Abstract
Amorphous Ga 2 O 3 films have been deposited in situ on (100) GaAs layers grown by molecular beam epitaxy in ultrahigh vacuum. The Ga 2 O 3 -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 Ga 2 O 3 -GaAs interface recombination velocity derived from a modified dead layer model is below 10 4 cm/s. Furthermore, the PL intensity of Ga 2 O 3 -GaAs structures approaches that of a very low interface state density (2×10 9 eV -1 cm -2 ) AlGaAs-GaAs reference structure. © 1995 American Institute of Physics.