COMPLEX-FORMATION IN IN-DOPED AND AG CU-DOPED CDTE/

Interactions between In donors and Ag, Cu and acceptor-like native def ects have been studied in p- and n-type CdTe single crystals by pertur bed angular correlation (PAC) spectroscopy on In-111 probe atoms. Silv er diffusion into the p-type samples at room temperature results in th e formation of a distinct complex characterized by an interaction freq uency eQV(zz)/h = 60.1 MHz and an asymmetry parameter eta = 0.15. At r oom temperature the relative fraction of this complex increases within a few hours and decreases with a significantly longer time constant. After copper doping, a similar complex with 57.5 MHz and eta = 0.16 wa s observed which, however, did not show any decrease. The observed beh aviour is explained by fast diffusion of Ag (or Cu) via an interstitia l mechanism and the interaction with cation vacancies. Finally, In-Ag (or In-Cu) complexes are formed.