Enhancement of thermoelectric power factor of zinc oxide by nickel and indium dual doping

Abstract

Effect of structural and morphological deformation on the enhancement of thermoelectric properties of zinc oxide due to the dual substitution of indium and nickel was investigated. The doped materials resemble the hexagonal wurtzite structure of the host material, with increased crystallite size and strain, indicating the inclusion of the cations with larger radius. Reduction in the optical band gap energy from 3.1 eV to 2.20 eV is observed with a red shift in the absorption edge. The donor cations doped samples have high charge carrier density, resulting an increase in the transport properties. Highest electrical conductivity and seebeck coefficient were obtained for the doped samples leading to a hike in the power factor of 1427 μW/mK 2 . The thermal conductivity decreased with doping concentration, and highest figure of merit of 0.11 was obtained.