Study of the Interface Properties of CuInSe2 Single-Crystal Heterojunctions and Schottky Barriers

High resolution photoluminescence measurements performed at different excitation powers and different temperatures (7.8-90 K) are used to identify the origin and location of the various defect levels in single-crystal CuInSe₂. Extrinsic radiative recombination surface states resulting from surface and heat treatments during the device fabrication steps have been determined. The correlation between the type and relative concentration of the intrinsic defect states dominating a particular surface of the material and the junction characteristic of the devices fabricated on that surface are noted.