Photoluminescence properties of GaSb epitaxial layers passivated in hydrogen plasma

Undoped and Si-doped GaSb layers grown by low pressure MOVPE have been treated in hydrogen plasma and the effect of this treatment on photoluminescent (PL) and electrical properties is presented. Hall-effect and PL measurements reveal that hydrogenation, leads to reduction in the concentration of electrically active native acceptors, while the concentration of shallow acceptor Si-Sb remain practically unaffected. The hydrogenation of layers grown at Sb rich conditions results in nearly complete quenching of the PL line peaking at 896.5 meV, denoted in the literature as BE4. The origin of the BE4 line is ascribed to radiative recombination of excitons bound to a "bare" gallium vacancy. (c) 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.