Vacancy-type defects in electron and proton irradiated II-VI compounds

Positron lifetime and Doppler-broadening measurements have been performed on the wide-bandgap compound semiconductors ZnO, ZnS, ZnSe, and ZnTe to investigate the basic properties of intrinsic and radiation induced defects. The samples were irradiated either with 3 MeV protons at 223 K to a fluence of 1.2x10(18) p/cm(2) or 1 MeV electrons at 4 K to a fluence of 1x10(18) e/cm(2). The isochronal annealing was done in an Ar atmosphere. 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.