Effects of transport direction and carrier concentration on the thermoelectric properties of AgIn5Te8: A first-principles study.

Graphical abstract Highlights • The anisotropic thermoelectric properties of AgIn 5 Te 8 are identified. • The carrier concentration significantly impacts on the thermoelectric properties. • The lattice thermal conductivity is obtained and agrees to the experimental data. • The maximum ZT of 2.28 is achieved for p -type AgIn 5 Te 8 at 700 K along xx direction. Abstract The synthesis of AgIn 5 Te 8 is realized and the thermoelectric properties dependent on temperature is examined. However, the mechanism remains unclear and the synergistic effect of the temperature and the carrier concentration on thermoelectric properties is not explored. Here, the electronic transport properties are calculated by using the first-principles density functional theory combined with the semi-classical Boltzmann transport theory. The relaxation time is estimated by the deformation potential theory. The lattice thermal conductivity is evaluated by the Slack's model, and the result is in good agreement with the experimental value. High anisotropic behavior is identified for the thermal and electronic transport properties, which supports the experimental observation. By tuning the carrier concentration and temperature, a maximum thermoelectric figure of merit of 2.28 can be achieved for p -type AgIn 5 Te 8 in xx direction. The present results provide insight into the thermoelectric properties of AgIn 5 Te 8 and a guide to prepare thermoelectric materials with AgIn 5 Te 8. [ABSTRACT FROM AUTHOR]