In situ fabricated Ga2O3–GaAs structures with low interface recombination velocity

Abstract

Amorphous Ga₂O₃ films have been deposited in situ on (100) GaAs layers grown by molecular beam epitaxy in ultrahigh vacuum. The Ga₂O₃–GaAs interface is stable during photoexcitation and the photoluminescence (PL) intensity, measured at 514.5 nm excitation wavelength, is enhanced drastically by a factor of 420 as compared to a corresponding bare GaAs surface. The Ga₂O₃–GaAs interface recombination velocity derived from a modified dead layer model is below 10⁴ cm/s. Furthermore, the PL intensity of Ga₂O₃–GaAs structures approaches that of a very low interface state density (2×10⁹ eV⁻¹ cm⁻²) AlGaAs–GaAs reference structure.