Antimony adsorption on InAs(110)

The overlayer growth of the Sb/InAs(110) interface has been investigated for room-temperature (RT) deposition and subsequent annealing, by means of Auger and core-level photoemission spectroscopy. Antimony forms an unreactive and epitaxial monolayer, followed by three-dimensional island growth. The surface electronic transitions above the semiconductor bulk gap and Sb-induced electronic states have been studied by means of photoemission and high-resolution electron-energy-loss spectroscopy. The Sb/InAs(110) interface is semiconducting and the (1×1) Sb structure, obtained after a thermal annealing at 600 K, presents a surface band gap of 0.42 eV at RT. Schottky barrier height, derived from the energy shift of the In core-level emission lines, is about 0.7 eV with respect to the valence-band maximum. The evolution of the space-charge layer with the formation of an accumulation layer has been deduced from the dopant-induced free-carrier plasmon. The accumulation layer and the Schottky barrier height are reduced when the annealing procedure reorders the surface to obtain the (1×1) two-dimensional structure.