Strain Dependent Carrier Mobility in 8 − Pmmn Borophene: ab-initio study

Abstract

Recently two dimensional layer of 8-Pmmn borophene has been successfully fabricated on single crystal Ag(111) substrate and shown to have a tilted anisotropic Diraccone. In this paper we investigate the strain dependent carrier mobility in 8 - Pmmn borophene. We calculate the electronic structure, group velocity and carrier mobility of 8 - Pmmn borophene using density functional theory coupled with Boltzmann transport method using constant relaxation time approximation. Our results show that bandstructure anisotropy results in anisotropic group velocity and mobility. The intrinsic group velocity and mobility at room temperature are calculated to be 2. $17 \times 10^{6ms^{-1}}$, 2. $42 \times 10^{6ms^{-1}}$ and 1. $82 \times 10^{6 cm^{2V^{-1s^{-1}}},2.26\times 10^{6 cm^{2V^{-1s^{-1}}}}}$ in $+x, +y$ direction as well as $1.56\times 10^{6ms^{-1}}, 2.43\times 10^{6ms^{-1}}$ and $9.42\times 10^{5} cm^{2}V^{-1}s^{-1}, 2.29\times 10^{6 cm^{2V^{-1s^{-1}}}}$, in - x, - y directions, respectively. Both of them are found to be highest under 1% compressive strain.