The potential thermoelectric material Tl 3 XSe 4 (X = V, Ta, Nb): a first-principles study.

Searching for materials with a high thermoelectric figure of merit ( ZT ) has always been the goal of scientific researchers in the energy field. Here, we combine first-principles calculations to obtain the thermoelectric characteristics of Tl 3 XSe 4 (X = V, Nb, or Ta). First, we compared the phonon thermal transport characteristics of Tl 3 XSe 4 by solving the Boltzmann transport equation and calculated the thermal conductivity. After that, we obtained the thermoelectric properties of Tl 3 XSe 4 through the relaxation time approximation theory. The results show that Tl 3 XSe 4 has a high Seebeck coefficient, high electrical conductivity, high power factor (PF) and low thermal conductivity contributed by both phonons and electrons. At the same time, the ZT value of Tl 3 XSe 4 shows that it is a potential thermoelectric material with excellent performance. This work demonstrates the thermoelectric transport characteristics of Tl 3 XSe 4 to explore its potential applications in many other fields of thermoelectricity and energy.