Compositional difference of thermoelectric properties in Ag 9TlTe5

Abstract

The ternary silver thallium telluride, Ag9TlTe5, was reported to exhibit an excellent thermoelectric performance because of its extremely low thermal conductivity. We have studied the effect of the compositional difference on thermoelectric properties of Ag9TlTe 5 by measuring the thermoelectric data on polycrystalline samples with three compositions. A minimal compositional deviation from the stoichiometric Ag9TlTe5 improved the power factor while the thermal conductivity remained extremely low, leading to an enhancement of the thermoelectric figure of merit. © 2006 The Japan Institute of Metals.