Silicon-containing heterojunction photovoltaic element and device

Abstract

In one embodiment, a method of forming a photovoltaic device is provided which includes providing an absorption layer comprising a silicon-containing semiconductor layer of a first conductivity type and having a top surface and a bottom surface that opposes the top surface. A front contact is formed on the top surface of the absorption layer, and a back contact is formed on the bottom surface of the absorption layer. The forming of the front contact and the back contact can occur in any order. The back contact that is formed comprises at least one back contact semiconductor material layer of the first conductivity type and having a lower band-offset than that of hydrogenated amorphous silicon with crystalline Si and/or a higher activated doping of the first conductivity type than that of the doped hydrogenated amorphous silicon layer.

1 . A method of forming a photovoltaic device comprising:
 providing an absorption layer comprising a silicon-containing semiconductor layer of a first conductivity type and having a top surface and a bottom surface that opposes said top surface;   forming a front contact located on the top surface of the absorption layer; and   forming a back contact located on the bottom surface of the absorption layer, wherein said back contact comprises at least one back contact semiconductor material layer of the first conductivity type and having a lower band-offset than that of hydrogenated amorphous silicon with crystalline silicon, and/or a higher level of activated doping concentration compared to that of doped hydrogenated amorphous Si.   
     
     
         2 . The method of  claim 1 , wherein said providing the absorption layer comprises selecting a p-type single crystalline silicon-containing material. 
     
     
         3 . The method of  claim 1 , wherein said providing the absorption layer comprises selecting an n-type single crystalline silicon-containing material. 
     
     
         4 . The method of  claim 1 , further comprising forming back metal fingers on a bottommost surface of said back contact. 
     
     
         5 . The method of  claim 1 , further comprising forming front metal fingers on an uppermost surface of the front contact. 
     
     
         6 . The method of  claim 4 , wherein said forming said back metal fingers comprises screen printing or application of an etched or electroformed metal pattern. 
     
     
         7 . The method of  claim 5 , wherein said forming said front metal fingers comprises screen printing or application of an etched or electroformed metal pattern. 
     
     
         8 . A method of forming a photovoltaic device comprising:
 providing an absorption layer comprising a silicon-containing semiconductor layer of a first conductivity type and having a top surface and a bottom surface that opposes said top surface;   forming a front contact located on the top surface of the absorption layer, wherein said front contact comprises at least one front contact semiconductor material layer of a second conductivity type and having a lower band-offset than that of hydrogenated amorphous silicon with crystalline silicon, and/or a higher level of activated doping concentration compared to that of doped hydrogenated amorphous Si, and wherein said second conductivity type is opposite the first conductivity type; and   forming a back contact located on the bottom surface of the absorption layer.   
     
     
         9 . The method of  claim 8 , wherein said providing the absorption layer comprises selecting a p-type single crystalline silicon-containing material. 
     
     
         10 . The method of  claim 8 , wherein said providing the absorption layer comprises selecting an n-type single crystalline silicon-containing material. 
     
     
         11 . The method of  claim 8 , further comprising forming back metal fingers on a bottommost surface of said back contact. 
     
     
         12 . The method of  claim 8 , further comprising forming front metal fingers on an uppermost surface of the front contact. 
     
     
         13 . The method of  claim 11 , wherein said forming said back metal fingers comprises screen printing or application of an etched or electroformed metal pattern. 
     
     
         14 . The method of  claim 12 , wherein said forming said front metal fingers comprises screen printing or application of an etched or electroformed metal pattern.