BORON IMPLANTATION INTO CDTE

The behaviour of B-12 implanted into p-type, highly resistive n-type a nd n-type CdTe is investigated by the beta-NMR method. At the Larmor f requency a single line resonance shows up which indicates that a measu rable boron fraction is in a diamagnetic charge state and occupies pos itions with cubic environment. This boron population is about 15% in h ighly resistive n-type CdTe at room temperature and rises with increas ing implantation temperature. In CdTe:Cd and CdTe:Te crystals the cubi c boron fraction starts from a value of 10%. Activation energies, whic h are deduced from the data, are similar for highly resistive n-type C dTe and CdTe:Cd (0.39(5) and 0.44(5) eV, respectively), but are differ ent in case of CdTe:Te (0.71(5) eV) indicating different annealing pro cesses. Only in CdTe:Cd a boron population that is exposed to defects is detected by the Delta m = 2 NMR transition. These defects are chara cterized by a mean electric field coupling constant of 210(20) kHz.