Thermodynamic Calculations and Growth of ZnSe Single Crystals by Chemical Vapor Transport Technique

Abstract

A thermodynamic model has been proposed for the growth of ZnSe single crystals by the chemical vapor transport (CVT) method using iodine as the transporting agent. The optimum growth conditions for the growth of good quality ZnSe single crystals have been investigated theoretically using partial pressure values of I, I2, ZnI2, and Se2, which were calculated empirically at different growth temperatures and for different iodine concentrations, present inside the growth ampule. The diffusion-limited transport rates have also been calculated by taking into consideration the growth temperature, the ampule length, the total pressure present inside the ampule, and the partial pressures of ZnI2 at growth and source zones. The change in supersaturation ratio with respect to temperature and initial iodine concentration has also been calculated using this numerical model. The optimum growth temperature for the ZnSe−I2 system has been predicted from the theoretical results. Experiments were carried out for the growth...