Thermoelectric properties of p-type semiconductors copper chromium disulfide CuCrS2+x

A series of bulk samples CuCrS2+x (x = 0, 0.01, 0.02, 0.06, 0.10) were prepared by combining mechanical alloying and spark plasma sintering. The effect of excessive sulfur content on the phase structure, microstructure, and thermoelectric and optical properties was investigated. The excessive sulfur initially entered into the lattice sites and then into the lattice interstices. A direct band gap semiconductor for CuCrS2 material with an optical band gap of about 2.48 eV was proved. An improved electrical conductivity 2980 S m−1 at 673 K reached along with an inversely varied Seebeck coefficient as increasing x value, which showed a maximum power factor of 104 μ W m−1 K−2 at 673 K for CuCrS2.01 sample. In addition to the low thermal conductivity between 0.48 and 1.02 W m−1 K−1 in the whole temperature range, a peak ZT of 0.15 was achieved at 673 K for CuCrS2.01 bulk sample, which was 36 % higher than that (0.11) of the CuCrS2.00.