It was noted that the positron annihilation technique was a unique tool for the study of Hg vacancy defects in this material. The sensitivity constant of the method was determined by means of post-growth annealing and Hall-effect measurements. Iso-concentration lines of Hg vacancies were determined within the region of existence of the compound in the solid-vapor 2-phase field diagram. The kinetics of post-growth annealing, as studied by the use of positron lifetime measurements, provided strong evidence that the simple vacancy model for Hg diffusion was not applicable. An extended model which also included Hg interstitials was able to describe the experimental findings. The distribution of Hg vacancies within a complete (Cd,Hg)Te ingot was studied by cutting it into wafers. It was found that the vacancy concentration was rather high at the end of the crystal, due to a quenching effect which occurred during cooling of the sample after growth. The annealing behavior of low-temperature irradiation-induced defects was quite complex. Three annealing stages were observed. Two of them (below 200K and at 350K) were attributed to vacancy defects.

R.Krause-Rehberg, T.Abgarjan, A.Polity, M.Neubert: Materials Science Forum, 1995, 196-201, 1285-90