Thermoelectric properties of Cu-dispersed bi(0.5)sb(1.5)te(3)

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