Structural and electrical investigation of implantation damage annealing in CdTe

CdTe crystals were implanted with Cd-111m ions at 60 keV and annealed under well-defined partial pressure conditions. The occupation of unperturbed lattice sites was monitored by perturbed angular correlation spectroscopy (PAC), the loss of Cd from the sample by tracer diffusion and the creation of electrically active defects by deep-level transient spectroscopy (DLTS). The implanted Cd atoms occupy substitutional sites immediately after room-temperature implantation and small deviations from a perfectly crystalline environment disappear already after annealing at 673 K. In Cd-rich (i.e. n-type) CdTe, a strong out-diffusion of Cd occurs. None of the observed electrically active deep levels are correlated to the implantation of Cd.