can be further enhanced.
However, increasing the number of grooves 22 causes a decrease in the power generation area or an increase in the number of manufacturing steps. For this reason, it is not preferable to increase the number of grooves 22 and reduce the interval between all the grooves 22 and 22.

In the above-described configuration, the plurality of grooves 22, 22... Have a cell end portion 30 (30 a, 30 b) that is larger than the distance (the width of the cell region 23) between the first groove 22 a and the cell end portion 30 (30 a, 30 b). And a fourth groove 22d (sixth groove) adjacent to the fifth groove 22g. In this configuration, among the plurality of grooves formed in the first area A1, the first groove 22a is formed at a position closest to the cell end 30 (30a, 30b), and the first groove 22a and the cell end 30 (30a) are formed. 30b) is smaller than the distance between the fifth groove 22g and the fourth groove 22d.
By satisfying this condition, the effect of preventing cracking of the substrate due to the hot spot phenomenon described above can be further improved.
In the first embodiment, the fourth groove 22d and the sixth groove coincide with each other, but the number of grooves formed in the second area A2 is larger than the number of grooves shown in FIG. May not match the fourth groove 22d and the sixth groove.

The board | substrate 11 is comprised with the insulating material which is excellent in the transmittance | permeability of sunlight, such as glass or transparent resin, and has durability.
In this solar cell module 10 </ b> A, sunlight S is incident on the second surface 11 b located on the opposite side of the substrate 11 from the first surface 11 a.

  The first electrode layer 13 (lower electrode) is made of a transparent conductive material, for example, a light transmissive metal oxide such as TCO or ITO.

For example, as shown in FIG. 2B, the power generation layer 14 (semiconductor layer) has a pin junction structure in which an i-type amorphous silicon film 14i is sandwiched between a p-type amorphous silicon film 14p and an n-type amorphous silicon film 14n. To do.
When sunlight is incident on the power generation layer 14, electrons and holes are generated. The electrons and holes move actively due to the potential difference between the p-type amorphous silicon film 14p and the n-type amorphous silicon film 14n, and this is repeated continuously. As a result, a potential difference is generated between the first electrode layer (lower electrode) 13 and the second electrode layer (upper electrode) 15 (photoelectric conversion).

  In the present invention, a configuration in which a buffer layer (not shown) is disposed between the power generation layer 14 and the second electrode layer 15 disposed on the power generation layer 14 may be employed. By disposing a buffer layer (not shown) between the power generation layer 14 and the second electrode layer 15, silicon can be prevented from diffusing from the power generation layer 14 to the second electrode layer 15, and silicon reacts. Can be suppressed. Such a buffer layer (not shown) is made of, for example, ZnO.

  The second electrode layer (upper electrode) 15 is made of a conductive light reflecting film such as Ag (silver) or Al (aluminum). The second electrode layer 15 can be formed by, for example, a sputtering method.

In the power generation region A configured by such a laminated body 12, the power generation layer 14 and the second electrode layer 15 are partially removed by a scribe line 20 (scribe line). Thereby, the electric power generation area | region A is divided | segmented into many solar cells 21,21 ... which have a strip-shaped external shape, for example.
These solar cells 21, 21... Are electrically partitioned from each other. The adjacent solar cells 21 are electrically connected in series.
Thereby, in the electric power generation area | region A comprised with the laminated body 12, all the photovoltaic cells 21, 21, ... are connected in series, and the electric current of a high electric potential difference can be taken out.
The scribe line 20 is formed, for example, by forming the laminated body 12 uniformly on the first surface 11a of the substrate 11 and then forming grooves in the power generation layer 14 and the second electrode layer 16 at a predetermined interval by a laser beam or the like. The
FIG. 3 shows an example of a structure in which all the solar cells 21, 21... Are electrically arranged in series and the scribe line 20 is formed.
3 is a cross-sectional view of a position corresponding to the line Y1-Y2 shown in FIG.

As shown in FIG. 3, in the solar cells 21, 21..., For example, it is generated by a structural defect B <b> 1 generated by contamination in the power generation layer 14 or a fine pinhole in the power generation layer 14. In some cases, defects such as the structural defect B2 may occur.
Such structural defects B1 and B2 locally short-circuit (leak) between the first electrode layer 13 and the second electrode layer 16 to reduce power generation efficiency.

Further, in the step of forming the scribe line 20, as shown in FIG. 3, the metal constituting the second electrode layer 15 is melted because the position irradiated with the laser is shifted from the target position. In some cases, a defect such as a structural defect B3 generated when the molten metal flows down into the groove of the scribe line 20 may occur.
Such a structural defect B3 locally short-circuits (leaks) between the first electrode layer 13 and the second electrode layer 15 to reduce power generation efficiency.

Furthermore, the solar battery cell 21 whose output is reduced due to the second surface 11 b being covered with a shadow or the like becomes a resistance in a series circuit constituted by the plurality of solar battery cells 21. For this reason, a voltage (bias voltage) is applied in the opposite direction to both ends of the solar battery cell 21, and the phenomenon in which the voltage concentrates on a portion having a low resistance such as the above-described defect and is locally heated (hot spot phenomenon). Get up.
In particular, in the conventional solar battery cell, when the hot spot phenomenon occurs in a region near the end of the substrate 11 where the narrow solar battery cell 21 is disposed, there is a problem that the substrate 11 is broken. .

  On the other hand, in the solar cell module 10A of the first embodiment, a plurality of grooves from which at least the power generation layer 14 and the second electrode layer 16 are removed in the direction intersecting the scribe line 20 of the solar cells 21, 21. 22, 22... Are formed. Furthermore, the power generation area A of the solar cell module 10A has the first area A1 and the second area A2 as described above. Further, at least one of the interval between the groove 22 arbitrarily selected in the first area A1 and the groove 22 adjacent to the selected groove and the interval between the cell end 30 and the groove 22 adjacent to the cell end 30 is selected. One is smaller than the distance between the arbitrarily selected groove 22 formed in the second area A2 and the groove 22 adjacent to the selected groove 22.

Since the solar cell module 10A of the first embodiment has the above-described configuration, the problem that current flows in a concentrated manner in the end region of the substrate 11 is reduced, and the occurrence of a hot spot phenomenon can be suppressed.
Thereby, it is possible to prevent the substrate 11 from being cracked due to the hot spot phenomenon. Therefore, according to the present invention, a solar cell module excellent in reliability without requiring a complicated structure can be obtained.

(Modification of First Embodiment of Solar Cell Module)
In 1st Embodiment mentioned above, as shown in FIG. 1, although the cell area | region 23 (narrow area | region of the photovoltaic cell 21) adjacent to the cell edge part 30 of the board | substrate 11 was demonstrated, The present invention is not limited to this structure. For example, as shown in FIG. 4, the width of the cell region 24 may be smaller than the width of the cell region 23. That is, a structure in which the narrow region of the solar battery cell 21 is separated from the cell end 30 in the first area A1 may be employed.

  A protective layer (not shown) may be formed on the second electrode layer (upper electrode) 15. Examples of such a protective layer (not shown) include Ti and the like.

(Method for manufacturing solar cell module)
Next, a method for manufacturing the solar cell module 10A having the above-described configuration will be described.
First, an insulating transparent substrate 11 having a transparent conductive film formed thereon is prepared as the first electrode layer 13. Next, as shown in FIG. 3, a first electrode separation groove for separating the first electrode layer 13 is formed. Next, each of the p-type amorphous silicon film 14p, the i-type amorphous silicon film 14i, and the n-type amorphous silicon film 14n of the power generation layer 14 is formed on the first electrode layer 13 in the plasma CVD reaction chamber.

The p-type amorphous silicon film 14p is formed using a plasma CVD method in an individual reaction chamber. As conditions for forming the p-layer of amorphous silicon (a-Si), for example, the temperature of the substrate 11 is set to 180 to 200 ° C., the power supply frequency is set to 13.56 MHz, and the reaction chamber pressure is set to 70 to 120 Pa. The reaction gas flow rate is set to 300 sccm for monosilane (SiH ₄ ), 2300 sccm for hydrogen (H ₂ ), 180 sccm for diborane (B ₂ H ₆ / H ₂ ) using hydrogen as a diluent gas, and 500 sccm for methane (CH ₄ ). Conditions are used.

The i-type amorphous silicon film 14i is formed using a plasma CVD method in an individual reaction chamber. As conditions for forming the i-layer of amorphous silicon (a-Si), for example, the temperature of the substrate 11 is set to 180 to 200 ° C., the power supply frequency is set to 13.56 MHz, and the reaction chamber pressure is set to 70 to 120 Pa. Then, a condition in which monosilane (SiH ₄ ) is set to 1200 sccm as the reaction gas flow rate is used.

Further, the n-type amorphous silicon film 14n is formed using a plasma CVD method in an individual reaction chamber. As conditions for forming the n layer of amorphous silicon (a-Si), for example, the temperature of the substrate 11 is set to 180 to 200 ° C., the power supply frequency is set to 13.56 MHz, and the pressure in the reaction chamber is set to 70 to 120 Pa. Then, a condition in which phosphine (PH ₃ / H ₂ ) using hydrogen as a diluent gas is set to 200 sccm as the flow rate of the reaction gas is used.

Next, as shown in FIG. 3, the power generation layer separation grooves are formed by irradiating the power generation layer 14 with, for example, a laser beam.
Next, the second electrode layer 15 is formed on the power generation layer 14. The material of the second electrode layer 15 is filled in the power generation layer separation groove, and the first electrode layer 13 is connected to the second electrode layer 15.
The second electrode layer 15 is formed (deposited) using, for example, an inline type sputtering apparatus. Thereafter, for example, a laser beam is irradiated toward the power generation layer 14 and the second electrode layer 15 to form the scribe line 20.
As a result, a large number of strip-shaped solar cells 21 are formed.
The solar cells 21, 21... Are electrically partitioned from each other, and the solar cells 21 adjacent to each other are electrically connected in series, for example.
Further, as shown in FIG. 1, the grooves 22 are formed by irradiating the power generation layer 14 and the second electrode layer 15 with, for example, a laser beam in a direction perpendicular to the live line 20. As a result, as shown in FIG. 2A, cell regions 41, 42, and 43 (first cell region and second cell region) are formed.
As a result, in each of the solar cells 21, the power generation layer 14 and the second electrode layer 15 are not formed, and a plurality of cells electrically connected by the groove portion where the first electrode layer 13 is exposed. Divided into regions.
Thereby, a solar cell module 10A as shown in FIGS. 1, 2A, and 2B is obtained.

According to the manufacturing method described above, it is possible to easily reduce the inconvenience that current flows in the end region of the substrate 11 and reduce the occurrence of the hot spot phenomenon. It can be manufactured stably.
Therefore, the manufacturing method described above contributes to the manufacture of a solar cell module that can prevent the substrate 11 from cracking due to the hot spot phenomenon.

  In the first embodiment described above, the plurality of grooves 22 and 22 are formed by removing the power generation layer 14 and the second electrode layer 16. The present invention does not limit the structure of such grooves, and the plurality of grooves 22, 22 may be formed by removing the first electrode layer 13, the power generation layer 14, and the second electrode layer 16. Good. In this case, a first electrode separation groove for separating the first electrode layer 13 is formed along the pattern of the plurality of grooves 22 and 22.

(Second Embodiment of Solar Cell Module)
FIG. 5 is a plan view showing an amorphous silicon solar cell module 10C according to the second embodiment of the present invention.
In FIG. 5, the same members as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted or simplified.
In the power generation region A of the solar cell module 10C, a plurality of end grooves 22e, 22e (22) extending in the direction C intersecting with the scribe lines 20 formed on both sides of the solar cells 21, 21,. ing. At least the power generation layer 14 and the second electrode layer 16 are removed in the end grooves 22e and 22e. A plurality of end arrays 50 are arranged along the direction C between the end grooves 22e and the cell end portions 30 (30a, 30b). Each of the plurality of end arrays 50 constitutes a part of the solar battery cell 21. A plurality of inner arrays 51 are arranged along the direction C so as to be located at the center of the substrate 11 between the end array 50 near the cell end 30a and the end array 50 near the cell end 30b. Has been. Each of the plurality of inner arrays 51 constitutes a part of the solar battery cell 21.
Further, the width of the end array 50 in the direction parallel to the direction in which the scribe line 20 extends is smaller than the width of the inner array 51. In other words, the distance between the end groove 22e and the cell end 30 (30a, 30b) is smaller than the distance between the two end grooves 22e, 22e. Further, the distance between the end groove 22e and the cell end 30 (30a, 30b) is the smallest among the plurality of grooves 22.
In the second embodiment, the same effect as that of the first embodiment described above can be obtained.

(Third embodiment of solar cell module)
FIG. 6 is a plan view showing an amorphous silicon solar cell module 10D according to the third embodiment of the present invention.
In FIG. 6, the same members as those in the first embodiment and the second embodiment are denoted by the same reference numerals, and the description thereof is omitted or simplified.
In the power generation region A of the solar cell module 10D, a plurality of inner sides are located between the end array 50 close to the cell end 30a and the end array 50 close to the cell end 30b so as to be located at the center of the substrate 11. The arrays 51a and 51b are arranged along the direction C. Each of the plurality of inner arrays 51 a and 51 b constitutes a part of the solar battery cell 21.
Further, an inner groove 22f (22) is formed between the inner array 51a and the inner array 51b, and the inner groove 22f divides one inner array 51 into two inner arrays 51a and 51b. That is, in the solar cell module 10D, one inner groove 22f is formed.
The width of the end array 50 in the direction parallel to the direction in which the scribe line 20 extends is smaller than the width of the inner arrays 51a and 51b. In other words, the distance between the end groove 22e and the cell end 30 (30a, 30b) is smaller than the distance between the end groove 22e and the inner groove 22f. Further, the distance between the end groove 22e and the cell end 30 (30a, 30b) is the smallest among the plurality of grooves 22.
In the third embodiment, the same effect as that of the first embodiment described above can be obtained.

(4th Embodiment of a solar cell module)
FIG. 7 is a plan view showing an amorphous silicon solar cell module 10E according to the fourth embodiment of the present invention.
In FIG. 7, the same members as those in the first embodiment, the second embodiment, and the third embodiment are denoted by the same reference numerals, and the description thereof is omitted or simplified.
In the power generation region A of the solar cell module 10E, a plurality of inner sides are arranged between the end array 50 close to the cell end 30a and the end array 50 close to the cell end 30b so as to be located at the center of the substrate 11. The arrays 51c and 51d are arranged along the direction C. Each of the plurality of inner arrays 51 c and 51 d constitutes a part of the solar battery cell 21.
Further, an inner groove 22f (22) is formed between the inner array 51d and the inner array 51c near the cell end 30a, and between the inner array 51d and the inner array 51c near the cell end 30b. Is formed with an inner groove 22f (22). The inner groove 22f divides one inner array 51 into three inner arrays 51c and 51d. That is, in the solar cell module 10E, two inner grooves 22f are formed.
Further, the width of the end array 50 in the direction parallel to the direction in which the scribe line 20 extends is smaller than the width of the inner array 51c. In other words, the distance between the end groove 22e and the cell end 30 (30a, 30b) is smaller than the distance between the two inner grooves 22f. Further, the distance between the end groove 22e and the cell end 30 (30a, 30b) is the smallest among the plurality of grooves 22.
In the fourth embodiment, the same effect as that of the first embodiment described above can be obtained.

As mentioned above, although embodiment of the solar cell module of this invention has been described, this invention is not limited to the example mentioned above, In the range which does not deviate from the meaning of invention, it can change suitably.
In the second embodiment, the third embodiment, and the fourth embodiment described above, the plurality of grooves 22 and 22 are formed by removing the power generation layer 14 and the second electrode layer 16. The present invention does not limit the structure of such grooves, and the plurality of grooves 22, 22 may be formed by removing the first electrode layer 13, the power generation layer 14, and the second electrode layer 16. Good.

The present invention is widely applicable to solar cell modules.
That is, in the said embodiment, although the example in which this invention was applied to the solar cell module which a photovoltaic cell consists of a silicon-type thin film was explained in full detail, this invention does not limit the photovoltaic cell which consists of a silicon-type thin film. For example, the present invention can be applied to a solar battery cell made of a compound thin film, an organic thin film, or crystalline silicon.

  DESCRIPTION OF SYMBOLS 10 Solar cell module, 11 board | substrate, 12 laminated body, 13 1st electrode layer, 14 Power generation layer, 15 2nd electrode layer, 20 Scribe line, 21 Solar cell, 22 groove | channel, 22a 1st groove | channel, 22b 2nd groove | channel, 22c 3rd groove | channel, 22d 4th groove | channel, A1 1st area, A2 2nd area.

Claims (4)

A solar cell module,
A substrate,
A power generation region having two cell edges, which is constituted by a laminate including a first electrode layer, a power generation layer, and a second electrode layer sequentially stacked on the substrate;
A plurality of solar cells formed by partitioning the power generation region by scribe lines and electrically connected in series;
A plurality of grooves extending in a direction intersecting the scribe line and at least the power generation layer and the second electrode layer are removed;
A first area extending from the cell end toward the center of the power generation region and having a width that is ¼ of the length of the power generation region in a direction parallel to the scribe line;
A second area located between the first areas and in the center of the power generation area;
Including
The interval between the grooves adjacent to each other in the first area, or the interval between the cell end and the groove adjacent to the cell end is smaller than the interval between the grooves adjacent to each other in the second area. > A solar cell module characterized by that. The solar cell module according to claim 1,
The plurality of grooves are formed in the first area and adjacent to the two cell ends, the first groove, the second groove formed in the first area, and the second area. Including a third groove and a fourth groove,
The distance between the first groove and the second groove or the distance between the cell end and the first groove is 70% or less of the distance between the third groove and the fourth groove. Solar cell module. The solar cell module according to claim 2 , wherein
The distance between the first groove and the second groove or the distance between the cell end and the first groove is 50% or less of the distance between the third groove and the fourth groove. Solar cell module. The solar cell module according to claim 1,
The plurality of grooves are formed by removing the first electrode layer, the power generation layer, and the second electrode layer.

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