Ultralow lattice thermal conductivity and high thermoelectric performance of penta-Sb2C monolayer: A first principles study.

In this study, by utilizing the first-principles calculation coupled with the Boltzmann transport theory, we comprehensively study the thermoelectric (TE) properties of the Sb₂C monolayer. The calculated results show that the Sb₂C monolayer owns an inherent ultra-low lattice thermal conductivity of 0.88 W m⁻¹ K⁻¹ at 300 K, which originates from small phonon group velocities, large Grüneisen parameters, and short phonon lifetimes. The Sb₂C monolayer also exhibits excellent electrical transport properties mainly due to the degeneration of the bottom conduction bands, which increases the Seebeck coefficient of the n-type doped samples and thus yields a larger power factor. Based on the extremely low lattice thermal conductivity and superior electrical transport performance, a large ZT value of 2.71 for the n-type doped Sb₂C monolayer at 700 K is obtained. Our results quantify Sb₂C monolayers as promising candidates for building outstanding thermoelectric devices. [ABSTRACT FROM AUTHOR]