Work

Dual character of Zn impurity in SnTe: Tuning thermoelectric and topological properties

Year: 2026

Type: article

Abstract: We present a first-principles study of the electronic structure and thermoelectric properties of Zn-doped SnTe using the Korringa-Kohn-Rostoker method within the coherent potential approximation, complemented by pseudopotential calculations. SnTe is a lead-free analogue of PbTe and a candidate thermoelectric material in which Zn doping has been experimentally reported to enhance the performance of $p$-type samples. We show that Zn introduces a resonant-like impurity state, located within the conduction band, which evolves strongly depending on the Zn concentration. This feature leads to a significant enhancement of the thermopower in $n$-type SnTe. In the valence band, Zn doping induces L-$Σ$ band convergence, also resulting in an increased $p$-type Seebeck coefficient over a broad concentration range and delaying the onset of the bipolar effect. We further demonstrate that the Zn-induced band-structure modifications drive a transition from an inverted to a trivial band ordering, indicating a controllable topological phase transition. Our results clarify the microscopic role of Zn in SnTe and identify doping as a mechanism for simultaneously tuning thermoelectric and topological properties.

Source: Physical review. B./Physical review. B

DOI: 10.1103/sy2c-ggdb

Authors: Kacper Pryga, Bartlomiej Wiendlocha

Institution: AGH University of Krakow

Language: English

Topic: Advanced Thermoelectric Materials and Devices

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: green

Funders: Akademia Górniczo-Hutnicza im. Stanislawa Staszica, Infrastruktura PL-Grid, Academic Computer Centre Cyfronet, AGH University of Science and Technology

Award: G9001107444