Back contact solar cell and fabrication method thereof

Abstract

The present invention discloses a back contact solar cell. The back contact solar cell includes a semiconductor substrate having a front surface and a rear surface; and a first conductive type semiconductor region having a first conductive type and a second conductive type semiconductor region having a second conductive type, the first conductive type semiconductor region and the second conductive type semiconductor region being disposed with an interval on the rear surface of the semiconductor substrate. In addition, the rear surface of the semiconductor substrate has a texturing structure at the interval between the first conductive type semiconductor region and the second conductive type semiconductor region.

What is claimed is: 
     
         1 . A back contact solar cell, comprising:
 a semiconductor substrate having a front surface and a rear surface; and   a first conductive type semiconductor region having a first conductive type and a second conductive type semiconductor region having a second conductive type, the first conductive type semiconductor region and the second conductive type semiconductor region being disposed with an interval on the rear surface of the semiconductor substrate,   wherein the rear surface of the semiconductor substrate has a texturing structure at the interval between the first conductive type semiconductor region and the second conductive type semiconductor region.   
     
     
         2 . The back contact solar cell according to  claim 1 , wherein the rear surface of the semiconductor substrate further has a portion having a flat surface. 
     
     
         3 . The back contact solar cell according to  claim 2 , further comprising a first electrode in contact with the first conductive type semiconductor region at a first contact and a second electrode in contact with the second conductive type semiconductor region at a second contact, wherein the flat surface is between the first contact and the texturing structure, the second contact and the texturing structure, or both. 
     
     
         4 . The hack contact solar cell according to  claim 3 , wherein a width of a portion of the first electrode is greater than a width of the first conductive type semiconductor region, or a width of a portion of the second electrode is greater than a width of the second conductive type semiconductor region. 
     
     
         5 . The back contact solar cell according to  claim 1 , wherein the rear surface of the semiconductor substrate has the texturing structure locally to correspond only to the interval between the first conductive type semiconductor region and the second conductive type semiconductor region. 
     
     
         6 . The back contact solar cell according to  claim 1 , wherein the texturing structure is not formed on at portions of the rear surface of the semiconductor substrate corresponding to the first conductive type semiconductor region and the second conductive type semiconductor region. 
     
     
         7 . The back contact solar cell according to  claim 1 , wherein a surface roughness of the rear surface of the semiconductor substrate corresponding to the first conductive type semiconductor region and the second conductive type semiconductor region is smaller than a surface roughness of the rear surface of the semiconductor substrate corresponding to the interval between the first conductive type semiconductor region and the second conductive type semiconductor region. 
     
     
         8 . The back contact solar cell according to  claim 1 , further comprising:
 a passivation layer formed at least on the rear surface of the semiconductor substrate at the interval between the first conductive type semiconductor region and the second conductive type semiconductor region.   
     
     
         9 . The back contact solar cell according to  claim 1 , further comprising a passivation layer interposed between the first conductive type semiconductor region and the second conductive type semiconductor region. 
     
     
         10 . The back contact solar cell according to  claim 8 , wherein the passivation layer formed on the rear surface of the semiconductor substrate at the interval between the first conductive type semiconductor region and the second conductive type semiconductor region has a corresponding texturing structure to the texturing structure of the semiconductor substrate. 
     
     
         11 . The back contact solar cell according to  claim 8 , wherein the passivation layer comprises an oxide layer. 
     
     
         12 . The back contact solar cell according to  claim 11 , wherein the passivation layer comprises a silicon oxide layer. 
     
     
         13 . The back contact solar cell according to  claim 1 , wherein the front surface of the semiconductor substrate has a front texturing structure. 
     
     
         14 . The back contact solar cell according to  claim 13 , wherein the front texturing structure is entirely formed on the front surface of the semiconductor. 
     
     
         15 . The back contact solar cell according to  claim 13 , wherein an area of the front texturing structure on the front surface of the semiconductor substrate is larger than an area of the texturing structure on the rear surface of the semiconductor. 
     
     
         16 . The back contact solar cell according to  claim 1 , further comprising:
 a front passivation layer formed on the front surface of the semiconductor substrate.   
     
     
         17 . The back contact solar cell according to  claim 16 , further comprising:
 an anti-reflection coating formed on the front passivation layer.   
     
     
         18 . The back contact solar cell according to  claim 17 , wherein the front passivation layer comprises a silicon oxide layer, and
 the anti-reflection coating comprises a silicon nitride layer.   
     
     
         19 . The back contact solar cell according to  claim 17 , wherein the front passivation layer is entirely formed on the front surface of the semiconductor, and
 the anti-reflection coating is entirely formed on the front passivation layer.   
     
     
         20 . The back contact solar cell according to  claim 17 , wherein the front surface of the semiconductor substrate has a front texturing structure, and
 at least one of the front passivation layer and the anti-reflection coating have a texturing structure corresponding to the front texturing structure.   
     
     
         21 . The back contact solar cell according to  claim 1 , further comprising:
 a first electrode electrically connected to the first conductive type semiconductor region; and   a second electrode electrically connected to the second conductive type semiconductor region.   
     
     
         22 . The back contact solar cell according to  claim 1 , wherein the first conductive type semiconductor region comprises a plurality of first conductive type semiconductor regions,
 the second conductive type semiconductor region comprises a plurality of second conductive type semiconductor regions, and   the plurality of first conductive type semiconductor regions and the plurality of second conductive type semiconductor regions are alternatively formed.