Effect of grain boundaries on the properties of cadmium telluride grown under nonequilibrium conditions

Microphotoluminescence spectroscopy and imaging were used to study the effect of grain boundaries on the properties of textured CdTe polycrystals with a single-crystal grain size of 1–2 mm grown under nonequilibrium conditions. The technological procedure included low-temperature synthesis and purification of the material via congruent sublimation, with subsequent deposition under conditions of gas-dynamic vapor flow and high-rate low-temperature condensation. Microluminescence probing revealed that most of the grain boundaries are decorated with local centers emitting in the 1.4-eV band of donor-acceptor recombination involving shallow donors and A-center acceptors. The boundary regions are, to some extent, free of nonradiative recombination centers active at room temperature. Gettering activity of the grain boundaries could be detected at the distances up to 100 µm, which reflects the specific features of the nonequilibrium crystallization conditions of the material under study.

Перевод пока недоступен