Three-dimensional thin-film semiconductor substrate with through-holes and methods of manufacturing
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.
1. A three-dimensional thin-film semiconductor substrate for fabricating a partially transparent three-dimensional thin-film solar cell, comprising:
a plurality of top surface areas substantially aligned along a (100) crystallographic plane of the semiconductor substrate and defining a base opening of an inverted pyramidal surface cavity on said top surface of the semiconductor substrate;
a plurality of walls substantially aligned along a (111) crystallographic orientation plane of the semiconductor substrate wherein said walls form 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 said semiconductor substrate;
a plurality of selectively formed through-holes in said semiconductor substrate positioned between the front and back lateral surface planes of said semiconductor substrate which form a partially transparent three-dimensional thin-film semiconductor substrate.
2. The three-dimensional thin-film semiconductor substrate 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 semiconductor substrate 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 semiconductor substrate 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. 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;
a sunny side n-type doped emitter region positioned on the top surface of said semiconductor substrate and a front side surface passivation layer and an anti-reflection layer positioned on said emitter region;
a back surface field p-type doped base region positioned on the bottom surface of said semiconductor substrate and a back side surface passivation layer positioned on said base region;
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.