First-principles prediction of the thermoelectric properties of Sn(S 0.2 Se 0.8 ) alloys
Year: 2026
Type: article
Abstract: Thermoelectric power is an efficient and flexible technology for improving energy efficiency, but widespread applications require cost-effective and sustainable materials with a high figure of merit zT . Alloying is a common strategy for optimising zT , but predicting and understanding its impact on the material properties is made challenging by the structural disorder. In this work, we develop a practical and rigorous approach to predicting the zT of alloys by combining electrical-transport and lattice thermal-conductivity calculations, with approximate models for the electron and phonon scattering, and apply it to study the Sn(S 0.2 Se 0.8 ) alloy. We compare predictions obtained by averaging over the full set of unique configurations in a 32-atom supercell with those obtained from special quasi-random structure (SQS) structures with supercell sizes of up to 256 atoms. We find that a 128-atom SQS model achieves a good balance balance between computational efficiency and realistic predictions of the physical properties. The calculations indicate that Sn(S 0.2 Se 0.8 ) shows comparable performance to the SnSe endpoint but with a modest enhancement to the zT due to a reduction in the lattice thermal conductivity, which has a particularly significant impact on the low-temperature performance.
DOI: 10.1039/d6cp02931k
Institution: University of Manchester
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: hybrid
OpenAlex ID: W7170594551