The mechanical flexibility, electronic structure and carrier mobility of monolayer GeP: A first principles study

Abstract

Inspired by successful exfoliation in experiment, we explore mechanical, electronic and transport properties of GeP monolayer using first-principles calculations. It is found that the cleavage energy of GeP monolayer is ∼0.39 J/m2, verifying it can be feasibly extracted from its bulk form. The calculated stress-strain relation reveals that monolayer GeP can withstand a tensile stress and strain up to 14.88 GPa and 28%, respectively. The band structure calculations indicate the monolayer GeP possesses an indirect band gap ∼2.28 eV, which can be reduced to 0.43 eV and experiences an indirect-direct transition when axial strain is applied. Besides, the effective masses can be dramatically tuned by strain. The predicted carrier mobilities of GeP monolayer are directionally anisotropic and the electron mobility in x direction exhibits high carrier mobility up to 1242.09 cm2V−1S−1. Therefore, GeP monolayer has great potential for applications in high performance flexible field-effect transistors and optoelectronic devices.