Lattice thermal conductivity of CdxZn1−xX (X=O, S, Se, Te) from first principles

Abstract A systematic first principles study has been carried on binary Zinc Chalcogenides and their Cd-substituted ternary alloys for the measurement of thermal conductivity ( κ ) over a wide range of temperature (300 K-1200 K) and pressure (0 GPa-10 GPa). The various parameters (Gruneisen parameter and Debye temperature) required to measure κ are first determined by using quasi harmonic Debye model and then Slack’s equation is used to get valuable results. At ambient conditions, it is found that thermal conductivity of ZnX decreases along the Chalcogen’s group (O, S, Se, Te) due to decreasing contribution of acoustic phonons. A net decrease in κ is found by substituting the Cd in Zn Chalcogenides due to impurity scattering and which in turn increase the thermal resistance. The effects of temperature and pressure on κ for Cd-substituted ZnX are also displayed and discussed. The results are compared to available experimental and theoretical data in order to validate the approach used in the article.