Photoemission studies of Mg deposition on sulfurized GaSb(100) surface

摘要

Synchrotron Radiation Photoemission Spectroscopy (SRPES) has been used to investigate the chemical states and electronic states of a [NH_4]_2S_x treated GaSb(100) surface. We have found that the oxides of Ga and Sb are removed and the sulfides of Ga and Sb are formed on the surface. After sulfurized GaSb(100) was annealed, the Sb-S bond is broken to form elemental Sb, while the Ga-S bonds terminate the surface; these results imply that ammonia sulfide has a passivating role for GaSb. At room temperature (RT), deposited Mg on passivated surface has been also investigated. It is found that Ga atoms can be exchanged by Mg atoms and diffuse into Mg overlayer. Moreover, the Schottky barrier height of the Mg overlayer on the sulfurized GaSb surface was determined to be about 0.3 eV.