Precipitation study of lead and chalcogens in single crystals of PbSe-PbTe solid solution

Lead chalcogenides and their solid solutions exhibit a retrograde solubility of lead and chalcogens that can result in the precipitation of excess components and degradation of electrical properties when this materials are used at temperatures lower then their fabrication temperature. The kinetic of precipitation of lead and chalcogens from supersaturated single crystals PbSe, PbTe, and their solid solution has been studied in this work. Single crystals were grown from vapour phase by a sublimation procedure in a vertical quartz ampoules. Sample treatment times ranged from 2 min to several hundred hours at three temperatures for both lead- and chalcogen-saturated crystals. Based on the analysis of the kinetic data the activation energy of precipitation was estimated and compared with the activation energy of diffusion of lead and chalcogens.