INFLUENCE OF GAMMA-IRRADIATION ON THE OPTICAL AND ELECTRICAL-PROPERTIES OF ZNIN2SE4 FILMS

ZnIn2Se4 films were prepared by thermal evaporation under vacuum (10(- 5) torr) on glass substrate at 300 degrees C. The optical constants (a bsorption coefficient alpha, refractive index n and extinction coeffic ient k) of unirradiated and irradiated ZnIn2Se4 films were calculated. The values of allowed direct and indirect optical energy gaps of ZnIn 2Se4 films increased from 3 to 3.2 eV and from 1.75 to 1.9 eV with inc reasing the gamma-doses from zero to 7.5 Mrad, respectively. The irrad iated films have lower conductivity than those as-deposited films (uni rradiated). The activation energy (Delta E) increases from 0.89 to 0.9 5 eV with increasing gamma-doses to 7.5 Mrad. (C) 1997 Elsevier Scienc e Ltd.