Synchrotron radiation study of Rb/p-GaSb(110) interface formation and band bending at low temperature

Abstract

The formation of the Rb/p-GaSb(110) interface at liquid-nitrogen temperature is investigated by soft X-ray photoemission spectroscopy using synchrotron radiation. We use the Ga 3d and Sb 4d core levels to monitor the band bending during the interface formation. The deposition of Rb induces an overshoot of 0.3 eV with a final pinning position near the valence-band maximum. The band bending could be explained by the existence of donor levels located at about 0.3 eV above the valence-band maximum. The interface formed at low temperature was found to be much less reactive than observed previously in room-temperature studies.