Vanadium: A Protean Dopant in SnTe for Augmenting Its Thermoelectric Performance

Abstract

In this work, a second n-type resonant dopant in the form of vanadium is introduced in the SnTe thermoelectrics family. The electronic structure simulated using density functional theory calculations revealed that V not only opens the band gap but also causes convergence of both valence and conduction sub-bands. Apart from introducing the resonance levels at the Fermi energy, the unique trait exhibited is the Rashba splitting of the conduction band to introduce multiple valleys. The advantage is the proximity of these features to the Fermi level, which eliminates the need for a co-dopant to harness the benefits. The Boltzmann transport calculations predicted promising transport properties, which showed the dual nature of vanadium, being capable of acting as a p-type as well as an n-type dopant in SnTe with corresponding maximum ZT values of 1.66 and 1.31, respectively, at 800 K, thus making it a highly potential high-performance thermoelectric candidate for future experimental studies. © 2021 American Chemical Society