ATOMIC-STRUCTURE OF ACCEPTORS IN CD0.22HG0.78TE - DISCRIMINATION BETWEEN VACANCIES AND IONS BASED ON POSITRON LIFETIME AND HALL DATA

We demonstrate that positron annihilation provides a direct method to separate vacancy-type and ion-type accepters in p-type Cd0.22Hg0.78Te crystals. We show how to combine positron and Hall data to obtain the concentrations of accepters, both types, and donors. In crystals with a low concentration of negative ions, there is clear evidence that the vacancies have two ionization levels 2- --> 1- and 1- --> 0.