Enhanced thermoelectric efficiency of Cu2-xSe-Cu2S composite by incorporating Cu2S nanoparticles

The study of thermoelectric transport properties in Cu 2-x Se and Cu 2 S has gained an importance in the thermoelectric research during last few years due to their superionic behavior and low cost. Here, we reported a facile method to enhance the thermoelectric efficiency of Cu 2-x Se by introducing Cu 2 S nanoparticles (NPs) in the matrix of Cu 2-x Se. The observed efficiency is a direct result of simultaneous improvement of Seebeck coefficient (S) because of the external strain induced by Cu 2 S nanoinclusions in Cu 2-x Se and decline in the total thermal conductivity by suppressing both electronic and lattice thermal contributions. Such higher S and lower thermal conductivity is realized for a composite structure with 10 wt% nanoinclusions of Cu 2 S which effectively contributed to higher ZT value of 0.90 at moderate temperature of 773 K. Thus, it is believed that the proposed hybrid structure is a promising p-type thermoelectric material for mid-temperature range energy harvesting applications