Determination of Sm2O3∕GaAs heterojunction band offsets by x-ray photoelectron spectroscopy

Abstract

X-ray photoelectron spectroscopy was used to measure the energy discontinuity in the valence band (ΔEV) of Sm2O3∕GaAs heterostructures in which the Sm2O3 was grown by rf plasma-assisted molecular beam epitaxy on top of GaAs substrates. A value of ΔEV=2.63±0.10eV was obtained by using the Ga 3d energy level as a reference. Given the bandgap of 5.1eV for the Sm2O3, this would indicate a conduction band offset ΔEC of 1.13±0.10eV in this system.