Vacancy-type defects in electron and proton irradiated ZnO and ZnS

In this contribution, we present a study aimed at investigating basic properties of radiation induced defects in ZnO and ZnS. Positron annihilation experiments (both lifetime and Doppler-broadening measurements) were performed on polycrystalline samples. For ZnO it was found that both electron and proton irradiation caused significant changes in the positron annihilation characteristics and several annealing stages were observed, related to the annealing of variously sized vacancy complexes. The lifetime in defected, proton irradiated polycrystalline ZnS samples, grown by chemical vapour deposition, indicates the formation of large defect complexes. The annealing of proton irradiated ZnS in air at temperatures between 650 °C and 750 °C leads to significant oxidation and transformation into ZnO.