Review of defect investigations by means of positron annihilation in II-VI compound semiconductors

An overview is given on positron annihilation studies of vacancy-type defects in Cd-and Zn-related II-VI com pound semiconductors. The most noticeable results among the positron investigations have been obtained by the study of the indium-or chlorine-related A centers in as-grown cadmium telluride and by the study of the defect chemistry of the mercury vacancy in Hg1-xCdxTe after post-growth annealing. The experiments on defect generation and annihilation after low-temperature electron irradiation of II-VI compounds are also reviewed. The characteristic positron lifetimes are given for cation and anion vacancies.