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US 4,370,510 AGranted
Gallium arsenide single crystal solar cell structure and method of making
AssigneeCalifornia Institute of Technology
InventorRichard J. Stirn
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AssigneeCalifornia Institute of Technology
InventorRichard J. Stirn
Estimating the term…
A production method and structure for a thin-film GaAs crystal for a solar cell on a single-crystal silicon substrate (10) comprising the steps of growing a single-crystal interlayer (12) of material having a closer match in lattice and thermal expansion with single-crystal GaAs than the single-crystal silicon of the substrate, and epitaxially growing a single-crystal film (14) on the interlayer. The material of the interlayer may be germanium or graded germanium-silicon alloy, with low germanium content at the silicon substrate interface, and high germanium content at the upper surface. The surface of the interface layer (12) is annealed for recrystallization by a pulsed beam of energy (laser or electron) prior to growing the interlayer. The solar cell structure may be grown as a single-crystal n.sup.+ /p shallow homojunction film or as a p/n or n/p junction film. A Ga(Al)AS heteroface film may be grown over the GaAs film.
A method for producing a thin-film GaAs single crystal layer for a solar cell structure on a single-crystal silicon substrate comprising the steps of
A method for producing a thin-film GaAs single crystal layer for a solar cell structure on a single-crystal silicon substrate comprising the steps of
A solar cell comprised of a single crystal silicon substrate, a single-crystal interlayer, and a single-crystal GaAs film epitaxially grown on said interlayer, said interlayer being comprised of epitaxial single-crystal semiconductor material having a closer match in lattice and thermal expansion with single-crystal GaAs than with the single-crystal silicon of said substrate, a back contact on said substrate and a grid contact on said film said interlayer being comprised of step graded germanium-silicon alloy, with low germanium content at the silicon substrate interface, and a high germanium content at the upper surface.
Dependencies are inferred from the claim text.