Low-temperature photoluminescence of II-VI films obtained by close-spaced vacuum sublimation

Low-temperature photoluminescence (PL) spectra of CdTe and ZnTe films obtained by a close-spaced volume sublimation technique under different technological conditions (substrate temperatures) were investigated. Analysis of the experimental results made it possible to conclude that the nature of the structure of the PL spectra observed experimentally is caused by the recombination of the excitons bound to shallow neutral acceptors, donor-acceptor pairs with the participation of the complex acceptors, and the presence of the extended defects like dislocations. The presence of neutral acceptors is related to the Li, Na, P or Cu residual impurities. As a result of the study of the PL spectra of CdTe and ZnTe films the optimal temperature conditions of their growth were determined as the substrate temperature T-s=623 K and 673 K, respectively. (C) 2012 Elsevier B.V. All rights reserved.