Band bending and interface states for metals on GaAs

We have used soft x-ray photoemission and optical emission spectroscopies to observe a broad range of Fermi level stabilization energies at metal interfaces with GaAs(100) surfaces grown by molecular beam epitaxy (MBE). The observed metal- and As-related interface cathodoluminescence plus orders-of-magnitude differences in bulk-defect-related photoluminescence between melt- versus MBE-grown GaAs suggest a role of bulk crystal growth and processing in controlling Schottky barrier formation.