Schottky properties of CuInSe2 single crystals grown by the horizontal Bridgman method with controlling Se vapor pressure

The electrical properties of the Schottky barriers fabricated by using good quality single crystals of CuInSe2 grown by the horizontal Bridgman method with controlling Se vapor pressure have been investigated, since the Schottky effect gives us useful information concerning defect physics. The electrical resistivities, Hall coefficients and mobilities are measured as a function of temperature down to 20 K, and the activation energy EA and the density NA of acceptors are estimated. Schottky junctions are prepared by vacuum evaporation of Al or In on chemically etched surfaces of the samples. From the current-voltage characteristics of these junctions, the ideality factor and barrier height are estimated as 3.6–4.8 and 0.60–0.61 eV for junctions using Al, and as 1.9–3.0 and about 0.54–0.59 eV for those using In. The capacitance-voltage characteristics are also measured. Based on these results, it is expected that the prepared junctions do not follow the Schottky model, but rather obey the MIS one.