Synthesis and Thermoelectric Properties of ZnO/Cu2SnSe3 Composites
Addition of nanoparticles into bulk materials is an efficient way to enhance the performance of thermoelectric materials. The nanoZnO particles were introduced into the Cu2SnSe3 matrix by ball milling method, and the ZnO/Cu2SnSe3 composites were fabricated by spark plasma sintering (SPS) technology. The phase constitution and microstructure were characterized by XRD, FESEM. The effects of nanoZnO particles on the electrical and thermal transport were investigated and discussed. The diffraction spectra of all composites samples well corresponded to that of the matrix diffraction plane. The nanoZnO agglomerated into irregular clusters with the size lager than 200nm and distributed on the grain boundary or the surface of Cu2SnSe3 grain, which significantly reduce the lattice thermal conductivity by scattering middle-long wavelength phonons. The optimal ZT value was obtained from the composite sample of 2.4 vol. % ZnO, which is 1.3 times as large as that of the Cu2SnSe3 matrix.