Pulsed laser-induced photochemical decomposition of GaAs(110) studied with time-resolved photoelectron spectroscopy using synchrotron radiation

Abstract
Cleaved GaAs surfaces decompose under weak pulsed-laser irradiation, leading to the formation of metallic Ga islands. The reduction of band bending nonuniformities in photoemission spectra acquired during the laser pulses, in concert with new core-level fitting techniques which treat broadened spectra, permits a detailed analysis. A decomposition rate consistent with a two-step photochemical excitation process is measured. The surface remains largely intact on an atomic scale, but is increasingly unable to support excited surface states as decomposition proceeds.