Crystal symmetry modification enables high-ranged in-plane thermoelectric performance in n-type SnSe crystals.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 39979348.
- Also identified by DOI 10.1038/s41467-025-57125-w and PMC identifier 11842792.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
SnSe crystal has witnessed significant advancements as a promising thermoelectric material over the past decade. Its in-plane direction shows robust mechanical strength for practical thermoelectric applications. Herein, we optimize the in-plane thermoelectric performance of n-type SnSe by crystal symmetry modification. In particular, we find that Te and Mo alloying continuously enhances the crystal symmetry, thereby increasing the carrier mobility to ~ 422 cm<sup>2 </sup>V<sup>-1</sup> s<sup>-1</sup>. Simultaneously, the conduction bands converge with the symmetry modification, further improving the electrical transport. Additionally, the lattice thermal conductivity is limited to ~ 1.1 W m<sup>-1</sup> K<sup>-1</sup> due to the softness of both acoustic and optical branches. Consequently, we achieve a power factor of ~ 28 μW cm<sup>-1</sup> K<sup>-2</sup> and ZT of ~ 0.6 in n-type SnSe at 300 K. The average ZT reaches ~ 0.89 at 300-723 K. The single-leg device based on the obtained n-type SnSe shows a remarkable efficiency of ~ 5.3% under the ΔT of ~ 300 K, which is the highest reported in n-type SnSe. This work demonstrates the substantial potential of SnSe for practical applications of power generation and waste heat recovery.