Solar cell and manufacturing method thereof

Abstract

A solar cell includes; a substrate; a first electrode disposed on the substrate, and including a first groove formed therein, a semiconductor layer disposed on the first electrode, and including a second groove formed therein, and a second electrode disposed on the semiconductor layer and connected to the first electrode via the second groove, wherein a third groove passing through the first electrode, the semiconductor layer, and the second electrode is formed in a first region, a fourth groove passing through only the semiconductor layer and the second electrode is formed in a second region, and the first region and the second region are alternately disposed along a direction of extension of the third groove.

What is claimed is: 
     
         1 . A solar cell comprising:
 a substrate;   a first electrode disposed on the substrate, and including a first groove formed therein;   a semiconductor layer disposed on the first electrode, and including a second groove formed therein; and   a second electrode disposed on the semiconductor layer and connected to the first electrode via the second groove,   wherein a third groove passing through the first electrode, the semiconductor layer, and the second electrode is formed in a first region,   a fourth groove passing through the semiconductor layer and the second electrode and extending to a boundary of the first electrode is formed in a second region, and   the first region and the second region are alternately disposed along a direction of extension of the third groove.   
     
     
         2 . The solar cell of  claim 1 , wherein the third groove is formed by irradiating the first electrode, the semiconductor layer and the second electrode with a laser through a mask. 
     
     
         3 . The solar cell of  claim 2 , wherein the laser has a wavelength corresponding to an infrared range. 
     
     
         4 . The solar cell of  claim 3 , wherein the fourth groove is formed at a region overlapping the mask. 
     
     
         5 . The solar cell of  claim 1 , wherein the third groove is formed by irradiating the first electrode, the semiconductor layer and the second electrode with a first laser, and the fourth groove is formed by irradiating the second electrode and the semiconductor layer with a second laser having a different wavelength than the first laser. 
     
     
         6 . The solar cell of  claim 1 , wherein the first electrode is made of at least one of SnO2 and ZnO:B. 
     
     
         7 . The solar cell of  claim 6 , wherein the first electrode includes SnO2, and the wavelength of a laser used when forming the third groove is in a range of about 1060 nm to about 1064 nm. 
     
     
         8 . The solar cell of  claim 1 , wherein a width of the third groove is larger than a width of the fourth groove. 
     
     
         9 . The solar cell of  claim 1 , wherein the first groove is formed by irradiating the first electrode with a laser and the third groove is formed by irradiation of the first electrode, the semiconductor layer and the second electrode with the same laser, and the first groove and the third groove are formed by the laser having the same wavelength. 
     
     
         10 . The solar cell of  claim 1 , wherein the semiconductor layer includes a P-type semiconductor layer, an I layer, and a N-type semiconductor layer sequentially deposited on the first electrode.