Patent Publication Number: US-2011048491-A1

Title: Solar-cell module and solar cell

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority based on 35 USC 119 from prior Japanese Patent Application No. P2009-196144 filed on Aug. 26, 2009, entitled “SOLAR-CELL MODULE AND SOLAR CELL”, the entire contents of which are incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a solar-cell module including plural solar cells that are electrically connected to one another with a wiring material and also relates to a solar cell. 
     2. Description of Related Art 
     Solar cells are capable of converting sunlight energy, which is clean and can be inexhaustibly supplied, directly into electric energy, and are therefore expected to be a new energy source. 
     A solar cell includes a photoelectric conversion body configured to generate carriers by receiving sunlight or the like, plural finger electrodes configured to collect the carriers generated by the photoelectric conversion body, busbar electrodes connected to the plural finger electrodes, and the like. Generally, the finger electrodes and the busbar electrodes are provided on both a front surface (light-receiving surface) and a rear surface of the photoelectric conversion body. 
     In addition, because a single solar-cell has an output of approximately several watts, a solar-cell module that enhances the output by connecting plural solar cells with a tab (wiring material) is used. The tab is bonded to a top of the busbar electrode with a resin adhesive. 
     It has been proposed to form such a solar-cell module by use of a solar cell that has a busbar electrode with a non-linear shape such as a zigzag shape to more securely connect the busbar electrode and the tab to each other (see, for example, Japanese Patent No. 4294048 ( FIG. 6 )). In such a solar cell, the busbar electrode, without being made wider, can be connected to the tab more securely and can achieve improved conductivity in comparison to an ordinary, linearly-shaped busbar electrode bonded to a tab with solder. 
     However, if busbar electrodes with non-linear shapes, such as zigzag shapes, are provided both on a front surface (light-receiving surface) of a photoelectric conversion body and on a rear surface thereof, and if the positions of the busbar electrodes printed, by screen printing or the like, on the front surface and the rear surface of the photoelectric conversion body do not coincide with each other, the following problem takes place. 
     Specifically, areas where the busbar electrodes exist are pressurized when the busbar electrodes and the tabs are bonded to one another. In this process, if the position of the busbar electrode on the front-surface side and the position of the busbar electrode on the rear-surface side are offset a little from each other, an unsupportable shear stress acts on the photoelectric conversion body, and damages such as cracks are likely to occur in the photoelectric conversion body. Consequently, a problem of lowering the yields of the solar cells occurs. 
     SUMMARY OF THE INVENTION 
     An aspect of the invention provides a solar-cell module that comprises: a plurality of solar cells electrically connected each other by wiring materials, each solar cell comprising: a photoelectric conversion body including a first surface irradiated with light and a second surface located on the opposite side to the first surface, the photoelectric conversion body configured to generate carriers by the irradiation of light; a plurality of finger electrodes provided on both the first surface and the second surface, and configured to collect the carriers generated by the photoelectric conversion body; and a busbar electrode provided on each of the first surface and the second surface so as to intersect the plurality of finger electrodes, and having a non-linear shape, wherein each of the busbar electrode provided on the first surface and the busbar electrode formed on the second surface includes at least two markers for alignment of positions. 
     It is preferable that each of the markers is provided on a center line that passes through a center of the corresponding busbar electrode in a direction orthogonal to a direction in which the busbar electrode extends. 
     It is preferable that in a plan view of the photoelectric conversion body, each of the markers provided on the first surface overlaps the corresponding marker provided on the second surface. 
     It is preferable that each of the markers has a rectangular shape, and each of the markers has a long side extending in a direction in which each of the plurality of finger electrodes extends. 
     It is preferable that the markers provided on the first surface are different in shape from the markers provided on the second surface. 
     It is preferable that the wiring materials are bonded to tops of the busbar electrodes with a resin adhesive. 
     Another aspect of the invention provides a solar cell that comprises a photoelectric conversion body including a first surface irradiated with light and a second surface located on the opposite side to the first surface, the photoelectric conversion body configured to generate carriers by the irradiation of light; a plurality of finger electrodes provided on both the first surface and the second surface, and configured to collect the carriers generated by the photoelectric conversion body; and a busbar electrode provided on each of the first surface and the second surface so as to intersect the plurality of finger electrodes, and having a non-linear shape, wherein each of the busbar electrodes provided on the first surface and the busbar electrode formed on the second surface includes at least two markers for alignment of positions. 
     Still another aspect of the invention provides a method of solar cell that comprises: forming a photoelectric conversion body including a first surface irradiated with light and a second surface located on the opposite side to the first surface, the photoelectric conversion body configured to generate carriers by the irradiation of light; forming a plurality of finger electrodes provided on both the first surface and the second surface, and configured to collect the carriers generated by the photoelectric conversion body; and forming a busbar electrode provided on each of the first surface and the second surface so as to intersect the plurality of finger electrodes, and having a non-linear shape, wherein each of the busbar electrodes provided on the first surface and the busbar electrode formed on the second surface includes at least two markers for alignment of positions. 
    
    
     
       BRIEF DESCRIPTION CF THE DRAWINGS 
         FIG. 1  is a schematic perspective view of a solar-cell module according to an embodiment. 
         FIG. 2  is a plan view of light-receiving surface S 1  of solar cell  100 A according to the embodiment. 
         FIG. 3  is a plan view of rear surface S 2  of solar cell  100 A according to the embodiment. 
         FIG. 4  is a sectional view of a part of solar cell  100 A taken along line F 4 -F 4  shown in  FIG. 2 . 
         FIG. 5  is an enlarged plan view of area A 1  shown in  FIG. 2 . 
         FIG. 6  is a flowchart illustrating a method of aligning busbar electrodes employing markers  200 A to  200 D according to the embodiment. 
         FIG. 7  is a schematic view of printer  300  used to print electrodes and markers according to the embodiment. 
         FIGS. 8A and 8B  are views respectively illustrating a front surface and a rear surface of transparent member  110 T according to the embodiment. 
         FIG. 9  is a view illustrating an example of the positional offset of marker  200 B and marker  200 C according to the embodiment. 
         FIGS. 10A and 10B  are views illustrating busbar electrodes according to modified examples. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     Embodiments of the invention are explained with referring to drawings. In the respective drawings referenced herein, the same constituents are designated by the same reference numerals and duplicate explanation concerning the same constituents is basically omitted. All of the drawings are provided to illustrate the respective examples only. No dimensional proportions in the drawings shall impose a restriction on the embodiments. For this reason, specific dimensions and the like should be interpreted with the following descriptions taken into consideration. In addition, the drawings include parts whose dimensional relationship and ratios are different from one drawing to another. 
     Prepositions, such as “on”, “over” and “above” may be defined with respect to a surface, for example a layer surface, regardless of that surface&#39;s orientation in space. The preposition “above” may be used in the specification and claims even if a layer is in contact with another layer. The preposition “on” may be used in the specification and claims when a layer is not in contact with another layer, for example, when there is an intervening layer between them. 
     (1) General Configuration of Solar-Cell Module 
       FIG. 1  is a schematic perspective view of a solar-cell module. As  FIG. 1  shows, solar-cell module  10  includes plural solar cells (solar cells  100 A to  100 C). Note that the number of the solar cells included in solar-cell module  10  is not limited to the number shown in  FIG. 1 . 
     Each of tabs  20  electrically connects plural solar cells to one another. In the embodiment, tabs  20  are wiring materials. In the embodiment, each tab  20  is connected both to light-receiving surface S 1  of solar cell  100 A and to rear surface S 2  of solar-cell  100 B, which is a different solar cell that is adjacent to solar cell  100 A, solar cells  100 A and  100 B being included in solar-cell module  10 . 
     Tabs  20  are preferably made of a material with low electrical resistance, such as a thin plate-shaped copper, silver, gold, tin, nickel, aluminum, an alloy of these, or the like. Note that the front surface of each tab  20  may be plated with a conductive material such as a lead-free solder (e.g. SnAg 3.0 Cu 0.5 ). 
     Solar-cells  100 A to  100 C may have the same structure, and therefore the structure of solar cell  100 A is described below. 
     Solar cell  100 A includes photoelectric conversion body  110 , finger electrodes  120 , and busbar electrodes  130 . 
     Photoelectric conversion body  110  includes light-receiving surface S 1  and rear surface S 2 . Light-receiving surface S 1  (first surface) is a surface that is irradiated with light, such as sunlight. Rear surface S 2  (second surface) is located on the opposite side to light-receiving surface S 1 . Photoelectric conversion body  110  generates carriers by irradiation of light onto light-receiving surface S 1 . Here, the carriers refer to the holes and electrons generated when light, such as sunlight, is absorbed by photoelectric conversion body  110 . 
     Each finger electrode  120  collects the carriers generated by photoelectric conversion body  110 . Plural finger electrodes  120  are provided on light-receiving surface S 1 . 
     Each busbar electrode  130  is electrically connected to plural finger electrodes  120  that are provided on light-receiving surface S 1 . In this embodiment, the width of each busbar electrode  130  is substantially the same as that of the finger electrodes  120  provided on light-receiving surface S 1 , and two busbar electrodes  130  are provided in parallel to each other on light-receiving surface S 1 . Each busbar electrode  130  is provided on light-receiving surface S 1  so as to intersect plural finger electrodes  120 . 
     Note that, though not shown in  FIG. 1 , rear surface S 2  is provided with electrodes that are similar to both finger electrodes  120  and busbar electrode  130  (i.e., finger electrodes  220  and busbar electrodes  230  (see  FIG. 3 )). 
     Tabs  20  are wider than finger electrodes  120 ,  220 , busbar electrode  130 , and  230 . Tabs  20  are bonded to the tops of busbar electrodes  130 , light-receiving surface S 1  of photoelectric conversion body  110 , and to the tops of busbar electrodes  230 , rear surface S 2  of photoelectric conversion body  110  with a resin adhesive (not illustrated). In addition, solar-cell module  10  is provided with a light-receiving surface member, a rear surface member, and a sealing material to seal solar cells  100 A to  100 C that are connected to each other with tabs  20 , but the configurations of and materials of these additional members are similar to those in the conventional case, so that no description of these members is given. 
     (2) Configuration of Solar Cell 
     Subsequently, the configuration of solar cell  100 A is described. Specifically, description is given of the overall configuration of solar cell  100 A, and of the positions and shapes of busbar electrodes. 
     (2.1) Overall Configuration 
       FIG. 2  is a plan view of light-receiving surface S 1  of solar cell  100 A.  FIG. 3  is a plan view of rear surface S 2  of solar cell  100 A.  FIG. 4  is a sectional view of a part of solar cell  100 A taken along line F 4 -F 4  shown in  FIG. 2 . Note that the hatching of photoelectric conversion body  110  is omitted from  FIG. 4 . 
     As has been described earlier, photoelectric conversion body  110  generates carriers by receiving light. For example, photoelectric conversion body  110  includes an n type region and a p type region inside of photoelectric conversion body  110 . A semiconductor junction is formed at the interface of the n type region and the p type region. Photoelectric conversion body  110  may be formed with a semiconductor substrate made, for example, of a crystalline semiconductor material, such as mono crystal S 1  and poly crystal S 1 , of a compound semiconductor material, such as GaAs and InP, or the like. Note that photoelectric conversion body  110  may have a so-called HIT (Hetero-junction with Intrinsic Thin layer) structure, which is a structure to improve the properties at the hetero-junction interface by sandwiching an intrinsic amorphous silicon layer between mono crystal silicon and amorphous silicon. 
     Light-receiving surface S 1  of solar cell  100 A is provided with finger electrodes  120  and busbar electrodes  130  that are connected to finger electrodes  120 . Likewise, rear surface S 2  of solar cell  100 A is provided with finger electrodes  220  and busbar electrodes  230  that are connected to finger electrodes  220 . Each busbar electrode  130  ( 230 ) extends in an orthogonal direction (in direction. D 1 ) that is orthogonal to finger electrodes  120  ( 220 ). 
     Finger electrodes  120  and  220  as well as busbar electrodes  130  and  230  may be formed by printing conductive paste  30  (not illustrated in  FIG. 2  to  FIG. 4 ; see  FIG. 7 ) by screen printing or the like method. 
     As  FIG. 2  and  FIG. 3  show, each finger electrode  120  has a linear shape. In contrast, none of busbar electrodes  130  and busbar electrodes  230  has a linear shape. Specifically, each of busbar electrodes  130  and busbar electrodes  230  has a zigzag shape with a certain amplitude in the direction in which each finger electrode  120  ( 220 ) extends (in direction D 2  shown in  FIGS. 2 and 3 ). 
     In the embodiment, each busbar electrode  130  and each busbar electrode  230  have identical shapes. To put it differently, solar  11   100 A includes busbar electrodes of identical shapes provided both on light-receiving surface S 1  and on rear surface S 2 . In addition, busbar electrodes  230  are provided on rear surface  82  at the same positions where busbar electrodes  130  are formed on light-receiving surface S 1  with photoelectric conversion body  110  located in between. To put it differently, in a plan view of photoelectric conversion body  110 , the positions where busbar electrodes  130  are provided overlap the positions where busbar electrodes  230  are provided. 
     In addition, each of busbar electrodes  130  and busbar electrodes  230  is covered at least partially with tab  20 . The resin adhesive to be used when busbar electrodes  130  ( 230 ) and tabs  20  are bonded together is preferably one that is hardened at a temperature lower than or equal to the melting point (approximately 200° C.) of the lead-free solder. Some of the adhesives to be used as the resin adhesive are thermo-setting resin adhesives such as an acrylic resin and highly-flexible polyurethane-based resin, as well as two-liquid reaction adhesives such as ones made by mixing a hardening agent with any of an epoxy resin, acrylic resin, and urethane resin. In addition, in this embodiment, the resin adhesive contains plural conducting particles. Nickel, nickel coated with gold, or the like may be used as such conducting particles. 
     Each busbar electrode  130  includes markers  200 A and  200 B. Likewise, each busbar electrode  230  includes markers  200 C and  200 D. To put it differently, in this embodiment, each of busbar electrodes  130  and busbar electrodes  230  includes two markers for alignment. 
     Markers  200 A to  200 D can be used to align busbar electrodes  130  provided on light-receiving surface S 1  with busbar electrodes  230  provided on rear surface S 2 . Specifically, markers  200 A to  200 D are used to check whether the positions of busbar electrodes  130  are or are not properly aligned with the positions of busbar electrodes  230  in a plan view of photoelectric conversion body  110 . Note that the specific method of the alignment is described later. 
     Both marker  200 A and marker  200 B are provided on light-receiving surface S 1 . Specifically, marker  200 A and marker  200 B are provided respectively at the two end portions of each busbar electrode  130  in the direction in which busbar electrode  130  extends (in direction D 1  in  FIGS. 2 and 3 ). Likewise, marker  200 C and marker  200 D are provided respectively at the two end portions of each busbar electrode  230  in the direction in which busbar electrode  230  extends (in direction D 1  in  FIGS. 2 and 3 ). 
     Markers  200 A ( 200 B) provided on light-receiving surface S 1  overlap respectively markers  200 D ( 200 C) provided on rear surface S 2  in a plan view of photoelectric conversion body  110 . To put it differently, if light-receiving surface S 1  faces upwards, markers  200 D ( 200 C) are positioned right below their corresponding markers  200 A ( 200 B) with photoelectric conversion body  110  located in between. 
     In addition, in this embodiment, markers  200 A to  200 D are provided at positions covered with tabs  20 . To put it differently, after tabs  20  are bonded to photoelectric conversion body  110 , neither markers  200 A nor markers  200 B (neither markers  200 C nor markers  200 D) are basically exposed from light-receiving surface S 1  (rear surface S 2 ). 
     (2.2) Positions and Shapes of Busbar Electrodes 
       FIG. 5  is an enlarged plan view of area A 1  shown in  FIG. 2 . As  FIG. 5  shows, marker  200 A is provided at an end portion of each busbar electrode  130  in the direction in which busbar electrode  130  extends (in direction D 1  in  FIG. 5 ). To put it differently, each marker  200 A is continuous to the corresponding busbar electrode  130 . In addition, each marker  200 A is provided on center line CL passing on the center of the corresponding busbar electrode  130  in the direction orthogonal to the direction in which each busbar electrode  130  extends (in direction D 2  in  FIG. 5 ). 
     In this embodiment, each marker  200 A has a rectangular shape. To put it differently, each of markers  200 A to  200 D has a shape that is different from each of non-linearly shaped busbar electrodes  130  and  230 . Specifically, each marker  200 A has a rectangular shape, and long side  210  of each marker  200 A extends in the direction in which each finger electrode  120  extends (in direction D 1 ). In addition, each marker  200 A overlaps any of finger electrodes  120 . 
     In this embodiment, each finger electrode  120  has a line width of approximately 0.1 mm. The pitch of finger electrodes  120  is approximately 2.0 mm. In addition, each busbar electrode  130  ( 230 ) has amplitude W B  of approximately 1.6 mm. In addition, the length of long side  210  of each of markers  200 A to  200 D is preferably smaller than amplitude W B . However, to facilitate the alignment, the length of longer side  210  is preferably as large as possible. In addition, to avoid the exposure of markers  200 A to  200 D from light-receiving surface S 1  after the completion of solar-cell module  10 , the length of long side  210  is preferably smaller than the width of each tab  20 . 
     Note that each marker  200 B provided at the opposite end of the corresponding busbar electrode  130  to the corresponding marker  200 A has a similar relative position and a similar shape to those of marker  200 A. In addition, each marker  200 C (see  FIG. 3 ) provided at one end portion of the corresponding busbar electrode  230  is similar to each marker  200 A whereas each marker  200 D (see  FIG. 3 ) provided at the other end portion of the corresponding busbar electrode  230  is similar to each marker  200 B. 
     (3) Method of Aligning Busbar Electrodes 
       FIG. 6  is a flowchart illustrating a method of aligning busbar electrodes using above-described markers  200 A to  200 D. Specifically,  FIG. 6  shows an operational flow to align the positions of busbar electrodes  130  provided on light-receiving surface S 1  with the positions of busbar electrodes  230  provided on rear surface S 2 . 
     As  FIG. 6  shows, at step S 10 , transparent member  110 T (see  FIG. 8 ) with an identical shape to that of photoelectric conversion body  110 , that is, with the same quadrangular shape of the same size as that of photoelectric conversion body  110  is prepared. Transparent member  110 T has certain transparency. Specifically, transparent member  110 T needs to have enough transparency to allow the view from front surface S 1 T side to rear surface S 2 T side of transparent member  110 T. 
     At step S 20 , electrodes and markers are printed on front surface SIT of transparent member  110 T. 
       FIG. 7  is a schematic view of printer  300  to be used to print electrodes and markers. As  FIG. 7  shows, printer  300  includes screen  310 , stage  320 , squeegee  330  and alignment mechanism  340 . 
     Holes  310   a  are formed in screen  310  so as to correspond to the pattern of electrodes and markers. Transparent member  110 T is mounted on stage  320 . Note that in an actual printing process, photoelectric conversion body  110  is mounted on stage  320  in place of transparent member  110 T. Stage  320  provides a function to adjust the position of transparent member  110 T on the plane of screen  310 . 
     Squeegee  330  pushes conductive paste  30  out through holes  310   a  formed in screen  310 . Thus, conductive paste  30  is placed on transparent member  110 T following the pattern of electrodes and markers. 
     Alignment mechanism  340  provides adjustment the position of screen  310  on the plane of transparent member  110 T. 
       FIG. 8A  shows a state where electrodes and markers are formed on front surface SIT of transparent member  110 T. Using printer  300  shown in  FIG. 7 , finger electrodes  120  and busbar electrodes  130  are formed on front surface S 1 T of transparent member  110 T. In addition, markers  200 A and markers  200 B to be used to align busbar electrodes  130  with busbar electrodes  230  are also formed along with finger electrodes  120  and busbar electrodes  130 . 
     Subsequently, as  FIG. 6  shows, at step S 30 , transparent member  110 T is turned upside down to make rear surface S 2 T of transparent member  110 T face upwards. Note that transparent member  110 T is turned upside down in the direction orthogonal to the direction in which the squeegee  330  moves.  FIG. 8B  shows a state where transparent member  110 T with electrodes and markers formed on front surface SIT is turned upside down. 
     At step S 40 , a transparent film is attached to rear surface S 2 T of transparent member  110 T. Transparent film tray be anything that conductive paste  30  can be printed on. 
     At step S 50 , electrodes and markers are printed on rear surface S 2 T of transparent member  110 T. The printing of electrodes and markers on rear surface S 2 T is performed using another printer that is similar to printer  300  shown in  FIG. 7 . Alternatively, if the positions of stage  320  and alignment mechanism  340  can be stored in a memory, the same printer may be used. In addition, the printing of electrodes and markers on rear surface S 2 T is performed using markers  200 A and  200 B formed on front surface SIT as the reference. 
     At step S 60 , on the basis of the positions of markers  200 A and  200 B formed on front surface SIT and the positions of markers  200 C and  200 D formed on rear surface S 2 T, the positional offset of busbar electrodes  130  formed on front surface SIT and busbar electrodes  230  formed on rear surface S 2 T is detected. 
     The positional offset can be detected using a detection system equipped with a camera and the like. Alternatively, the positional offset may be visually detected by an operator if the pitch of the electrodes and the sizes of the markers allow it. 
       FIG. 9  is a view illustrating an example of the positional offset of marker  200 B and marker  200 C. As  FIG. 9  shows, in the state where transparent member  110 T is turned upside down (see  FIG. 8B ), marker  200 E formed on front surface SIT is positioned at the left end portion of transparent member  110 T. If, in this state, electrodes and markers are printed on rear surface S 2 T of transparent member  110 T, marker  200 B completely overlaps marker  200 C unless the positional offset in printing occurs. 
     In contrast, if the positional offset in printing occurs, marker  200 B does not completely overlap marker  200 C as  FIG. 9  shows. In this way, by checking the positions of marker  200 B and marker  200 C printed on transparent member  110 T, whether or not the positional offset is beyond an allowable range. 
     At step S 70 , whether or not the positional offset is beyond an allowable range is determined. If the positional offset is within the allowable range (YES at step S 70 ), the operation is completed. 
     In contrast, if the positional offset is beyond the allowable range (NO at step S 70 ), the transparent film attached to rear surface S 2 T of transparent member  110 T is removed at step S 80 . 
     At step S 90 , the positions of the electrodes and markers printed on rear surface S 2 T are adjusted. Specifically, by adjusting either stage  320  or alignment mechanism  340  of printer  300 , the positions of the electrodes and markers printed on rear surface S 2 T are adjusted. By adjusting the position of stage  320 , the position of transparent member  110 T mounted on stage  320  relative to screen  310  is changed. In contrast, by adjusting the position of screen  310 , the position of screen  310  relative to transparent member  110 T is changed. 
     In the example shown in  FIG. 9 , by adjusting either stage  320  or alignment mechanism  340 , the positions at which the electrodes and markers are printed are moved in the direction indicated by the arrow in  FIG. 9 . 
     Subsequently, the processes of steps S 40  to S 90  are repeated. Specifically, if the positional offset is beyond the allowable range, the printing on rear surface S 2 T is performed again. Note that, needless to say, the operational flow described above can be automated with a system. 
     (4) Advantageous Effects 
     According to above-described solar cell  100 A ( 100 B or  100 C) and the above-described method of aligning busbar electrodes, the positions of busbar electrodes  130  formed on light-receiving surface S 1  can be easily aligned with the positions of busbar electrodes  230  formed on rear surface S 2 . 
     Accordingly, even if the areas where busbar electrodes  130  are arranged are pressurized when busbar electrodes  130  ( 230 ) and tabs  20  are bonded together, no unsupportable shear stress acts on photoelectric conversion body  110  because the positions of busbar electrodes  130  are aligned with the positions of busbar electrodes  230 . Specifically, the stress acting on photoelectric conversion body  110  via busbar electrodes  130  at the time of pressurization is borne by busbar electrodes  230 , so that no unsupportable shear stress acts on photoelectric conversion body  110 . 
     According to this embodiment, occurrence of damages such as cracks in photoelectric conversion body  110  can be reduced and the lowering of yields of solar cells can be reduced. 
     According to this embodiment, each of markers  200 A to  200 D is provided on center line CL of the corresponding busbar electrode (see  FIG. 5 ). Accordingly, the shapes of the markers and of the busbar electrodes can be used for alignment of positions, so that the workability and accuracy of the alignment of positions can be improved. 
     In this embodiment, markers  200 A ( 200 B) formed on light-receiving surface S 1  overlap respectively markers  200 D ( 200 C) formed on rear surface  82  in a plan view of photoelectric conversion body  110 . Accordingly, such a configuration is convenient when the aligning is performed with transparent member  110 ′ turned upside down. 
     In this embodiment, each of markers  200 A to  200 D has a rectangular shape. Specifically, each of markers  200 A to  200 D has a box shape, and long side  210  extends in the direction in which each finger electrode extends (in direction D 2 ). In addition, each of markers  200 A to  200 D overlaps one of finger electrodes. Accordingly, the shapes of the markers and of finger electrodes can be used for alignment of positions, so that the workability and accuracy of the alignment of positions can be improved furthermore. 
     In this embodiment, markers  200 A to  200 D are provided at positions that are covered with tabs  20 . Accordingly, if solar-cell module  10  is completed, none of markers  200 A to  200 D is basically exposed from light-receiving surface  81 , and even if markers  200 A to  200 D are provided, the conversion efficiency of solar cells does not deteriorate. 
     (5) Other Embodiments 
     As described above, the content of the invention is disclosed by means of the embodiment, but the descriptions and the drawings that form a part of this disclosure should not be understood as anything that limits the invention. Those skilled in the art may conceive of various alternative embodiments, examples, and techniques from this disclosure. 
     For example, in the above-described embodiment, markers  200 A to  200 D are provided at positions that are covered with tabs  20 , but markers  200 A to  200 D do not necessarily have to be provided at positions that are covered with tabs  20 . 
     In addition, each of markers  200 A to  200 D may have a circular shape or a triangular shape instead of a rectangular shape. In addition, the positions of and the number of the markers on light-receiving surface S 1  (rear surface S 2 ) are not limited to those in the above-described embodiment. For example, two markers only need to be provided respectively at two positions (e.g., marker  200 A located at the upper left in  FIG. 2  and marker  200 B located at the lower right) on a diagonal line on light-receiving surface S 1  (rear surface S 2 ). Alternatively, if at least two markers are provided on each of light-receiving surface S 1  and rear surface S 2 , the positions thereof do not have to be on a diagonal line. In addition, markers do not have to be continuous to busbar electrodes, and may be provided near but independently of the busbar electrodes. 
     In addition, the shapes of the markers provided on light-receiving surface S 1  may be different from the shapes of the markers provided on rear surface S 2 . For example, each of the markers on light-receiving surface S 1  may have a rectangular shape, whereas each of the markers on rear surface S 2  may have a triangular shape. If the markers have different shapes in this way, the n side and the p side of photoelectric conversion body  110  can be distinguished from each other easily. 
     In the above-described embodiment, each busbar electrode has a zigzag shape, but the invention is applicable to a case where each of busbar electrodes has a non-linear shape such as a wavy shape as busbar electrode 131  shown in  FIG. 10A  or an oblique-line shape as busbar electrodel 32  shown in  FIG. 10B . In addition, the shape of each busbar electrode provided on light-receiving surface S 1  may be partly different a little from the shape of each busbar electrode provided on rear surface S 2 . 
     In the above-described embodiment, the number of finger electrodes  120  provided on light-receiving surface S 1  of solar cell  100 A and the number of finger electrodes  220  provided on rear surface  52  of solar cell  100 A are equal to each other, but may be different from each other. Specifically, the number of finger electrodes  220  may be larger than the number of finger electrodes  120 . 
     In the above-described embodiment, a resin adhesive that contains conducting particles is used, but the resin adhesive does not necessarily have to contain conducting particles. 
     According to the embodiments of the invention, the solar-cell module and the solar cell that can be provided are capable of reducing the lowering of yields caused by the damages on the photoelectric conversion body at the time of the manufacturing of the solar-cell nodule and of the solar cell when busbar electrodes with non-linear shapes such as zigzag shapes are provided.