DEFECTS INDUCED BY ELECTRON IRRADIATION IN CdSe THIN FILMS

Thin films of AIIBVI compounds are potential candidates for the manufacturing of electronic and optoelectronic devices, especially solar cells. In this paper the effects of irradiation with high-energy electrons on structural and electrical properties of CdSe thin films have been investigated. The films, 30 .tm thick, were prepared by thermal-vacuum evaporation on glass substrate at a temperature of 220 DGC. The samples were irradiated with 6-MeV electrons, up to a fluency of 1034 elcm2. XRD investigation has revealed that the films contain wurtzitetype CdSe, (001) preferentially oriented in the growth direction. The defects induced by electron irradiation have been studied using the Space Charge Limited Currents (SCLC) measurements and Thermally Stimulated Currents (TSC) spectroscopy. It was found that the electrical conduction of the samples, both before and after irradiation, is mainly controlled by a defect having an energy level located at 0.38 eV below the conduction band edge, its density was significantly increased as a result of irradiation. The possible origin of this defect is discussed.