JP2008235795A - Solar battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solar battery wherein collection efficiency of photo-generated carriers is improved. <P>SOLUTION: The solar battery 10 includes a conductive electrode 32 which connects a finger electrode 30 that are not connected to a bus bar electrode 31 from among the finger electrodes 30, to the bus bar electrode 31. The finger electrodes 30 are formed side by side in a predetermined direction on a light receiving surface. The bus bar electrode 31 is formed, in a direction almost orthogonal to the predetermined direction on the light receiving surface. The light receiving surface has a first side (base), substantially parallel to the bus bar electrode 31 and a second side (oblique side) connected to the first side. The width in the predetermined direction of the light receiving surface gets narrower, toward a point X where the first side and the second side are connected. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a solar cell.

  Solar cells directly convert clean and inexhaustible sunlight into electricity. Therefore, solar cells are expected as a new energy source.

  The output per solar cell is about several watts. Therefore, when a solar cell is used as a power source for a house or a building, a solar cell module in which a plurality of small area solar cells are electrically connected in series or in parallel is used.

  A solar cell used in a solar cell module is formed by processing a circular semiconductor substrate into a predetermined shape. Here, in order to increase the light receiving area of the solar cell module and improve the utilization efficiency of the circular semiconductor substrate, after processing the circular solar cell into a regular hexagon, it is divided into two by the line connecting the opposite vertices It is known to use a trapezoidal solar cell obtained in the above for a solar cell module (for example, Patent Document 1).

  Here, on the light receiving surface of the solar cell, a finger electrode that collects photogenerated carriers (holes and electrons) generated inside the solar cell, and a bus bar electrode that collects the photogenerated carriers collected by the finger electrode, Is formed.

FIG. 1 shows a general formation pattern of finger electrodes 2 and bus bar electrodes 3 formed on the light receiving surface of a trapezoidal solar cell 1. In order to collect photogenerated carriers from the finger electrodes 2 in a well-balanced manner, the bus bar electrode 3 is arranged in parallel to the lower base in the vicinity of the center of the upper and lower trapezoidal shapes.
JP-A-9-148601

  However, according to the general formation pattern of the finger electrode 2 and the bus bar electrode 3 as shown in FIG. 1, there is an ineffective region α where the finger electrode 2 is not formed near the point X where the lower base of the trapezoid shape and the hypotenuse are connected. Exists. Therefore, there is a problem that the photogenerated carriers cannot be efficiently collected in the invalid region α, and the current collection efficiency of the solar cell 1 is reduced.

  Therefore, the present invention has been made in view of the above-described problems, and an object thereof is to provide a solar cell with improved collection efficiency of photogenerated carriers.

  The solar cell according to the first aspect of the present invention includes a photoelectric conversion unit that generates a photogenerated carrier by light incident from a light receiving surface, a plurality of finger electrodes that collect the photogenerated carrier from the photoelectric conversion unit, A bus bar electrode that collects the photogenerated carriers from the finger electrode, a finger electrode that is not connected to the bus bar electrode among the finger electrodes, and a conductive electrode that connects the bus bar electrode, the finger electrode, The light receiving surface is formed side by side in a predetermined direction, the bus bar electrode is formed on the light receiving surface in a direction substantially perpendicular to the predetermined direction, and the light receiving surface is substantially parallel to the bus bar electrode. One side and a second side connected to the first side, and the width of the light receiving surface in the predetermined direction is such that the first side and the second side are connected to each other. The point is that it is narrowing.

  According to the solar cell according to the first aspect of the present invention, the first side and the second side are connected to the vertical line extending from the point extending the bus bar electrode and intersecting the second side to the first side. The finger electrodes formed in this region, that is, finger electrodes that are not directly connected to the bus bar electrodes can be electrically connected to the bus bar electrodes by the conductive electrodes. Therefore, photogenerated carriers can be efficiently collected from the finger electrodes formed in the region.

  In the first aspect of the present invention, the conductive electrode is preferably formed along the second side from the bus bar electrode toward the first side.

  A second feature of the present invention relates to the first feature of the present invention, and includes another bus bar electrode that collects the photogenerated carriers from the finger electrode, and the other bus bar electrode is formed on the light receiving surface. The gist is that the second bus bar electrode is formed in a direction substantially perpendicular to a predetermined direction, and the other bus bar electrode is formed closer to the first side than the bus bar electrode.

  According to the solar cell according to the second aspect of the present invention, the finger electrodes not directly connected to the bus bar electrode (first bus bar electrode) among the finger electrodes directly connected to the other bus bar electrode (second bus bar electrode). The photogenerated carriers collected by are transported not only to other bus bar electrodes but also to the bus bar electrodes via the conductive electrodes. In particular, photogenerated carriers collected at a position far from the other bus bar electrode 31b are collected to the bus bar electrode. That is, the photogenerated carriers collected by the finger electrodes not directly connected to the bus bar electrode among the finger electrodes directly connected to the other bus bar electrodes can be efficiently collected by the bus bar electrode and the other bus bar electrodes.

  In the second feature of the present invention, it is preferable that the bus bar electrode and the other bus bar electrode are formed at a distance of approximately half or more of the height of the light receiving surface with the first side as a base.

  2nd characteristic of this invention WHEREIN: It is preferable to provide the other conductive electrode which connects the said finger electrode which is not connected with the said other bus-bar electrode, and the said other bus-bar electrode.

  In the second aspect of the present invention, the other conductive electrode is preferably formed along the second side from the other bus bar electrode toward the first side.

  ADVANTAGE OF THE INVENTION According to this invention, the solar cell which improved the collection efficiency of photogenerated carrier can be provided.

<< First Embodiment >>
Next, a first embodiment of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic and ratios of dimensions and the like are different from actual ones. Accordingly, specific dimensions and the like should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

<Schematic configuration of solar cell module>
A schematic configuration of the solar cell module will be described with reference to the drawings.

FIG. 2 is a cross-sectional view of the solar cell module 100 according to the present embodiment. In FIG. 2, the upper side of the drawing is the light receiving surface side of the solar cell module 100, and the lower side of the drawing is the back side of the solar cell module 100.

  The solar cell module 100 according to this embodiment includes a plurality of solar cells 10, a tab 40, a sealing material 50, a surface protection material 60, and a back surface protection material 70.

  The solar cell 10 includes a photoelectric conversion unit 20, a plurality of finger electrodes 30, a bus bar electrode 31, and a conductive electrode 32 (not shown). The configuration of the solar cell 10 will be described later.

  The tab 40 is a conductive material such as copper formed into a thin plate shape or a twisted wire shape. The tab 40 solders the bus bar electrode 31 provided on the light incident surface of one solar cell 10 and the bus bar electrode 31 provided on the back surface of another solar cell 10 adjacent to the one solar cell 10. Connected through. Thereby, one solar cell 10 and another solar cell 10 adjacent to the one solar cell 10 are electrically connected in series or in parallel.

  The sealing material 50 seals the plurality of solar cells 10 electrically connected to each other in series or in parallel by the tab 40. As the sealing material 50, a light-transmitting resin such as EVA, EEA, PVB, silicon, urethane, acrylic, or epoxy can be used.

  The surface protective material 60 is disposed on the light incident surface side of the sealing material 50. As the surface protective material 60, glass having translucency and water shielding property, translucent plastic, or the like can be used.

  The back surface protective material 70 is disposed on the back surface side of the sealing material 50. As the back surface protective material 70, a resin film such as PET (Polyethylene Terephthalate), a laminated film having a structure in which an Al foil is sandwiched between resin films, or the like can be used.

  The solar cell module 100 is configured as described above. Note that an Al frame (not shown) can be attached around the solar cell module 100 in order to increase the strength of the module and firmly attach it to the gantry.

<Configuration of Solar Cell 10>
Next, the structure of the solar cell 10 is demonstrated using drawing. FIG. 3 is a plan view of the solar cell 10 according to the present embodiment.

  The solar cell 10 includes a photoelectric conversion unit 20, a plurality of finger electrodes 30, a bus bar electrode 31, and a conductive electrode 32.

  The photoelectric conversion unit 20 generates a photogenerated carrier by light incident from the light receiving surface. The photogenerated carrier refers to holes and electrons that are generated when light is absorbed by the photoelectric conversion unit 20. The photoelectric conversion unit 20 has a semiconductor junction such as a semiconductor pn junction or a semiconductor pin junction as a basic structure. The photoelectric conversion unit 20 includes a semiconductor material such as a crystalline semiconductor material such as single crystal Si or polycrystalline Si, a thin film semiconductor material such as an amorphous Si alloy or CuInSe, or a compound semiconductor material such as GaAs or InP, or a dye. An organic material such as a sensitizing type can be used.

  Here, as shown in FIG. 3, the light receiving surface of the photoelectric conversion unit 20 has a substantially trapezoidal shape in plan view. Specifically, as shown in FIG. 3, the light receiving surface of the photoelectric conversion unit 20 has an upper base A (about 30 mm), a lower base B (about 80 mm), a hypotenuse C (about 100 mm) and a side D (about 80 mm). have. The lower base B and the hypotenuse C are connected at a point X. The width of the light receiving surface of the photoelectric conversion unit 20 is narrowed toward the point X in the direction orthogonal to the lower base B.

  The finger electrode 30 is an electrode that collects photogenerated carriers from the photoelectric conversion unit 20. As shown in FIG. 3, a plurality of finger electrodes 30 are formed in a line at predetermined intervals in a predetermined direction over almost the entire light receiving surface of the photoelectric conversion unit 20. In the present embodiment, the predetermined direction in which the finger electrode 30 is formed is a direction substantially orthogonal to the lower base B.

  The bus bar electrode 31 is an electrode that collects photogenerated carriers from the plurality of finger electrodes 30. As shown in FIG. 3, the bus bar electrode 31 is formed so as to be orthogonal to the plurality of finger electrodes 30. In other words, the bus bar electrode 31 is formed in a direction substantially orthogonal to a predetermined direction in which the finger electrodes 30 are formed. Accordingly, the bus bar electrode 31 is formed substantially parallel to the upper base A and the lower base B. Further, the bus bar electrode 31 is formed in the vicinity of the middle between the upper base A and the lower base B in order to collect the photogenerated carriers from the finger electrodes 30 in a well-balanced manner. Accordingly, the bus bar electrodes 31 do not intersect with some of the finger electrodes 30 formed on the light receiving surface. Specifically, as shown in FIG. 3, the finger electrode 30 formed in the region β on the side of the point X from the perpendicular extending from the point Y that extends the bus bar electrode 31 and intersects the hypotenuse C to the lower base B is The bus bar electrode 31 is not directly connected. The bus bar electrode 31 is formed larger than the finger electrode 30 in both width and height in order to carry carriers collected from the plurality of finger electrodes 30.

  The conductive electrode 32 is an electrode for carrying the photogenerated carriers collected from the finger electrode 30 formed in the region β to the bus bar electrode 31. Therefore, the conductive electrode 32 is formed to have an intermediate width and height between the finger electrode 30 and the bus bar electrode 31. The conductive electrode 32 connects the finger electrode 30 formed in the region β and the bus bar electrode 31. The conductive electrode 32 is formed along the oblique side C from the bus bar electrode 31 toward the lower base B.

  Here, as the finger electrode 30, the bus bar electrode 31, and the conductive electrode 32, a sintered conductive paste or a thermosetting conductive paste can be used. The sintered conductive paste is a so-called ceramic paste, for example, a silver paste containing silver powder, glass frit, an organic vehicle, and an organic solvent. The thermosetting conductive paste is a resin paste using a thermosetting resin as a binder, for example, a silver paste in which silver particles are dispersed in an epoxy thermosetting resin solution. In particular, when the photoelectric conversion unit 20 includes an amorphous semiconductor layer, the finger electrode 30, the bus bar electrode 31, and the conductive electrode 32 are thermally cured in a temperature range in which thermal damage to the semiconductor layer in the photoelectric conversion unit 20 is small. It is desirable that the conductive paste be formed.

  Although not shown, the electrodes (finger electrodes 30, bus bar electrodes 31, and conductive electrodes 32) on the back surface of the photoelectric conversion unit 20 may be formed in the same pattern as the light receiving surface side of the photoelectric conversion unit 20. Further, it may be formed so as to cover the entire back surface. The present invention does not limit the shape of the electrode provided on the back surface of the photoelectric conversion unit 20. In the present embodiment, as an example, it is assumed that the electrodes (finger electrodes 30, bus bar electrodes 31, and conductive electrodes 32) are formed in the same pattern as the light receiving surface on the back surface of the photoelectric conversion unit 20.

  Next, the photoelectric conversion part 20 which makes an example of the structure of the solar cell 10 which concerns on this embodiment is demonstrated. 4 is a cross-sectional view taken along the line II ′ of FIG.

  Specifically, the photoelectric conversion unit 20 includes an n-type single crystal silicon substrate 20d, an i-type amorphous silicon layer 20c, a p-type amorphous silicon layer 20b, a transparent conductive film 20a, and an i-type amorphous silicon layer 20e. The n-type amorphous silicon layer 20f and the transparent conductive film 20g are provided. An i-type amorphous silicon layer 20c, a p-type amorphous silicon layer 20b, and a transparent conductive film 20a are sequentially stacked on the light-receiving surface side of the n-type single crystal silicon substrate 20d. An i-type amorphous silicon layer 20e, an n-type amorphous silicon layer 20f, and a transparent conductive film 20g are sequentially stacked on the back side of the n-type single crystal silicon substrate 20d. The finger electrode 30, the bus bar electrode 31, and the conductive electrode 32 (not shown) are formed on the light receiving surface of the ITO film 20a and the back surface of the ITO film 20g. In such a photoelectric conversion unit 20, between the pn junction formed by the n-type single crystal silicon substrate 20d and the p-type amorphous silicon layer 20b, and between the n-type single crystal silicon substrate 20d and the n-type amorphous silicon Between the layer 20f, i-type amorphous silicon layers 20c and 20e having extremely thin thickness are respectively inserted.

  The solar cell module 100 having the solar cell 10 having such a configuration is called a HIT solar cell module.

  As shown in FIG. 2, the solar cell 10 having the above configuration is electrically connected in series or in parallel with other solar cells 10 by a wiring tab 40.

<Method for manufacturing solar cell module>
A method for manufacturing the solar cell module 100 according to the present embodiment will be described. In the following description, please refer to FIGS.

  First, the circular n-type single crystal silicon substrate 20d is anisotropically etched with an alkaline aqueous solution to form fine irregularities on the surface. Further, the surface of the n-type single crystal silicon substrate 20d is washed to remove impurities.

  Next, an i-type amorphous silicon layer 20c and a p-type amorphous silicon layer 20b are sequentially stacked on the light-receiving surface of the n-type single crystal silicon substrate 20d by using a vapor phase growth method such as an RF plasma CVD method. To do. Similarly, an i-type amorphous silicon layer 20e and an n-type amorphous silicon layer 20f are sequentially stacked on the back surface of the n-type single crystal silicon substrate 20d.

  Next, an ITO film 20a is formed on the light receiving surface of the p-type amorphous silicon layer 20b by using a magnetron sputtering method. Similarly, an ITO film 20g is formed on the back surface of the n-type amorphous silicon layer 20f.

  Next, a silver paste is arranged in a predetermined pattern on the light receiving surface of the ITO film 20a by using a printing method such as a screen printing method or an offset printing method. Similarly, a silver paste is arranged in a predetermined pattern on the back surface of the ITO film 20g. Thereby, the finger electrode 30, the bus bar electrode 31, and the conductive electrode 32 are integrally formed on the photoelectric conversion unit 20. In this embodiment, the predetermined pattern in which the finger electrode 30, the bus bar electrode 31, and the conductive electrode 32 are formed is as shown in FIG. The finger electrode 30 may be formed to have a width of about 0.1 mm, the bus bar electrode 31 may have a width of about 0.7 mm, and the conductive electrode 32 may have a width of about 0.3 mm. It is not limited to this.

  Thus, the circular solar cell 10 is produced.

  Next, a split groove is formed on the back surface of the circular solar cell 10 using a YAG laser device, and the solar cell 10 is cut along the split groove. In this embodiment, the solar cell 10 is divided into four equal parts by cleaving the photoelectric conversion unit 20 along the dividing grooves. Thereby, the substantially trapezoidal solar cell 10 is created.

  Next, the tab 40 is soldered onto the bus bar electrode 31. Thereby, the one solar cell 10 and the other solar cell 10 adjacent to the one solar cell 10 are electrically connected in series or in parallel.

  Next, a plurality of solar cells 10, EVA (sealing material 50) sheets, and back surface protection material 70 connected to each other by the EVA (sealing material 50) sheet and tab 40 on the glass substrate (surface protection material 60). A laminated body is formed by sequentially laminating. The back surface protective material 70 has a three-layer structure of PET / aluminum / PET.

  Next, the solar cell module 100 is manufactured by heat-pressing the laminated body in a vacuum atmosphere. Note that a terminal box, an Al frame, or the like can be attached to the solar cell module 100.

<Action and effect>
In the solar cell 10 according to the present embodiment, the plurality of finger electrodes 30 are formed in a direction orthogonal to the lower bottom B on the light receiving surface, and the bus bar electrode 31 is substantially orthogonal to a predetermined direction in which the finger electrodes 30 are formed. The conductive electrode 32 is formed to connect the bus bar electrode 31 to the finger electrode 30 that is not directly connected to the bus bar electrode 31 among the finger electrodes 30. The width of the light receiving surface of the photoelectric conversion unit 20 is narrowed toward the point X where the lower base B and the hypotenuse C are connected in the direction in which the finger electrode 30 is formed.

  Accordingly, the bus bar electrode 31 is extended and directly connected to the finger electrode 30 formed in the region β on the point X side from the perpendicular line extending from the point Y intersecting the hypotenuse C to the lower base B, that is, the bus bar electrode 31. The non-finger electrode 30 can be electrically connected to the bus bar electrode 31 by the conductive electrode 32. Therefore, photogenerated carriers can be efficiently collected from the finger electrode 30 formed in the region β. As a result, the current collection efficiency of the solar cell 10 is improved, and the solar cell characteristics can be improved.

<< Second Embodiment >>
Next, a second embodiment of the present invention will be described with reference to FIGS. The configuration of the solar cell module according to this embodiment is the same as that of the first embodiment.

<Configuration of Solar Cell 10>
First, the configuration of the solar cell 10 according to the present embodiment will be described mainly focusing on the differences from the first embodiment. FIG. 5 is a plan view of the solar cell 10 according to the present embodiment.

  As shown in FIG. 5, the solar cell 10 according to the present embodiment includes two bus bar electrodes 31 (first bus bar electrode 31a and second bus bar electrode 31b) and two conductive electrodes 32 (first conductive electrode). Electrode 32a and second conductive electrode 32b).

  The first bus bar electrode 31 a and the second bus bar electrode 31 b are electrodes that collect photogenerated carriers from the plurality of finger electrodes 30. As shown in FIG. 3, the first bus bar electrode 31 a and the second bus bar electrode 31 b are formed to be orthogonal to the plurality of finger electrodes 30. In other words, the first bus bar electrode 31a and the second bus bar electrode 31b are formed in a direction substantially orthogonal to a predetermined direction in which the finger electrodes 30 are formed. Accordingly, the first bus bar electrode 31a and the second bus bar electrode 31b are formed substantially parallel to the upper base A and the lower base B.

  Further, in order to collect the photogenerated carriers from the finger electrode 30 in a balanced manner, the first bus bar electrode 31a is separated from the lower base B by approximately three-fourths of the height h of the light receiving surface with the lower base B as the base. The second bus bar electrode 31b is formed so as to be separated from the lower base B by about a quarter of the height h of the light receiving surface with the lower base B as the base. That is, the second bus bar electrode 31b is formed away from the first bus bar electrode 31a by approximately one half of the height h of the light receiving surface with the bottom B as the base. Accordingly, the first bus bar electrode 31a and the second bus bar electrode 31b do not intersect with some of the finger electrodes 30 among the finger electrodes 30 formed on the light receiving surface.

  Specifically, as shown in FIG. 5, the finger electrode formed in the region γ on the point X side from the perpendicular line extending from the point M intersecting the hypotenuse C to the lower base B by extending the first bus bar electrode 31 a. 30 is not directly connected to the first bus bar electrode 31a. Similarly, the finger electrode 30 formed in the region δ on the side of the point X from the perpendicular extending from the point N intersecting the oblique side C to the lower base B by extending the second bus bar electrode 31b is directly connected to the second bus bar electrode 31b. Not connected to.

  The first conductive electrode 32a and the second conductive electrode 32b are electrodes for carrying photogenerated carriers collected from the finger electrodes 30 formed in the regions γ and δ to the first bus bar electrode 31a and the second bus bar electrode 31b. is there. The first conductive electrode 32a connects the first bus bar electrode 31a, the finger electrode 30 formed in the region γ (excluding the region δ), and the second bus bar electrode 31b. The first conductive electrode 32a is formed along the oblique side C from the first bus bar electrode 31a toward the lower bottom B. The second conductive electrode 32b connects the second bus bar electrode 31b and the finger electrode 30 formed in the region δ. The second conductive electrode 32b is formed along the oblique side C from the second bus bar electrode 31b toward the lower bottom B.

  About another structure, it is the same as that of 1st Embodiment. FIG. 6 is a cross-sectional view of FIG. The configuration shown in FIG. 6 is the same as that shown in FIG. 4 except that two bus bar electrodes (first bus bar electrode 31a and second bus bar electrode 31b) are formed.

  Further, the manufacturing method of the solar cell module 100 is the same as that in the first embodiment except that the silver bus paste is used to form two bus bar electrodes and two conductive electrodes in the pattern shown in FIG. is there.

<Action and effect>
In the solar cell 10 according to the present embodiment, the plurality of finger electrodes 30 are formed in a direction orthogonal to the lower base B on the light receiving surface, and the first bus bar electrode 31a has a predetermined direction in which the finger electrodes 30 are formed. The first conductive electrode 32a is formed in a substantially orthogonal direction, and the first conductive electrode 32a includes a finger electrode 30 that is not directly connected to the first bus bar electrode 31a among the finger electrodes 30 that are directly connected to the second bus bar electrode 31b, and the first bus bar. It is formed so as to connect to the electrode 31a. In addition, the width of the light receiving surface of the photoelectric conversion unit 20 is narrowed toward the point X where the lower base B and the hypotenuse C are connected in the direction in which the finger electrode 30 is formed.

  Therefore, the photogenerated carriers collected by the finger electrode 30 not directly connected to the first bus bar electrode 31a among the finger electrodes 30 directly connected to the second bus bar electrode 31b by the first conductive electrode 32a are second It is carried not only to the bus bar electrode 31b but also to the first bus bar electrode 31a. In particular, photogenerated carriers collected at a position far from the second bus bar electrode 31b are collected to the first bus bar electrode 31a. That is, the photogenerated carriers collected by the finger electrode 30 not directly connected to the first bus bar electrode 31a among the finger electrodes 30 directly connected to the second bus bar electrode 31b are converted into the first bus bar electrode 31a and the second bus bar electrode. It can be efficiently collected by 31b.

  The second conductive electrode 32b is formed so as to connect the finger electrode 30 of the finger electrode 30 that is not directly connected to the second bus bar electrode 31b and the second bus bar electrode 31b.

  Therefore, the finger electrode 30 that is not directly connected to the second bus bar electrode 31b can be electrically connected to the second bus bar electrode 31b by the second conductive electrode 32b. Therefore, photogenerated carriers can be efficiently collected from the finger electrode 30 formed in the region δ.

  As a result, the current collection efficiency of the solar cell 10 is improved, and the characteristics of the solar cell 10 can be improved.

<Other embodiments>
Although the present invention has been described according to the above-described embodiments, it should not be understood that the descriptions and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  For example, in the above embodiment, the size of the light receiving surface of the photoelectric conversion unit 20 is such that the length of the upper base A is about 30 mm, the length of the lower base B is about 80 mm, and the length of the hypotenuse C is viewed in plan view. Although the length of 100 mm and the side D is about 80 mm, the size of the light receiving surface is not limited.

  Moreover, in the said embodiment, although the light-receiving surface of the photoelectric conversion part 20 was formed in trapezoid shape in planar view, the width | variety of the light-receiving surface in the direction in which the finger electrode 30 is formed is a lower side and a hypotenuse. The light-receiving surface may be formed in an isosceles trapezoidal shape, a sector shape, an elliptical shape, or other polygonal shapes.

  In the solar cell module 100 according to the above embodiment, the pattern in which the finger electrodes 30 and the bus bar electrodes 31 intersect in a comb shape has been described. However, the patterns need not be orthogonal to each other and may intersect obliquely. .

  In the first embodiment, one bus bar electrode is used. In the second embodiment, two bus bar electrodes are used. However, three or more bus bar electrodes may be formed.

  Moreover, in the said 2nd Embodiment, although the solar cell 10 was set as the structure provided with the 2nd electroconductive electrode 32b, even if it is a structure which is not provided with the 2nd electroconductive electrode 32b, it is directly connected with the 2nd bus-bar electrode 31b. Among the finger electrodes 30, the photogenerated carriers collected by the finger electrodes 30 that are not directly connected to the first bus bar electrode 31a can be efficiently collected by the first bus bar electrode 31a and the second bus bar electrode 31b.

  In the second embodiment, the first conductive electrode 32a is connected to the first bus bar electrode 31a and the second bus bar electrode 31b. However, as shown in FIG. May not touch. In this case, it is preferable that the first conductive electrode 32a is formed up to approximately one-half of the height h of the light receiving surface with the bottom B as the base.

  In the second embodiment, the second bus bar electrode 31b is formed away from the first bus bar electrode 31a by approximately one half of the height h of the light receiving surface with the lower base B as the base. However, if the height h is approximately one half or more apart, the finger electrode 30 that is not directly connected to the first bus bar electrode 31a among the finger electrodes 30 that are directly connected to the second bus bar electrode 31b. The effect that the collected photogenerated carriers can be efficiently collected by the first bus bar electrode 31a and the second bus bar electrode 31b is remarkably exhibited.

  In the above embodiment, the conductive electrode 32 is formed along the oblique side C from the bus bar electrode 31 toward the lower base B. However, the conductive electrode 32 is directly connected to the bus bar electrode 31 to which the conductive electrode 32 is connected. As long as it is connected to the finger electrode 30 that has not been formed, the formation pattern of the conductive electrode 32 is not limited.

  As described above, the present invention naturally 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.

It is a top view of the conventional solar cell 1. FIG. It is sectional drawing of the solar cell module 100 which concerns on 1st Embodiment. It is a top view of the solar cell 10 which concerns on 1st Embodiment. FIG. 4 is a cross-sectional view taken along the line II in FIG. 3. It is a top view of the solar cell 10 which concerns on 2nd Embodiment. FIG. 6 is a cross-sectional view of FIG. It is a top view of the solar cell 10 which concerns on other embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Solar cell, 2 ... Finger electrode, 3 ... Bus-bar electrode, 10 ... Solar cell, 20 ... Photoelectric conversion part, 20a ... Transparent electrically conductive film, 20b ... p-type amorphous silicon layer, 20c ... i-type amorphous silicon 20d ... n-type single crystal silicon substrate, 20e ... i-type amorphous silicon layer, 20f ... n-type amorphous silicon layer, 20g ... transparent conductive film, 30 ... finger electrode, 31 ... busbar electrode, 31a ... first 1 bus bar electrode, 31b ... second bus bar electrode, 32 ... conductive electrode, 32a ... first conductive electrode, 32b ... second conductive electrode, 40 ... tab, 50 ... sealing material, 60 ... surface protective material, 70 ... back surface protective material, 100 ... solar cell module, A ... upper base, B ... lower base, C ... oblique side, D ... side, α ... region, β ... region, γ ... region, δ ... region

Claims (6)

A photoelectric conversion unit that generates photogenerated carriers by light incident from the light receiving surface;
A plurality of finger electrodes for collecting the photogenerated carriers from the photoelectric conversion unit;
A bus bar electrode for collecting the photogenerated carriers from the finger electrodes;
A finger electrode that is not connected to the bus bar electrode among the finger electrodes, and a conductive electrode that connects the bus bar electrode;
The finger electrodes are formed side by side in a predetermined direction on the light receiving surface,
The bus bar electrode is formed on the light receiving surface in a direction substantially orthogonal to the predetermined direction,
The light receiving surface has a first side substantially parallel to the bus bar electrode, and a second side connected to the first side,
The width of the light receiving surface in the predetermined direction is narrowed toward a point where the first side and the second side are connected.   2. The solar cell according to claim 1, wherein the conductive electrode is formed along the second side from the bus bar electrode toward the first side. Comprising another bus bar electrode for collecting the photogenerated carriers from the finger electrode;
The other bus bar electrode is formed in a direction substantially perpendicular to the predetermined direction on the light receiving surface,
3. The solar cell according to claim 1, wherein the other bus bar electrode is formed closer to the first side than the bus bar electrode. 4.   4. The solar cell according to claim 3, wherein the bus bar electrode and the other bus bar electrode are formed at a distance of approximately half or more of the height of the light receiving surface with the first side as a base. 5.   5. The solar cell according to claim 3, further comprising another conductive electrode that connects the finger electrode not connected to the other bus bar electrode and the other bus bar electrode. 6. The solar cell according to claim 5, wherein the another conductive electrode is formed along the second side from the other bus bar electrode toward the first side.

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