Molecular beam epitaxial GaAs heteroface solar cell grown on Ge

Abstract

GaAs/AlGaAs heteroface solar cells having AM1 efficiencies up to 17% have been grown by molecular beam epitaxy (MBE) directly on Ge (100) substrates. These cells on Ge have efficiencies identical to cells grown simultaneously on GaAs. The cells reported here are the highest efficiency MBE solar cells reported to date, and are the first high-efficiency GaAs solar cells grown directly on Ge by MBE.