Anion exchanged Cl doping achieving band sharpening and low lattice thermal conductivity for improving thermoelectric performance in SnTe

Abstract

Band structure modification plays an important role in improving thermoelectric performance of SnTe. Herein the band sharpening as one of band structure modifications is achieved by Cl doping reduces the...

Enabling High Quality Factor and Enhanced Thermoelectric Performance in BiBr3-Doped Sn0.93Mn0.1Te via Band Convergence and Band Sharpening

“…Accordingly, a maximum ZT value (ZT max ) of ∼1.31 at 873 K and an average ZT (ZT ave ) of ∼0.62 between 300 and 873 K are achieved in Sn 0.93 Mn 0.1 Te-0.8 atom % BiBr 3 . This remarkable TE performance surpasses those of Mn single doping and other reported band convergence and anion-doped SnTe-based materials, such as ZT max ≈ 1.05 and ZT ave = 0.51 at 873 K in Sn 0.93 Mn 0.1 Te, ZT max ≈ 1.15 and ZT ave ≈ 0.34 at 860 K in SnTe−Mg,28 ZT max ≈ 0.78 and ZT ave ≈ 0.29 at 873 K in SnTe−Cl,21 as well as ZT max ≈ 1.27 and ZT ave ≈ 0.48 at 873 K in SnTe−BiCl 3 ,68 which are shown in Figure5c,d, respectively. This work demonstrates that successive strategies of band convergence and band sharpening are feasible methods to enhance the TE performance in SnTe-based TE materials.…”

“…Electrically, according to Mott’s express and Drude model, S and σ are coupled with each other via the carrier concentration − where k B is the Boltzmann constant, e is the electron charge, h is the Plank constant, m d * is the density of states (DOS) effective mass, n is the carrier concentration, and μ is the carrier mobility. To obtain an optimal PF, the carrier concentration optimization utilizing the heterovalent substitution doping (such as SnTe–Bi, SnTe–Sb, , SnTe–Cl, SnTe–Br, and SnTe–I) and the self-compensation Sn doping − can facilitate a delicate trade-off between S and σ . In addition, the strategies of band structure modification, such as band convergence ,− and resonance effect, ,− are successfully devoted to modifying m d * and thus strengthening the upper limit of the optimal PF.…”

A case of perfect convergence of light and heavy hole valence bands in SnTe: the role of Ge and Zn co-dopants

“…4,10–15 SnTe, a rock salt analogue of PbTe, initially thought to be a poor thermoelectric material due to high carrier concentration and unfavorable electronic structure, is now at the forefront due to implementation of strategies like electronic structure and phonon band structure engineering to improve the power factor, while simultaneously decreasing the thermal conductivity. 16–42…”