Influence of low-temperature annealing on Schottky barrier height and surface electrical properties of semi-insulating CdTe

Abstract We investigated the influence of low-temperature annealing in ambient air on the fundamental properties of semi-insulating CdTe doped with In and Cl in planar configuration, with gold and indium contacts prepared by evaporation at temperatures up to 373 K. The Au contact was formed by a central electrode and a guard ring, which allows us to separate bulk and surface leakage currents. We measured I–V characteristics and ellipsometry after each annealing step at room temperature. We determined that the change of the Schottky barrier height is responsible for the change of the bulk current, while the surface leakage current is affected by TeO ₂ layer thickness.