High switching ratio and inorganic gas sensing performance in BeNbased nanodevice: a first-principles study.

Recently, Dirac material BeNhas been synthesized by using laser-heated diamond anvil-groove technology (Bykov2021175501). BeNlayer, i.e. beryllonitrene, represents a qualitatively class of two-dimensional (2D) materials that can be built of a metal atom and polymeric nitrogen chains, and hosts anisotropic Dirac fermions. Enlighten by this discovered material, we study the electronic structure, anisotropic transport properties and gas sensitivity of 2D BeNusing the density functional theory combined with non-equilibrium Green's function method. The results manifest that the 2D BeNshows a typical semi-metallic property. The electronic transport properties of the intrinsic BeNdevices show a strong anisotropic behavior since electrons transmitting along the armchair direction is much easier than that along the zigzag direction. It directly results in an obvious switching characteristic with the switching ratio up to 10. Then the adsorption characteristics indicate that HS, CO, COand Hmolecules are physisorption, while the NH, NO, NO, SOmolecules are chemisorption. Among these chemisorption cases, the 2D gas sensor devices show an extremely high response for SOrecognition, and the high anisotropy of the original 2D BeNdevice still maintains after adsorbing gas molecules. Finally, high switching ratio and inorganic gas sensing performance of BeNmonolayer could be clearly understood with local density of states, bias-dependent spectra, scattered state distribution. In general, the results indicate that the designed BeNdevices have potential practical application in high-ratio switching devices and high gas-sensing molecular devices.