Thermoelectric properties of Cu-dispersed bi0.5sb1.5te3

A novel and simple approach was used to disperse Cu nanoparticles uniformly in the Bi 0.5 Sb 1.5 Te 3 matrix, and the thermoelectric properties were evaluated for the Cu-dispersed Bi 0.5 Sb 1.5 Te 3 . Polycrystalline Bi 0.5 Sb 1.5 Te 3 powder prepared by encapsulated melting and grinding was dry-mixed with Cu(OAc) 2 powder. After Cu(OAc) 2 decomposition, the Cu-dispersed Bi 0.5 Sb 1.5 Te 3 was hot-pressed. Cu nanoparticles were well-dispersed in the Bi 0.5 Sb 1.5 Te 3 matrix and acted as effective phonon scattering centers. The electrical conductivity increased systematically with increasing level of Cu nanoparticle dispersion. All specimens had a positive Seebeck coefficient, which confirmed that the electrical charge was transported mainly by holes. The thermoelectric figure of merit was enhanced remarkably over a wide temperature range of 323-523 K. PACS : 72.15.Jf: 72.20.Pa