Mechanical, optical and thermoelectric properties of Janus BiTeCl monolayer

Abstract

We report mechanical, optical and thermoelectric properties of recently fabricated Janus BiTeCl monolayer using density functional and semi-classical Boltzmann transport theory. Janus BiTeCl monolayer exhibits a direct bandgap, high carrier mobility (∼103 cm2V−1s−1) and high optical absorption in the UV–visible region. The mechanical behavior of the Janus BiTeCl monolayer is nearly isotropic having an ideal tensile strength ∼15 GPa. The higher value of the Gruneisen parameter (γ), a low value of phonon group velocity (vg), and very little phonon scattering time (τp) lead to low lattice thermal conductivity (1.46 W/mK) of Janus BiTeCl monolayer. The combined effect of thermal conductivity and electronic transport coefficients of Janus BiTeCl monolayer results in the figure of merit (ZT) in the range of 0.43–0.75 at 300–500 K. Our results suggest Janus BiTeCl monolayer be a potential candidate for optoelectronic and moderate temperature thermoelectric applications.