Variety transformation of compound at GaSb surface under sulfur passivation

An elemental Sb layer, formed at the oxide/GaSb interface, causes large sur face leakage current and recombination; which are two main drawbacks of GaS b-based devices in full photoelectric application. The proportion of elemen tal Sb to other Sb compounds at the GaSb surface was increased by immersing the sample into diluted HCl solution. With sulfuring of the GaSb surface, elemental Sb was replaced by Sb2S5 and Sb oxides were removed. The mechanis m that prevents formation of the leakage path at the as-etched GaSb surface is elucidated by X-ray photoelectron spectroscopy (XPS).