Photovoltaic cell with back-surface reflectivity scattering
AssigneeAlliance for Sustainable Energy, LLC
InventorsHOWARD M. BRANZ, Charles Teplin, Pauls Stradins
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Abstract
Crystal oriented photovoltaic cells with increased efficiency are disclosed herein. In an exemplary embodiment, a photovoltaic device includes a metal substrate with a crystalline orientation comprising a diffracting structure integrated into a surface of the metal substrate. The photovoltaic device includes a heteroepitaxial crystal silicon layer having the crystalline orientation of the metal substrate and a heteroepitaxially grown buffer layer having the crystalline orientation. The buffer layer is positioned adjacent to the surface of the metal substrate having the diffracting structure.
Claims23
A photovoltaic device comprising:
- a metal substrate with a crystalline orientation comprising a diffracting structure integrated into a surface of the metal substrate;
- a heteroepitaxial crystal silicon layer having the crystalline orientation of the metal substrate;
- and
- a heteroepitaxially grown buffer layer having the crystalline orientation, the buffer layer positioned adjacent to the surface of the metal substrate having the diffracting structure.
A solar cell comprising:
- a nickel tungsten substrate with a crystalline orientation;
- a heteroepitaxially grown buffer layer having the crystalline orientation;
- a metal layer positioned between the buffer layer and the substrate, the metal layer comprising a metal having a higher reflectivity than nickel;
- and
- a heteroepitaxial crystal silicon layer grown over the buffer, the crystal silicon having the crystalline orientation of the metal substrate.
A method for increasing back surface reflectivity of a photovoltaic cell comprising:
- forming an approximately 2-10 nanometer reflective layer over a metal substrate, the reflective layer having a higher reflectivity than the metal of the metal substrate;
- heteroepitaxially growing a buffer layer and a crystal silicon layer, the buffer layer being located between the reflective layer and the crystal silicon layer, wherein each of the metal substrate, buffer layer and crystal silicon layer has a common crystal orientation.
A photovoltaic cell comprising:
- a nickel tungsten substrate with a crystalline orientation comprising a rough topography surface;
- a heteroepitaxial crystal silicon layer having the crystalline orientation of the metal substrate;
- and
- a heteroepitaxially grown buffer layer having the crystalline orientation, the buffer layer being positioned between the crystal silicon layer and the substrate.
Dependencies are inferred from the claim text.