Thermally-Stimulated Current of Zinc Selenide Heat-Treated in Controlled Partial Pressures of Constituent Elements

The purpose of the present investigation is to obtain information on the trap levels related to native defects. TSC (thermally-stimulated current) measurements were made on vapor-grown ZnSe single crystals heat-treated in Zn or Se vapor in order to control the deviation from stoichiometry. Two TSC peaks were observed near 150 K and 180 K which were identified as having originated from two electron trap levels at 0.19±0.04 eV and 0.31±0.04 eV, respectively, below the bottom of the conduction band. These trap levels may be explained as a result of the trace impurity defects whose concentrations increase with increase of Zn concentration or the associated defects consisting of a native defect ( V Se or Zn i ) and impurity.