Three-dimensional thin film semiconductor substrate with through-holes and methods of manufacturing

Abstract

A three-dimensional thin-film semiconductor substrate with selective through-holes is provided. The substrate having an inverted pyramidal structure comprising selectively formed through-holes positioned between the front and back lateral surface planes of the semiconductor substrate to form a partially transparent three-dimensional thin-film semiconductor substrate.

What is claimed is: 
     
         1 . A three-dimensional thin-film solar cell, comprising:
 a plurality of at least two differently sized three-dimensional inverted pyramidal cavities comprising a larger set of three-dimensional inverted pyramidal cavities and a smaller set of three-dimensional inverted pyramidal cavities wherein said larger set of inverted pyramidal cavities and said smaller set of inverted pyramidal cavities are arranged in a staggered pattern on a semiconductor substrate;   a plurality of selectively formed through-holes in said semiconductor substrate with openings between the front and back lateral surface planes of said semiconductor substrate which form a partially transparent three-dimensional thin-film semiconductor substrate,   wherein said semiconductor substrate has an inverted pyramidal structure with a layer thickness in the range of 1 to 60 microns and a substrate peak to peak thickness in the range of approximately 100 to 500 microns;   a sunny side doped emitter region positioned on the top surface of said semiconductor substrate;   a back surface field p-type doped base region positioned on the bottom surface of said semiconductor substrate;   a plurality of emitter metal contacts positioned on base openings of said inverted pyramidal cavities on said semiconductor substrate; and   a plurality of base metal contacts positioned on the bottom surface of said semiconductor substrate at the apex of said inverted pyramidal cavities on said semiconductor substrate.   
     
     
         2 . The three-dimensional thin-film solar cell of  claim 1 , wherein said plurality of selectively formed through-holes in said semiconductor substrate are positioned in said smaller set of three-dimensional inverted pyramidal cavities on said semiconductor substrate. 
     
     
         3 . The three-dimensional thin-film solar cell of  claim 1 , wherein said plurality of selectively formed through-holes in said semiconductor substrate are positioned in said larger set of three-dimensional inverted pyramidal cavities on said semiconductor substrate. 
     
     
         4 . The three-dimensional thin-film solar cell of  claim 1 , wherein said plurality of selectively formed through-holes in said semiconductor substrate are positioned on the top surface areas on said semiconductor substrate. 
     
     
         5 . The three-dimensional thin-film solar cell of  claim 1 , further comprising a front side surface passivation layer positioned on said doped emitter region. 
     
     
         6 . The three-dimensional thin-film solar cell of  claim 5 , wherein said front side surface passivation layer is a thermal oxide. 
     
     
         7 . The three-dimensional thin-film solar cell of  claim 5 , further comprising an anti-reflection layer positioned on said doped emitter region. 
     
     
         8 . The three-dimensional thin-film solar cell of  claim 1 , further comprising a back side surface passivation layer positioned on said base region back surface field p-type doped base region. 
     
     
         9 . The three-dimensional thin-film solar cell of  claim 8 , wherein said back side surface passivation layer is a thermal oxide. 
     
     
         10 . The three-dimensional thin-film solar cell of  claim 1 , wherein said sunny side doped emitter region is an n-type doped emitter region.