Thermoelectric transport investigations on Cd/In substituted β-Zn4Sb3 compounds

beta-Zn4Sb3 compound is known to be one of the potential thermoelectric (TE) material by exhibiting low thermal conductivity with good electrical transport properties. In the present work, the effect of Cd/In doping in beta-Zn4Sb3 system has been studied. The structural refinement of the prepared compounds with beta phase Zn4Sb3 system is found by Rietveld analysis. The compounds show high electrical conductivity with enhanced Seebeck coefficient values. By increasing the disorder due to substitution of impurity atoms on main and interstitial sites Zn atoms, the heat-carrying phonons are largely scattered and reduces the thermal conductivity. High ZT value of similar to 1.3 is obtained in Zn3.9Cd0.1Sb3 compound at 680 K where as the Zn3.5Cd0.5Sb3 compound exhibits a ZT value of similar to 0.43. The In substituted samples show decreased ZT values of similar to 0.3.