Thermoelectric properties of Ni-doped CuInTe2

•Transport properties of Cu1−xNixInTe2 samples were explored in temperature range 300–675 K.•Limit of solubility of nickel in Cu1−xNixInTe2 lies in the vicinity of x=0.02.•Non-monotonous behavior of transport properties was explained within a point defect model.•The maximum ZT at 475 K is by 50% higher than that for undoped sample.

Polycrystalline samples of composition Cu1−xNixInTe2 (for x=0–0.05) were synthesized from elements of 5 N purity using a solid-state reaction. The phase purity of the products was verified by X-ray diffraction. Samples for measurement of the transport properties were prepared using hot-pressing. The samples were then characterized by the measurement of electrical conductivity, the Hall coefficient, the Seebeck coefficient, and the thermal conductivity over a temperature range of 300–675 K. All of the samples demonstrate p-type conductivity. We discuss the influence of Ni substitution on the free carrier concentration and the thermoelectric performance. The investigation of the thermoelectric properties shows an improvement up to 50% of ZT in the temperature range of 300–600 K.