The influence mechanism of mg doping on the thermoelectric properties of ZnO electronic materials for cable channels

ZnO is one of the most promising oxide electronic thermoelectric materials in the medium and high-temperature range. The influence mechanism of Mg doping on the thermoelectric properties of ZnO was studied using powder synthesis method combined with first principles. It was found that the doping of Mg can effectively affect the Fermi level of ZnO, increase the bandgap width and density of states. The doping of Mg would introduce impurity energy levels (mainly composed of s orbitals and p orbitals), while contributing an increase in the hybridization effect between Zn/O/Mg atoms and the corresponding density of states. The electrical conductivity increases with the increase of Mg doping content throughout the entire temperature range, reaching a maximum of ∼ 141 Scm −1 at 873 K. The power factor significantly increases in the medium and high temperature range, reaching a maximum of ∼ 6.51 μWcm −1 K −2 . Mg doping can cause a decrease in the Young's modulus of ZnO, and the thermal conductivity decreases due to the decrease in lattice thermal conductivity. The ZT value has significantly increased in the medium and high temperature range, reaching a maximum of ∼ 0.26, which is ∼ 2.65 times that of undoped sample.