Characterization of thermal properties of Cd1−x−yZnxMgySe mixed crystals by means of photopyroelectric and infrared imaging techniques

In this work a complete thermal characterization of Cd1−x−yZnxMgySe mixed crystals was carried out. Bulk Cd1−x−yZnxMgySe semiconductors with different x and y contents were grown from the melt by the modified high pressure Bridgman method. The photopyroelectric (PPE) method in the back configuration (BPPE) and the infrared (IR) lock-in thermography were applied to measure the thermal diffusivity. Values of thermal effusivity of the samples were obtained with the PPE technique in the front configuration (FPPE), coupled with a thickness thermal wave resonator cavity (TWRC) scanning procedure. Measured thermal effusivity together with the thermal diffusivity allowed calculating the thermal conductivity of the investigated materials. For the calculation of the specific heat, the densities of the samples were calculated from their weight and geometry. The effect of Mg/Zn molar ratio on thermal properties of these quaternary Cd1−x−yZnxMgySe compounds was analyzed and discussed.