Thermoelectric properties of Cu-dispersed bi0.5sb1.5te3
1 Department of Materials Science and Engineering, Chungju National University, Chungju, Chungbuk 380-702, South Korea
2 Energy Materials Lab., Green Ceramic Division, Korea Institute of Ceramic Engineering and Technology, Seoul 153-801, South Korea
3 The 4th R&D Institute-4, Agency for Defense Development, Daejeon 305-600, South Korea
Nanoscale Research Letters 2012, 7:2 doi:10.1186/1556-276X-7-2Published: 5 January 2012
A novel and simple approach was used to disperse Cu nanoparticles uniformly in the Bi0.5Sb1.5Te3 matrix, and the thermoelectric properties were evaluated for the Cu-dispersed Bi0.5Sb1.5Te3. Polycrystalline Bi0.5Sb1.5Te3 powder prepared by encapsulated melting and grinding was dry-mixed with Cu(OAc)2 powder. After Cu(OAc)2 decomposition, the Cu-dispersed Bi0.5Sb1.5Te3 was hot-pressed. Cu nanoparticles were well-dispersed in the Bi0.5Sb1.5Te3 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