First-principles study on electronic and thermoelectric properties of Janus monolayers AsXC3 (X: Sb, Bi)

Abstract

Janus structure as novel two-dimensional materials has received great interest owing to their novel properties. By using first-principles calculations, we investigated the electronic structure and thermoelectric properties of the As2C3 monolayer and Janus AsBiC3 and AsSbC3 structures. The results showed that the dynamical stability of the three structures has been confirmed by phonon dispersion curves. The effect of temperature and chemical potential on transport parameters such as Seebeck coefficient, electronic figure of merit, electrical and electronic thermal conductivities have been comprehensively discussed. The results show that the predicted Janus structures AsBiC3 and AsSbC3 can achieve the same enhancement in electrical (σ/τ) and electronic thermal conductivities (ke/τ). Interestingly, it is found that the calculated electronic figure of merit ZTe is 0.73 at 300 K for Janus structure AsBiC3, and ZTe of 0.99 and 0.95 at 300 K and 700 K, respectively, for Janus structure AsSbC3. The calculated properties for Janus AsBiC3 and AsSbC3 structures show that these studied materials are promising candidates for future application in thermoelectric.