Quasiparticle band structures and thermoelectric transport properties of p-type SnSe

TL;DR

This study employs advanced computational methods to analyze the electronic band structures and thermoelectric properties of p-type SnSe in different phases, revealing insights into its potential for thermoelectric applications.

Contribution

The paper provides detailed quasiparticle band structures and transport property calculations for both low- and high-temperature phases of p-type SnSe, highlighting phase-dependent electronic features.

Findings

Pnma phase has an indirect band gap of 0.829 eV.

Cmcm phase has a direct band gap of 0.464 eV.

Transport coefficients vary with doping and temperature, informing optimal thermoelectric conditions.

Abstract

We used density functional and many-body perturbation theory to calculate the quasiparticle band structures and electronic transport parameters of p-type SnSe both for the low-temperature Pnma and high-temperature Cmcm phases. The Pnma phase has an indirect band gap of 0.829 eV while the Cmcm has a direct band gap of 0.464 eV. Both phases exhibit multiple local band extrema within an energy range comparable to the thermal energy of carriers from the global extrema. We calculated the electronic transport coefficients for single-crystal and polycrystalline materials to understand previous experimental measurements. We also discuss the dependence of the transport coefficients on doping concentration and temperature to identify doping conditions for optimal thermoelectric performance.