Interface chemistry of H2O on GaAs nanowires probed by near ambient pressure X-ray photoelectron spectroscopy

Abstract

Interface chemistry of H2O on GaAs nanowires is investigated by in situ X-ray photoelectron spectroscopy (XPS) at elevated water vapor pressures (from UHV to 5mbar) and temperatures (from room temperature to 400°C). Surface-assisted water dissociation leads to oxidation and hydroxylation of surface Ga atoms. In comparison with the simple planar GaAs(100) crystal, the H2O dissociation process on GaAs nanowires is greatly enhanced at elevated pressures and temperatures.