Electrical properties, photoconductivity, and photoluminescence of coarse-grained p-ZnTe

Electrical and photoelectric properties and also low-temperature photoluminescence of coarsegrained p -ZnTe with a resistivity of 3.3 × 10 10 Ω cm at 77 K have been studied. The coarse-grained ZnTe sample in the shape of a pipe was synthesized at 730°C from vapor phase in cocurrent flows of components. X-ray structure analysis showed that there are single-crystalline grains in both the [111] and [100] directions. In spite of nonequilibrium conditions of rapid crystallization, X-ray diffractometry measurements showed that the ZnTe crystallinity is good. The results of low-temperature photoluminescence confirm that there is an ordered distribution of impurities in the lattice. The set of impurities is limited to Cu, Ag, Li, and O. The photoconductivity and photoluminescence spectra indicate that there are poorly studied centers with levels deep m the band gap. In the regions with a low density of twins, there is observed a high quantum yield of photoluminescence, the absence of transitions related to complex defects, the presence of intrinsic emission with pronounced polaritonic structure, and manifestation of an ample structure of two-hole transitions that are absent in the crystals obtained under conditions of slow growth.