Solar cell and solar cell panel including the same

Abstract

Disclosed is a solar cell panel including: a semiconductor substrate having a long axis and a short axis that intersect; a first conductivity type region formed on one surface of the semiconductor substrate; a second conductivity type region formed on the other surface of the semiconductor substrate; a first electrode electrically connected to the first conductivity type region; and a second electrode electrically connected to the second conductivity type region. The first electrode includes: a plurality of finger lines positioned in a first direction parallel to the long axis and being parallel to each other; and a plurality of bus bars including a plurality of pad portions positioned in a second direction parallel to the short axis. The plurality of pad portions include a first outer pad and a second outer pad located on opposite ends of the plurality of bus bars in the second direction, respectively.

What is claimed is: 
     
         1 . A solar cell, comprising:
 a semiconductor substrate having a long axis and a short axis that intersect;   a first conductivity type region formed on one surface of the semiconductor substrate;   a second conductivity type region formed on another surface of the semiconductor substrate;   a first electrode electrically connected to the first conductivity type region; and   a second electrode electrically connected to the second conductivity type region,   wherein the first electrode comprises:
 a plurality of finger lines positioned in a first direction parallel to the long axis and being parallel to each other; and 
 a plurality of bus bars including a plurality of pad portions and positioned in a second direction parallel to the short axis, and 
   wherein the plurality of pad portions comprise a first outer pad and a second outer pad located on opposite ends of the plurality of bus bars in the second direction, respectively.   
     
     
         2 . The solar cell of  claim 1 , wherein a ratio of a pitch of the plurality of bus bars in the first direction to a width of the semiconductor substrate in the second direction is 0.35 or less. 
     
     
         3 . The solar cell of  claim 2 , wherein the ratio of the pitch of the plurality of bus bars in the first direction to the width of the semiconductor substrate in the second direction is 0.1 to 0.35. 
     
     
         4 . The solar cell of  claim 1 , wherein a ratio of a width of the semiconductor substrate in the second direction to a length of the semiconductor substrate in the first direction is 0.2 to 0.5. 
     
     
         5 . The solar cell of  claim 1 , wherein a number of the plurality of bus bars is six or more. 
     
     
         6 . The solar cell of  claim 5 , wherein the number of the plurality of bus bars is six to fourteen. 
     
     
         7 . The solar cell of  claim 1 , wherein the first outer pad and the second outer pad are inwardly located on the solar cell than outermost finger lines among the plurality of finger lines in the second direction, respectively. 
     
     
         8 . The solar cell of  claim 1 , wherein the first outer pad and the second outer pad are symmetrically located in the second direction of the solar cell. 
     
     
         9 . The solar cell of  claim 1 , wherein the plurality of pad portions further comprise an inner pad positioned between the first outer pad and the second outer pad, and
 wherein at least one of the plurality of bus bars further comprises a line portion connecting the plurality of pad portions in the second direction.   
     
     
         10 . The solar cell of  claim 1 , wherein an electrode area of the solar cell in which the plurality of finger lines are disposed comprises:
 a first electrode area located between two adjacent bus bars of the plurality of bus bars; and   a second electrode area located between one bus bar of the plurality of bus bars and a short side of the solar cell, and   
       wherein a width of the first electrode area is smaller than a width of the second electrode area. 
     
     
         11 . The solar cell of  claim 1 , further comprising a cut surface and a non-cut surface, and
 wherein a first gap between one of the first conductive type region and the second conductivity type region or one of the first electrode and the second electrode and the cut surface is smaller than a second gap between one of the first conductive type region and the second conductivity type region or one of the first electrode and the second electrode and the non-cut surface.   
     
     
         12 . A solar cell panel, comprising:
 a plurality of solar cells including a first solar cell and a second solar cell; and   a plurality of leads connecting the first solar cell and the second solar cell and having a rounded portion,   wherein each of the plurality of solar cells comprises:
 a semiconductor substrate having a long axis and a short axis that intersect; 
 a first conductivity type region formed on one surface of the semiconductor substrate; 
 a second conductivity type region formed on another surface of the semiconductor substrate; 
 a first electrode electrically connected to the first conductivity type region; and 
 a second electrode electrically connected to the second conductivity type region, 
   wherein the first electrode comprises:
 a plurality of finger lines positioned in a first direction parallel to the long axis and being parallel to each other; and 
 a plurality of bus bars including a plurality of pad portions and positioned in a second direction parallel to the short axis, and 
   wherein the plurality of pad portions comprise a first outer pad and a second outer pad located on opposite ends of the plurality of bus bars in the second direction, respectively,   wherein the plurality of leads extend along the second direction.   
     
     
         13 . The solar cell panel of  claim 12 , wherein a ratio of a pitch of the plurality of bus bars in the first direction to a width of the semiconductor substrate in the second direction is 0.35 or less. 
     
     
         14 . The solar cell panel of  claim 13 , wherein the ratio of the pitch of the plurality of bus bars in the first direction to the width of the semiconductor substrate in the second direction is 0.1 to 0.35. 
     
     
         15 . The solar cell panel of  claim 12 , wherein a ratio of a width of the semiconductor substrate in the second direction to a length of the semiconductor substrate in the first direction is 0.2 to 0.5. 
     
     
         16 . The solar cell panel of  claim 12 , wherein a number of the plurality of bus bars or a number of the plurality of leads is six or more. 
     
     
         17 . The solar cell panel of  claim 16 , wherein the number of the plurality of bus bars or the number of the plurality of leads is six to fourteen. 
     
     
         18 . The solar cell panel of  claim 12 , wherein at least one of the plurality of leads includes a core layer and a solder layer located on an outer surface of the core layer, and
 wherein the at least one of the plurality of leads is fixed to the plurality of pad portions by the solder layer.   
     
     
         19 . The solar cell panel of  claim 18 , wherein a width of the solder layer gradually increases toward the plurality of pad portions at a portion of the solder layer adjacent to the plurality of pad portions. 
     
     
         20 . The solar cell panel of  claim 12 , wherein each of the first solar cell and the second solar cell has first and second long sides formed along the long axis and being parallel to each other, first and second short sides formed along the short axis and being parallel to each other, a first inclined side connecting the first long side and the first short side, and a second inclined side connecting the first long side and the second short side, and
 wherein the first long side of the first solar cell and the first long side of the second solar cell face each other, the first and second inclined sides of the first solar cell and the first and second inclined sides of the second solar cell face each other, or the second long side of the first solar cell and the second long side of the second solar cell face each other.