Method of forming contacts for a back-contact solar cell

Abstract

Methods of forming contacts for solar cells are described. In one embodiment, a method includes forming a silicon layer above a substrate, forming and patterning a solid-state p-type dopant source on the silicon layer, forming an n-type dopant source layer over exposed regions of the silicon layer and over a plurality of regions of the solid-state p-type dopant source, and heating the substrate to provide a plurality of n-type doped silicon regions among a plurality of p-type doped silicon regions.

What is claimed is: 
     
         1 . A solar cell, comprising:
 a dielectric layer formed on a substrate;   a plurality of n-type dopant-containing silicon regions formed between a plurality of p-type dopant-containing silicon regions; and   trenches formed in the plurality of n-type dopant-containing silicon regions and partially in the substrate, wherein the trenches are formed between the plurality of n-type dopant-containing silicon regions and the p-type dopant-containing silicon regions; and   conductive contacts in contact with the plurality of n-type dopant-containing silicon regions and the p-type dopant-containing silicon regions.   
     
     
         2 . The solar cell of  claim 1 , wherein the dielectric layer has a thickness in the range of 5-50 Angstroms. 
     
     
         3 . The solar cell of  claim 1 , wherein the plurality of n-type dopant-containing silicon regions comprise a plurality of n-type doped polysilicon regions with a sheet resistance in the range of 50-300 ohms per square. 
     
     
         4 . The solar cell of  claim 1 , wherein the plurality of p-type dopant-containing silicon regions comprise a plurality of p-type doped polysilicon regions with a sheet resistance in the range of 50-300 ohms per square.