Thermoelectric properties of polycrystalline In4Se3 and In4Te3

High thermoelectric performance of a single crystal layered compound In4Se3 was reported recently. We present here an electrical and thermal transport property study over a wide temperature range for polycrystalline samples of In4Se3 and In4Te3. Our data demonstrate that these materials are lightly doped semiconductors, leading to large thermopower and resistivity. Very low thermal conductivity, below 1 W/m K, is observed. The power factors for In4Se3 and In4Te3 are much smaller when compared with state-of-the-art thermoelectric materials. This combined with the very low thermal conductivity results in the maximum ZT value of less than 0.6 at 700 K for In4Se3. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3389494]