Jahn, SG Hofsass, H Restle, M Ronning, C Quintel, H BharuthRam, K Wahl, Ulrich
Elsevier science bv
Journal of Crystal Growth vol:161 issue:1-4 pages:172-176
The thermal stability of substitutional Ag in CdTe was deduced from lattice location measurements at different temperatures. Substitutional Ag probe atoms were generated via transmutation doping from radioactive Cd isotopes. The lattice sites of Ag isotopes were determined by measuring the channeling effects of emitted conversion electrons. Below room temperature Ag occupies mainly substitutional lattice sites. With increasing measurement temperature the substitutional fraction of Ag atoms decreases and vanishes completely above 400 K. Simultaneously measured loss of Ag activity indicates that some of the Ag diffuses preferentially to the surface where it disappears. The remaining Ag may be trapped at extended defect complexes or precipitates. In Cd-rich CdTe we suspect an interstitial diffusion directly after the dissociation to the sinks, whereas in Te-rich CdTe this process is possibly retarded by retrapping at Cd vacancies.