Strain-Induced Modulation of Electron Mobility in Single-Layer Transition Metal Dichalcogenides MX₂ (<inline-formula> <tex-math notation="LaTeX">$M = {\rm Mo}$ </tex-math> </inline-formula>, W; <inline-formula> <tex-math notation="LaTeX">$X = {\rm S}$ </tex-math> </inline-formula>, Se)

Abstract

In this paper, the effect of biaxial strain on the mobility of single-layer transition metal dichalcogenides (MoS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> , MoSe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> , WS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> , and WSe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ) is investigated by accounting for the scattering from intrinsic phonon modes, remote phonons, and charged impurities. Ab initio simulations are employed to study a strain-induced effect on the electronic band structure, and the linearized Boltzmann transport equation is used to evaluate the low-field mobility. The results indicate that tensile strain increases the mobility. In particular, a significant increase in the mobility of single-layer MoSe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> and WSe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> with a relatively small tensile strain is observed. Under a compressive strain, however, the mobility exhibits a nonmonotonic behavior. With a relatively small compressive strain, the mobility decreases and then it partially recovers with a further increase in the compressive strain.