Pentagraphyne: A High-Performance Thermoelectric Material with High Seebeck Coefficient

The growing global demand for energy necessitates the exploration of innovative solutions for efficient energy conversion as a result of which thermoelectric materials have garnered significant attention in recent years. In this study, we theoretically investigate the thermoelectric transport properties of pentagraphyne, a promising two-dimensional material. Utilizing the nonequilibrium Green’s function approach, we analyze key thermoelectric parameters that include the Seebeck coefficient, electrical and thermal conductances (both electronic and phononic), and the thermoelectric figure of merit ( ZT ). Pentagraphyne exhibits an exceptionally ultrahigh Seebeck coefficient at room temperature, surpassing conventional thermoelectric materials and affirming its potential for advanced energy conversion applications. At room temperature, pentagraphyne achieves a thermoelectric figure of merit of ZT = 1.15 at a chemical potential (μ) = −1.74 eV. Remarkably, pentagraphyne maintains 0.60 ≤ ZT ≤ 1.26 over a broad temperature range from 200 to 700 K, demonstrating its suitability for sustainable and efficient energy conversion under varying thermal conditions. Notably, optical phonon modes dominate its lattice thermal transport, contributing 80% at 200 K and increasing to 89% at 700 K, while acoustic contributions decrease from 20% to 11%, respectively. These findings highlight pentagraphyne’s potential as a next-generation thermoelectric material, paving the way for innovative applications in renewable energy technologies.