Patent ID: 8609451
Filing Date: 2013-12-17
Classification: H01L,Y02E,Y02P

Abstract:
1. A method of fabricating a thin epitaxial silicon solar cell comprising: depositing by chemical vapor deposition an epitaxial film of highly doped p-type silicon on a porous silicon layer on a silicon wafer, said highly doped p-type silicon epitaxial film having a resistivity of less than 20 mohm-cm, said highly doped p-type silicon epitaxial film being a back surface field (BSF) layer; depositing by chemical vapor deposition an epitaxial film of p-type silicon on said BSF layer, said p-type silicon epitaxial film being a base layer; exfoliating said BSF layer and said base layer from said silicon wafer; forming an emitter layer at the surface of said base layer; forming front contacts to said emitter layer on the front surface of said thin epitaxial silicon solar cell; and forming back contacts to said BSF layer on the back surface of said thin epitaxial silicon solar cell, said back contacts being patterned to cover less than fifty percent of the back surface of said thin epitaxial silicon solar cell; wherein said thin epitaxial silicon solar cell is less than 200 microns thick.