CATHODOLUMINESCENCE AND ISOCHRONAL ANNEALING INVESTIGATIONS OF EDGE-EMISSION IN ZNTE

An investigation of the liquid helium temperature cathodoluminescence edge emission of undoped ZnTe has shown that two bands at 545. 8 and 547. 3 nm result, respectively, from free-to-bound and donor-acceptor pair recombination at a common acceptor level with a hole binding energy of 124 mev. From observations of the changes that occur in the edge-emission spectrum after isochronal (30 min) annealing treatments in vacuum in the temperature range 50-500 degree C, it is suggested either that the acceptor defect is mobile and can move out of sites at which it behaves as an acceptor to sites at which it behaves as a donor, or that during annealing complexing occurs which changes the nature of the center and effectively removes it.