GaAs Shallow-homojunction solar cells on Ge-coated Si substrates

Solar cells with conversion efficiencies of 12% (AM1) have been fabricated from single-crystal GaAs epilayers grown by CVD on Ge-coated Si substrates. The cells utilize an n
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/p/p
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shallow-homo junction GaAs structure on a thin (<0.2 µm) epitaxial Ge layer. These solar cells are the first reported GaAs devices fabricated on Si substrates.