Theoretical prediction of intrinsic electron mobility of monolayer InSe: first-principles calculation

Recently, a novel two-dimensional (2D) semiconductor, InSe, has attracted great attention due to its potential applications in optoelectronic devices and field effect transistors. In this study, phonon-limited mobility is investigated by the first-principles calculation. At 300 K, the intrinsic electron mobilities calculated from the electron?phonon coupling (EPC) matrix element are as high as (zigzag direction) and (Armchair direction), respectively. The deformation potential theory (DPT) based on longitudinal acoustic and optical phonon scattering is also employed to investigate electron mobility. The mobility from optical phonon scattering is much higher than that from longitudinal acoustic phonon scattering. If the polarization characteristics of InSe are not considered, the electron mobility calculated from EPC matrix element is closed to that from the longitudinal acoustic phonon DPT. In this study, we have also investigated the effect of polarization properties in 2D InSe on electron mobility. At 300 K, the electron mobility for including Fr;hlich interaction is reduced to and . Therefore, the electron mobility for InSe is controlled by the scattering from polar phonons. The mobility can be increased to and under 4% biaxial strain. This result is compared with the experiment, and some disagreements are explained.