Enhancement of Thermoelectric Figure of Merit in Ternary Silver Thallium Tellurides by Controlling the Carrier Concentration

Abstract

We tried to improve the thermoelectric figure of merit of a ternary silver thallium telluride, Ag₉TlTe₅, by controlling the carrier concentration. We studied the effect of deviation from the stoichiometric composition by measuring the thermoelectric properties from room temperature to slightly below the melting temperature of polycrystalline Ag₉TlTe₅ with different nominal compositions. A minimal compositional deviation of Ag₉TlTe₅ improved the power factor while the thermal conductivity remained extremely low, leading to an enhancement of the thermoelectric figure of merit