InGaAs/GaAsP quantum wells and wires for high-efficiency photovoltaic applications

Abstract

Layer undulation of InGaAs/GaAs/GaAsP strain-balanced quantum well superlattice forms InGaAs nanowires along the bunching steps on a vicinal substrate embedded in the GaAs/GaAsP matrix. When it is used as an absorber in a GaAs single-junction cell, it assists carrier escape from narrow-gap InGaAs and extends photoluminescence lifetime as compared with a planar superlattice. Such a wire structure can be superior to existing quantum wells as a band-gap adjuster of a middle cell for improved current matching and efficiency.