Solar cells having junctions retracted from cleaved edges

Abstract

Methods of fabricating solar cells having junctions retracted from cleaved edges, and the resulting solar cells, are described. In an example, a solar cell includes a substrate having a light-receiving surface, a back surface, and sidewalls. An emitter region is in the substrate at the light-receiving surface of the substrate. The emitter region has sidewalls laterally retracted from the sidewalls of the substrate. A passivation layer is on the sidewalls of the emitter region.

What is claimed is: 
     
         1 . A method of fabricating a solar cell, the method comprising:
 forming an emitter region in a substrate, at a light-receiving surface of the substrate;   forming a trench in the emitter region;   forming a passivation layer on the light-receiving surface of the substrate and in the trench to passivate an emitter edge; and   cleaving the substrate to form a solar cell having sidewalls and an emitter region having sidewalls laterally retracted from the sidewalls of the solar cell.   
     
     
         2 . The method of  claim 1 , wherein cleaving the substrate comprises cleaving through the passivation layer in the trench. 
     
     
         3 . The method of  claim 1 , wherein cleaving substrate comprises cleaving through a portion of the emitter region laterally adjacent the trench. 
     
     
         4 . The method of  claim 1 , wherein the trench is formed using laser ablation. 
     
     
         5 . The method of  claim 1 , wherein the trench is formed using an etch paste delivered by screen print or inkjet.