Equilibrium characteristics and low-temperature photoluminescence of CdTe:Pb single crystals

Using the Bridgman-Stockbarger method, CdTe:Pb single crystals with various dopant concentrations in the solution (CPb0=5×1018, 1019, and 5×1019 cm−3) were grown. Equilibrium characteristics of the material are controlled by deep acceptors with energy Ev+(0.39±0.02) eV. The hole concentration decreases as the dopant concentration increases over the entire range of variation in CPb0. The band caused by transitions in donor-acceptor pairs, as well as the edge emission band, is observed in the low-temperature photoluminescence spectra. As CPb0 increases, the intensity of the band associated with transitions from the conduction band to an acceptor in the edge region increases abruptly. The peak of the zero-phonon line of this radiation shifts to shorter wavelengths. The possible nature of transitions and the dynamics of variation in the photoluminescence spectra are analyzed in relation to the doping level.