Effects of Mn substitution on thermoelectric properties of CuIn_1-xMn_xTe₂

CuIn_1-xMn_xTe₂ samples have been synthesized by a melt-annealing method. The x-ray powder diffraction (XRD) analysis shows that the CuIn_1-xMn_xTe₂ samples crystallize in the chalcopyrite phase. Mn doping can effectively optimize the electrical properties and accordingly improve the power factor. The room temperature electrical conductivity of doped CuInTe₂ increases by several orders of magnitude due to substituting In with Mn. In addition, a large reduction in thermal conductivity is achieved through the enhanced phonon scattering via Mn-related point defects and precipitates. Therefore, an enhanced average ZT value up to 0.34 is achieved for sample CuIn_0.925Mn_0.075Te₂, which is 41% higher than that of the pristine CuInTe₂.