On the dual character of Zn impurity in SnTe: Tuning thermoelectric and topological properties

Kacper Pryga; Bartlomiej Wiendlocha

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arXiv · 2609.24459

On the dual character of Zn impurity in SnTe: Tuning thermoelectric and topological properties

Kacper Pryga·Bartlomiej Wiendlocha

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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.

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Kacper Pryga, Bartlomiej Wiendlocha. 2026-09-21. On the dual character of Zn impurity in SnTe: Tuning thermoelectric and topological properties. https://arxiv.org/abs/2609.24459

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