Surface electronic properties of clean and S-terminated InSb(001) and (111)B

The electronic properties of clean and sulfur-terminated surfaces of InSb(001) and (111) B are investigated using x-ray photoemission spectroscopy and high-resolution electron energy loss spectroscopy. The clean surfaces exhibit upward band bending (electron depletion) consistent with the charge neutrality level in InSb lying at the valence band maximum. The surface Fermi level to valence band maximum separation is increased for the S terminated compared with the clean surface, leading to flat bands and downward band bending (electron accumulation) for the (001) and (111) B surfaces, respectively. This is discussed in terms of compensation of native acceptor surface states. (C) 2008 American Institute of Physics. [DOI: 10.1063/1.3000567]