JP2012175065A - Solar battery and solar battery module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solar battery having an improved photoelectric conversion efficiency.SOLUTION: A solar battery 1 comprises: a solar battery substrate 10 having an n-type surface 10an and a p-type surface 10ap on one main surface 10a; an n-side electrode 21n disposed above the n-type surface 10an; and a p-side electrode 21p disposed above the p-type surface 10ap. The p-side electrode 21p includes a p-side bus bar section 21p1 extending along a first direction x, and a plurality of p-side finger sections 21p2 extending from the p-side bus bar section 21p1. The n-side electrode includes an n-side bus bar section 21n1 extending along the first direction x, and a plurality of n-side finger sections 21n2 extending from the n-side bus bar section 21n1. The n-side bus bar 21n1 and the p-side bus bar section 21p1 are arranged along the first direction x.

Description

  The present invention relates to a back junction solar cell and a solar cell module including the solar cell.

  Conventionally, for example, the following Patent Document 1 proposes a so-called back junction type solar cell in which p-type and n-type semiconductor regions are arranged on the back side of the solar cell. In this back junction solar cell, it is not necessary to provide an electrode on the light receiving surface side. For this reason, in the back junction solar cell, the light receiving efficiency can be increased. Therefore, higher photoelectric conversion efficiency can be realized.

JP 2010-80887 A

  In recent years, the request | requirement of the photoelectric conversion efficiency improvement with respect to a solar cell has further increased.

  This invention is made | formed in view of such a point, The objective is to provide the solar cell which has the improved photoelectric conversion efficiency.

  The solar cell according to the present invention includes a solar cell substrate, an n-side electrode, and a p-side electrode. The solar cell substrate includes an n-type surface and a p-type surface on one main surface. The n-side electrode is disposed on the n-type surface. The p-side electrode is disposed on the p-type surface. The p-side electrode has a p-side bus bar portion and a plurality of p-side finger portions. The p-side bus bar portion extends along the first direction. The plurality of p-side finger portions extend from the p-side bus bar portion. The n-side electrode has an n-side bus bar portion and a plurality of n-side finger portions. The n-side bus bar portion extends along the first direction. The plurality of n-side finger portions extend from the n-side bus bar portion. The plurality of n-side finger portions are interleaved with the plurality of p-side finger portions. The n-side bus bar portion and the p-side bus bar portion are arranged along the first direction.

  The solar cell module according to the present invention includes a plurality of solar cells and a wiring material. The wiring member electrically connects a plurality of solar cells. The solar cell includes a solar cell substrate, an n-side electrode, and a p-side electrode. The solar cell substrate includes an n-type surface and a p-type surface on one main surface. The n-side electrode is disposed on the n-type surface. The p-side electrode is disposed on the p-type surface. The p-side electrode has a p-side bus bar portion and a plurality of p-side finger portions. The p-side bus bar portion extends along the first direction. The plurality of p-side finger portions extend from the p-side bus bar portion. The n-side electrode has an n-side bus bar portion and a plurality of n-side finger portions. The n-side bus bar portion extends along the first direction. The plurality of n-side finger portions extend from the n-side bus bar portion. The plurality of n-side finger portions are interleaved with the plurality of p-side finger portions. The n-side bus bar portion and the p-side bus bar portion are arranged along the first direction.

  ADVANTAGE OF THE INVENTION According to this invention, the solar cell which has the improved photoelectric conversion efficiency can be provided.

1 is a schematic cross-sectional view of a solar cell module according to a first embodiment. It is the schematic plan view seen from the back surface side of the solar cell in 1st Embodiment. FIG. 3 is a schematic cross-sectional view taken along line III-III in FIG. 2. It is a schematic plan view of the solar cell string in the first embodiment. It is a schematic plan view of the solar cell in the second embodiment. It is a schematic plan view of the solar cell in the third embodiment. It is schematic-drawing sectional drawing of the solar cell in 4th Embodiment.

  Hereinafter, an example of the preferable form which implemented this invention is demonstrated. However, the following embodiments are merely examples. The present invention is not limited to the following embodiments.

  Moreover, in each drawing referred in embodiment etc., the member which has a substantially the same function shall be referred with the same code | symbol. The drawings referred to in the embodiments and the like are schematically described, and the ratio of the dimensions of the objects drawn in the drawings may be different from the ratio of the dimensions of the actual objects. The dimensional ratio of the object may be different between the drawings. The specific dimensional ratio of the object should be determined in consideration of the following description.

(First embodiment)
FIG. 1 is a schematic cross-sectional view of a solar cell module 3 according to the first embodiment. The solar cell module 3 includes a plurality of solar cell strings 2. Each of the plurality of solar cell strings 2 includes a plurality of solar cells 1 arranged along one direction (x direction). The plurality of solar cell strings 2 are arranged in parallel at predetermined intervals along another direction (y direction) orthogonal to one direction (x direction). The plurality of solar cells 1 are electrically connected by the wiring material 31. Specifically, a plurality of solar cells 1 are electrically connected in series or in parallel by electrically connecting the electrodes of the solar cells 1 adjacent in the x direction by the wiring material 31.

  The wiring member 31 and the solar cell 1 are bonded by an adhesive layer (not shown) made of resin. The adhesive layer may be made of only a resin. The adhesive layer may have anisotropic conductivity including a resin layer and a conductive material dispersed in the resin layer. Specific examples of the conductive material include metal particles, alloy particles, and conductive materials having a minute size such as insulating particles coated with a metal or an alloy. When the adhesive layer is made only of a resin adhesive, the wiring material 31 and the electrode of the solar cell 1 are bonded so as to be in direct contact.

  A first protective member 34 is disposed on the back side of the plurality of solar cells 1. On the other hand, a second protective member 35 is disposed on the light receiving surface side of the plurality of solar cells 1. A sealing material 33 is provided between the solar cell 1 and the first protective member 34 and between the solar cell 1 and the second protective member 35. The plurality of solar cells 1 are sealed between the first protective member 34 and the second protective member 35 by the sealing material 33.

  The material of the sealing material 33 and the 1st and 2nd protection members 34 and 35 is not specifically limited. The sealing material 33 can be formed of, for example, a resin such as ethylene / vinyl acetate copolymer (EVA) or polyvinyl butyral (PVB).

  The 1st protection member 34 distribute | arranged to the back side can be comprised with the resin film which interposed metal foil, such as glass, a resin film, and aluminum foil, for example.

  The 2nd protection member 35 distribute | arranged to the light-receiving surface side can be comprised with the board | plate body which has translucency, such as translucent glass and resin, for example.

  The solar cell module 3 is made of a metal such as Al attached to the outer periphery of a laminate having a first protective member 34, a sealing material 33, a plurality of solar cells 1, a sealing material 33, and a second protective member 35. A frame (not shown) may be provided. The solar cell module 3 may include a terminal box provided on the surface of the first protection member 34 for taking out the output of the solar cell 1 to the outside.

  FIG. 2 is a schematic plan view seen from the back surface side of the solar cell 1 in the first embodiment. 3 is a schematic cross-sectional view taken along line III-III in FIG.

  The solar cell 1 is a so-called back junction solar cell. The solar cell 1 has a solar cell substrate 10. The solar cell substrate 10 is a member that generates carriers such as electrons and holes by receiving light. The solar cell substrate 10 has a light receiving surface 10b and a back surface 10a. The n-type surface 10an and the p-type surface 10ap are exposed on the back surface 10a. A passivation layer or an AR coating layer may be provided on the light receiving surface 10b. A light shielding material such as metal is not provided on the light receiving surface 10b. Therefore, in the solar cell 1 according to the present embodiment, light is incident on substantially the entire surface or the entire surface of the light receiving surface 10b.

  Each of the light receiving surface 10b and the back surface 10a has a rectangular shape. Here, the “rectangle” includes a rectangle in which at least one of the four corners is chamfered or R-chamfered.

  In the present embodiment, the solar cell substrate 10 includes a substrate 11a, a p-type amorphous semiconductor layer 11p, and an n-type amorphous semiconductor layer 11n. The substrate 11a is made of a crystalline semiconductor having one conductivity type. Specifically, in the present embodiment, the substrate 11a is configured by an n-type single crystal silicon substrate. For this reason, in this embodiment, a hole becomes a minority carrier.

  Each of the p-type amorphous semiconductor layer 11p and the n-type amorphous semiconductor layer 11n is disposed on the back surface of the substrate 11a. The p-type surface 10ap is constituted by the surface of the p-type amorphous semiconductor layer 11p. The n-type surface 10an is constituted by the surface of the n-type amorphous semiconductor layer 11n.

  The p-type amorphous semiconductor layer 11p can be made of, for example, p-type amorphous silicon containing hydrogen. The n-type amorphous semiconductor layer 11n can be made of, for example, n-type amorphous silicon containing hydrogen. The solar cell substrate 10 is disposed between each of the p-type amorphous semiconductor layer 11p and the n-type amorphous semiconductor layer 11n and the substrate 11a so as not to substantially contribute to power generation (for example, several An i-type amorphous semiconductor layer (Ř250Å) may be further provided. In that case, the i-type amorphous semiconductor layer can be made of, for example, i-type amorphous silicon containing hydrogen. By providing the i-type amorphous semiconductor layer, the junction characteristics between each of the p-type amorphous semiconductor layer 11p and the n-type amorphous semiconductor layer 11n and the substrate 11a can be improved. A solar cell having improved photoelectric conversion efficiency is provided.

  On the back surface 10a of the solar cell substrate 10, a p-side electrode 21p and an n-side electrode 21n are arranged. The p-side electrode 21p is disposed on the p-type surface 10ap. The n-side electrode 21n is disposed on the n-type surface 10an. In this embodiment, since the substrate 11a is composed of an n-type single crystal silicon substrate, holes become minority carriers and electrons become majority carriers. Therefore, the p-side electrode 21p collects minority carriers, and the n-side electrode 21n collects majority carriers.

  The material of the p-side electrode 21p and the n-side electrode 21n is not particularly limited as long as it is a conductive material. Each of the p-side electrode 21p and the n-side electrode 21n is, for example, a metal such as silver, copper, aluminum, titanium, nickel, or chromium, an alloy containing one or more of these metals, TCO (Transparent Conductive Oxide), or the like. Can be formed. In addition, each of the p-side electrode 21p and the n-side electrode 21n may be configured by a stacked body of a plurality of conductive layers made of, for example, the above metal, alloy, or TCO.

  Each of the p-side electrode 21p and the n-side electrode 21n can be formed using various methods such as sputtering, vapor deposition, screen printing, or plating.

  The p-side electrode 21p includes a p-side bus bar portion 21p1, a plurality of p-side finger portions 21p2, and a p-side finger portion 21p3. The n-side electrode 21n includes an n-side bus bar portion 21n1 including a pad portion 21n3 and a plurality of n-side finger portions 21n2.

  The p-side bus bar portion 21p1 has a linear shape extending along the x direction (one direction) that is the direction in which the side 10a1 of the back surface 10a extends. The p-side bus bar portion 21p1 is provided with its area shifted to one side (x1 side) in the x direction of the back surface 10a.

  Each of the plurality of p-side finger portions 21p2 extends continuously from the p-side bus bar portion 21p1. The predetermined p-side finger portion 21p2 has a proximal end portion 21p21, a connection portion 21p22, and a distal end portion 21p23. In the present embodiment, specifically, among the plurality of p-side finger portions 21p2, all the finger portions excluding the finger portions located in the central portion in the x direction are composed of the base end portion 21p21 and the connection portion 21p22. And a tip 21p23. These bus bar portions are connected to the p-side bus bar portion 21p1 at the base end portion 21p21. The proximal end portion 21p21 extends along the y direction perpendicular to the x direction. The connection portion 21p22 connects the base end portion 21p21 and the tip end portion 21p23. The connection part 21p22 includes a bent part or a curved part. Specifically, in the present embodiment, the connection portion 21p22 includes a bent portion. The tip portion 21p23 extends along the y direction. The tip portion 21p23 faces the n-side bus bar portion 21n1 in the y direction. That is, the plurality of p-side electrodes 21p include U-shaped finger portions. In this embodiment, the finger part located in the center part of the x direction among several p side finger parts 21p2 is linear.

  The plurality of p-side finger portions 21p2 include a relatively long p-side finger portion and a relatively short p-side finger portion. The relatively long p-side finger portion is thinner than the relatively short p-side finger portion. Specifically, in the present embodiment, among the plurality of p-side finger portions 21p2, the p-side finger portion located on the outer side is longer and thinner, and the p-side finger portion located on the inner side is shorter and thicker.

  The p-side finger part 21p3 is electrically connected to the p-side bus bar part 21p1. The p-side finger portion 21p3 extends to the x2 side from the tip end portion on the x2 side of the p-side bus bar portion 21p1. The p-side bus bar portion 21p1 is offset from one side (x1 side) in the x direction of the back surface 10a, and the p-side finger portion 21p3 extends to the other side (x2 side). The p-side finger portion 21p3 has a portion adjacent to the n-side bus bar portion 21n1 in the y direction. Specifically, in the present embodiment, substantially the entire p-side finger portion 21p3 is adjacent to the n-side bus bar portion 21n1 in the y direction. The p-side finger portion 21p3 is located closer to the end side of the back surface 10a than the n-side bus bar portion 21n1 in the y direction.

  The n-side bus bar portion 21n1 has a linear shape extending along the x direction. The n-side bus bar portion 21n1 is provided with its area shifted to the other side (x2 side) in the x direction of the back surface 10a. The n-side bus bar portion 21n1 and the p-side bus bar portion 21p1 are arranged along the x direction. Specifically, the n-side bus bar portion 21n1 and the p-side bus bar portion 21p1 are arranged along the side 10a1 extending in the x direction. The width of the n-side bus bar portion 21n1 along the y direction is smaller than the width of the p-side bus bar portion 21p1 along the y direction. The n-side bus bar portion 21n1 and the p-side bus bar portion 21p1 each include a portion arranged linearly along the x direction.

  Each of the plurality of n-side finger portions 21n2 extends from the n-side bus bar portion 21n1. The plurality of n-side finger portions 21n2 are interleaved with the plurality of p-side finger portions 21p2. The plurality of n-side finger portions 21n2 include a base end portion 21n21, a connection portion 21n22, and a tip end portion 21n23. Specifically, in this embodiment, all n-side finger portions 21n2 have a base end portion 21n21, a connection portion 21n22, and a tip end portion 21n23. The n-side finger portion 21n2 is connected to the n-side bus bar portion 21n1 at the base end portion 21n21. The base end 21n21 extends along the y direction. The connection portion 21n22 connects the base end portion 21n21 and the distal end portion 21n23. The connection part 21n22 includes a bent part or a curved part. Specifically, in the present embodiment, the connection portion 21n22 includes a bent portion. The tip portion 21n23 extends along the y direction. The tip portion 21n23 faces the p-side bus bar portion 21p1 in the y direction. That is, the plurality of n-side electrodes 21n include U-shaped finger portions.

  The plurality of n-side finger portions 21n2 include a relatively long n-side finger portion and a relatively short n-side finger portion. The relatively long n-side finger portion is thinner than the relatively short n-side finger portion. Specifically, in the present embodiment, among the plurality of n-side finger portions 21n2, the n-side finger portion positioned on the outer side is longer and thinner, and the n-side finger portion positioned on the inner side is shorter and thicker.

  A rectangular pad portion 21n3 is provided at the tip end portion on the x2 side of the n-side bus bar portion 21n1. The width along the y direction of the pad portion 21n3 is larger than the width along the y direction of the portion other than the pad portion 21n3 of the n-side bus bar portion 21n1. In the present embodiment, the n-side electrode 21 is electrically connected to the wiring material at the pad portion 21n3.

  FIG. 4 is a schematic plan view of the solar cell string 2 in the first embodiment. In the solar cell string 2, the plurality of solar cells 1 are arranged along the x direction so that the p-side bus bar portion 21p1 and the n-side bus bar portion 21n1 of the adjacent solar cells 1 are adjacent in the x direction. . The p-side bus bar portion 21p1 and the n-side bus bar portion 21n1 of the adjacent solar cells 1 are electrically connected by the wiring material 31. The wiring member 31 is connected by an adhesive layer (not shown) so as to include the tip end portion on the x1 side of the p-side bus bar portion 21p1 and the tip end portion on the x2 side of the n-side bus bar portion 21n1. In FIG. 4, the wiring member 31 is connected to the tip end portion on the x1 side of the p-side bus bar portion 21p1 and the pad portion 21n3 provided at the tip end portion on the x2 side of the n-side bus bar portion 21n1.

  By the way, carriers such as holes and electrons generated in the substrate 11a must move in the substrate 11a before being collected by the electrodes 21n and 21p. However, when the carrier moves, loss due to carrier recombination is accompanied. For this reason, the longer the movement distance of the carrier in the substrate 11a, the more disappearance occurs due to the recombination of carriers. When the disappearance of the carrier occurs, the photoelectric conversion efficiency of the solar cell is lowered accordingly. In particular, the greater the recombination of minority carriers (in this embodiment, holes), the greater the photoelectric conversion efficiency of the solar cell.

  Here, the bus bar portions 21p1, 21n1 are thicker than the finger portions 21p2, 21n2. For this reason, the carriers generated in the portions located below the bus bar portions 21p1 and 21n1 of the substrate 11a are generated by the electrodes 21p and 21n rather than the carriers generated in the portions located below the finger portions 21p2 and 21n2. Must travel long distances before being collected. Therefore, the longer the bus bar portion is, and the larger the occupied area of the bus bar portion on the back surface, the easier the carrier disappears.

  Here, in the present embodiment, the n-side bus bar portion 21n1 and the p-side bus bar portion 21p1 extending in the x direction are arranged along the x direction. For this reason, for example, the p-side bus bar portions 21p1 and n on the back surface 10a are arranged more than when the p-side bus bar portion is arranged along one side of the back surface and the n-side bus bar portion is arranged along the other side facing the one side. The occupation ratio of the side bus bar portion 21n1 can be reduced. Therefore, disappearance due to carrier recombination can be suppressed. Therefore, improved photoelectric conversion efficiency can be realized.

  In particular, in the present embodiment, each of the plurality of p-side finger portions 21p2 and the plurality of n-side finger portions 21n2 has connection portions 21p22 and 21n22 including bent portions, and includes finger portions that are U-shaped. . For this reason, for example, the average length of the plurality of p-side finger portions 21p2 and the average length of the plurality of n-side finger portions 21n2 are larger than when the n-side bus bar portion and the p-side bus bar portion are arranged along the y direction. Can be long. Therefore, the average value of the area per finger part 21p2, 21n2 can be increased. Therefore, the number of finger portions 21p2 and 21n2 can be reduced. Here, it is necessary to lengthen the bus bar portion as the number of finger portions to be connected increases. Therefore, in the present embodiment in which the number of finger portions 21p2 and 21n2 can be reduced, the length of the bus bar portions 21p1 and 21n1 can be further shortened. Therefore, the occupation ratio of the p-side bus bar portion 21p1 and the n-side bus bar portion 21n1 on the back surface 10a can be further reduced. Therefore, more improved photoelectric conversion efficiency can be realized.

  Furthermore, in the present embodiment, the p-side electrode 21p that collects holes that are minority carriers is a finger portion 21p3 that is adjacent to the n-side busbar portion 21n1 of the n-side electrode 21n that collects electrons that are majority carriers in the y direction. Have For this reason, the distance between the part located below the y2 side part of the n side bus-bar part 21n1 among the board | substrates 11a and the p side electrode 21p can be shortened. Therefore, minority carriers (holes) generated in a portion of the substrate 11a located below the y2 side portion of the n-side bus bar portion 21n1 can be efficiently collected in the finger portion 21p3. Therefore, further improved photoelectric conversion efficiency can be realized.

  In the present embodiment, as described above, the n-side bus bar portion 21n1 and the p-side bus bar portion 21p1 are arranged along the x direction. For this reason, as shown in FIG. 4, adjacent solar cells 1 can be easily connected by a short and thin wiring material 31. That is, the adhesion area between the wiring member 31 and the solar cell 1 can be reduced. Moreover, the length along the x direction of the part adhering to the wiring material 31 of the solar cell 1 can be shortened. Therefore, the size of the constrained portion of the solar cell 1 by the wiring material 31 can be reduced. Therefore, for example, even when the temperature of the solar cell module 3 changes and a difference in thermal expansion coefficient occurs between the wiring member 31 and the solar cell 1, the solar cell 1 is hardly warped. In addition, the wiring material 31 is difficult to peel off from the solar cell 1. Therefore, the solar cell module 3 having improved reliability can be realized.

  In the present embodiment, the finger portions 21p2 and 21n2 include a relatively long finger portion and a relatively short finger portion. And a relatively long finger part is thinner than a relatively short finger part. Specifically, in the present embodiment, of the finger parts 21p2 and 21n2, the finger part located on the outer side is longer and thinner, and the finger part located on the inner side is shorter and thicker. For this reason, the difference of the area of a relatively long finger part and the area of a relatively short finger part can be made small. Therefore, for example, when the p-side electrode 21p and the n-side electrode 21n are formed by plating, the difference between the thickness of the relatively long finger portion and the thickness of the relatively short finger portion can be reduced. That is, the p-side electrode 21p and the n-side electrode 21n with small thickness unevenness can be formed by plating.

  Hereinafter, other examples of preferred embodiments of the present invention will be described. In the following description, members having substantially the same functions as those of the first embodiment are referred to by the same reference numerals, and description thereof is omitted.

  In the following second and third embodiments, FIGS. 1 and 4 are referred to in common with the first embodiment.

(Second Embodiment)
FIG. 5 is a schematic plan view of the solar cell in the second embodiment.

  In the first embodiment, the finger portions 21p2 and 21n2 include a relatively long finger portion and a relatively short finger portion, and the relatively long finger portion is a relatively short finger. An example thinner than the above has been described. However, the present invention is not limited to this configuration.

  In the present embodiment, the relatively long finger portion is thicker than the relatively short finger portion. Specifically, in the present embodiment, of the finger portions 21p2 and 21n2, the finger portions located on the outer side are longer and thicker, and the finger portions located on the inner side are shorter and thinner. Thus, the resistance loss in the long finger part can be reduced by increasing the thickness of the long finger part in which many carriers are collected. Therefore, further improved photoelectric conversion efficiency can be realized.

(Third embodiment)
FIG. 6 is a schematic plan view of a solar cell in the third embodiment.

  In the first embodiment, the example in which the p-side bus bar portion 21p1 and the n-side bus bar portion 21n1 are arranged along the side 10a1 has been described. On the other hand, in the present embodiment, the p-side bus bar portion 21p1 and the n-side bus bar portion 21n1 are arranged along the x direction at the central portion in the y direction of the back surface 10a. The plurality of p-side bus bar portions 21p1 include a finger portion whose base end portion extends from the p-side bus bar portion 21p1 to the y1 side and a finger portion whose base end portion extends from the p-side bus bar portion 21p1 to the y2 side. ing. That is, the p-side finger portion 21p2 extends from the p-side bus bar portion 21p1 to both sides in the y direction.

  The plurality of n-side bus bar portions 21n1 include a finger portion whose base end portion extends from the n-side bus bar portion 21n1 to the y1 side, and a finger portion whose base end portion extends from the n-side bus bar portion 21n1 to the y2 side. . That is, the n-side finger portion 21n2 extends from the n-side bus bar portion 21n1 to both sides in the y direction.

  By doing in this way, while maintaining the length of bus bar part 21p1, 21n1 shorter than 1st Embodiment where finger part 21p2, 21n2 is connected only to the y1 side of bus bar part 21p1, 21n1, finger part The number of 21p2 and 21n2 can be increased. As a result, the length of the finger portions 21p2 and 21n2 can be shortened, and the resistance loss can be reduced. Therefore, further improved photoelectric conversion efficiency can be realized.

  In the present embodiment, finger portions 21p3 are arranged in the recesses 21n11 provided in the n-side bus bar portion 21n1.

(Fourth embodiment)
FIG. 7 is a schematic cross-sectional view of a solar cell in the fourth embodiment.

  In the said 1st Embodiment, the solar cell board | substrate 10 demonstrated the example provided with the board | substrate 11a which consists of semiconductors, and the semiconductor layers 11p and 11n. However, the present invention is not limited to this configuration.

  In this embodiment, the solar cell substrate 10 has one conductivity type, and a p-type dopant diffusion region 10P in which a p-type dopant is diffused and an n-type dopant diffusion region 10N in which an n-type dopant is diffused are provided on the back surface side. The substrate 11a is formed. In the present embodiment, the p-type surface 10ap is constituted by the surface of the p-type dopant diffusion region 10P. The n-type surface 10an is constituted by the surface of the n-type dopant diffusion region 10N.

  Even in such a configuration, the same effects as those of the above-described embodiment can be obtained.

  The present invention includes various embodiments not described herein. For example, in the first and second embodiments described above, the example in which the widths of the relatively long finger portions and the relatively short finger portions are different has been described, but the present invention is not limited to this. The present invention includes a case where the widths of the relatively long finger portions and the relatively short finger portions are approximately the same.

  Further, in the third embodiment, the p-side bus bar portion and the n-side bus bar portion are described as an example in which one set is arranged along the x direction at the center portion in the y direction on the back surface. A plurality of sets of p-side bus bar portions and n-side bus bar portions may be arranged along the x direction. In this case, if at least one or more sets of p-side bus bar portions and n-side bus bar portions are provided in the central portion other than the end portions in the y-direction on the back surface, a set of some bus bars in the y-direction. It may be at the end.

  As described above, the present invention includes various embodiments not described herein. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

DESCRIPTION OF SYMBOLS 1 ... Solar cell 3 ... Solar cell module 10 ... Solar cell substrate 10a ... Back surface 10a1 ... Side 10an ... N-type surface 10ap ... P-type surface 21n ... N-side electrode 21n1 ... N-side busbar part 21n2 ... N-side finger part 21n22, 21p22 ... connection part 21p ... p-side electrode 21p1 ... p-side bus bar part 21p2 ... p-side finger part 31 ... wiring material

Claims (19)

A solar cell substrate including an n-type surface and a p-type surface on one principal surface;
An n-side electrode disposed on the n-type surface;
A p-side electrode disposed on the p-type surface;
With
The p-side electrode has a p-side bus bar portion extending along the first direction, and a plurality of p-side finger portions extending from the p-side bus bar portion,
The n-side electrode includes an n-side bus bar portion extending along the first direction, and a plurality of n-side finger portions extending from the n-side bus bar portion and interleaved with the plurality of p-side finger portions. Have
The n-side bus bar portion and the p-side bus bar portion are solar cells arranged along the first direction. The solar cell substrate has a rectangular shape,
The solar cell according to claim 1, wherein the first direction is a direction in which one side of the one main surface extends.   The n-side bus bar portion is arranged with an offset area on one side in the first direction, and the p-side bus bar portion is arranged with an offset area on the other side in the first direction. The solar cell according to claim 1 or 2.   4. The solar cell according to claim 1, wherein each of the n-side bus bar portion and the p-side bus bar portion includes a portion arranged linearly along the first direction.   The area of one bus bar part for collecting minority carriers out of the n-side bus bar part and the p-side bus bar part is larger than the area of the other bus bar part for collecting majority carriers. The solar cell described.   6. The solar cell according to claim 1, wherein each of the plurality of p-side finger portions and the plurality of n-side finger portions includes a finger portion having a bent portion or a curved portion. Each of the plurality of p-side finger portions and the plurality of n-side finger portions is
A base end portion extending vertically from the p-side or n-side busbar portion;
The bent portion or the curved portion;
A distal end portion connected to the base end portion by the bent portion or the curved portion and facing the n-side or p-side busbar portion;
The solar cell according to claim 6, comprising a finger portion having   Each of the said p side finger part and the said n side finger part is a solar cell as described in any one of Claims 1-7 containing a U-shaped finger part.   At least one of the plurality of p-side finger portions and the plurality of n-side finger portions includes a relatively long finger portion and a relatively short finger portion, and the relatively long finger The solar cell according to any one of claims 1 to 8, wherein the portion is thicker than the relatively short finger portion.   At least one of the plurality of p-side finger portions and the plurality of n-side finger portions includes a relatively long finger portion and a relatively short finger portion, and the relatively long finger The solar cell according to any one of claims 1 to 8, wherein the portion is thinner than the relatively short finger portion.   Of the p-side electrode and the n-side electrode, an electrode on the side that collects minority carriers is a bus bar portion of the electrode on the side that collects majority carriers in a second direction perpendicular to the first direction. The solar cell as described in any one of Claims 1-10 which has an adjacent part.   The solar cell according to any one of claims 2 to 11, wherein the p-side bus bar portion and the n-side bus bar portion are arranged along one side of the one main surface. The plurality of p-side finger portions are
A finger portion having a base end portion extending from the p-side bus bar portion to one side in a second direction perpendicular to the first direction;
A base portion extending from the p-side busbar portion to the other side in the second direction;
Including
The plurality of n-side finger portions are
A base portion extending from the n-side busbar portion to one side in the second direction;
A base portion extending from the n-side busbar portion to the other side in the second direction;
The solar cell as described in any one of Claims 1-12 containing this.   14. The solar cell according to claim 13, comprising the p-side bus bar portion and the n-side bus bar portion arranged in a central portion in the second direction of the one main surface.   The solar cell according to any one of claims 1 to 14, wherein a substantially entire surface or an entire surface of the other main surface facing the one main surface of the solar cell substrate is a light receiving surface. A solar cell module comprising a plurality of solar cells and a wiring material electrically connecting the plurality of solar cells,
The solar cell is
A solar cell substrate including an n-type surface and a p-type surface on one principal surface;
An n-side electrode disposed on the n-type surface;
A p-side electrode disposed on the p-type surface;
Have
The p-side electrode has a p-side bus bar portion extending along the first direction, and a plurality of p-side finger portions extending from the p-side bus bar portion,
The n-side electrode includes an n-side bus bar portion extending along the first direction, and a plurality of n-side finger portions extending from the n-side bus bar portion and interleaved with the plurality of p-side finger portions. Have
The n-side bus bar portion and the p-side bus bar portion are solar cell modules arranged along the first direction. The solar cell substrate has a rectangular shape,
The solar cell module according to claim 16, wherein the first direction is a direction in which one side of the one main surface extends. The plurality of solar cells are arranged along the first direction so that the p-side bus bar portion and the n-side bus bar portion of adjacent solar cells are adjacent to each other,
The solar cell module according to claim 16 or 17, wherein the wiring member electrically connects the p-side bus bar portion and the n-side bus bar portion of the adjacent solar cells.   The solar cell module according to claim 18, wherein the wiring member is bonded to a part of the p-side bus bar part and a part of the n-side bus bar part in the first direction.

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