Enhanced thermoelectric efficiency of Cu2-xSe-Cu2S composite by incorporating Cu2S nanoparticles
The study of thermoelectric transport properties in Cu2-x Se and Cu2S 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 Cu2-x Se by introducing Cu2S nanoparticles (NPs) in the matrix of Cu2-x Se. The observed efficiency is a direct result of simultaneous improvement of Seebeck coefficient (S) because of the external strain induced by Cu2S nanoinclusions in Cu2-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 10wt% nanoinclusions of Cu2S which effectively contributed to higher ZT value of 0.90 at moderate temperature of 773K. Thus, it is believed that the proposed hybrid structure is a promising p-type thermoelectric material for mid-temperature range energy harvesting applications.