Patent ID: 8129822

Claim:
A structure for use in the fabrication of a photovoltaic solar cell, said structure comprising; a reusable monocrystalline silicon template; a substantially conformal sacrificial porous silicon layer coupled to said reusable template; and an epitaxial three-dimensional monocrystalline silicon thin-film solar cell substrate deposited on said conformal sacrificial porous silicon layer; wherein said reusable template has an area at least as large as an area of said three-dimensional monocrystalline silicon thin-film solar cell substrate, said three-dimensional monocrystalline silicon thin-film solar cell substrate measuring at least 125 mm×125 mm, said reusable template having an array of structural surface topography features substantially conforming to desired structural surface topography features of said three-dimensional monocrystalline thin-film solar cell substrate; and further wherein a first subset of said structural surface topography features are positioned at predetermined locations on said template and comprise a plurality of discrete and isolated hexagonal posts defined by sidewalls and having a central axis positioned substantially perpendicular to a top surface of said reusable template, said discrete and isolated hexagonal posts associated with a set of geometrical aspect ratios and dimensions comprising a ratio between height and hexagonal diagonal dimension approximately in the range of 0.5 to 5.0; and a second subset of said structural surface topography features are positioned at predetermined locations on said template and comprise a plurality of interconnected continuous trenches interspersed among and bordering said plurality of discrete and isolated hexagonal posts and having a trench bottom width ranging at least approximately between 1 to 30 microns; said three-dimensional monocrystalline silicon thin-film solar cell substrate having a surface topography defined by said first and said second subset of said structural surface topography features of said reusable template; said reusable template, said first subset of said structural surface topography features, and said second subset of said structural surface topography features cooperating to ensure that said three-dimensional monocrystalline silicon thin-film solar cell substrate is capable of being detached from said reusable template as a free-standing, self-supporting substrate with sufficient mechanical rigidity and resilience for processing in a solar cell manufacturing environment; and said reusable template further configured to form in said three-dimensional monocrystalline silicon thin-film solar cell substrate a sunlight capturing surface structure for enabling high solar cell conversion efficiencies.