Thermoelectric performance of Cu-doped MoS2 layered nanosheets for low grade waste heat recovery

Transition Metal Dichalcogenides (TMDCs) are the potential thermoelectric materials due to their high thermal stability as well as tunable electronic and phonon transport properties. In this work, we investigate theeffect of copper doping in thermoelectric properties of layered MoS2 nanosheets. X-ray Diffraction analysis and HRTEM micrographs show the reduction in interatomic spacing which confirms the interaction of copper ions with MoS2 lattice. Downshift in X-ray Photoelectron Spectroscopy (XPS) of Cu doped samples proves the shift of Fermi energy near to the valence band and it results in the enhancement of electrical conductivity of Cu doped MoS2 samples from 0.75 Sm-1 to 14.20 Sm-1 (for 7.5 wt% Cu doped sample). Thus, obtained maximum power factor of 0.313 mu Wcm(-1)K(-2) for 7.5 wt% Cu doped MoS2 at 420 K.