First-principles Investigation Of Vacancy Defected Monolayer Arsenic Germanium

Graphene has been successfully prepared and it has tremendous novel properties as a two-dimensional(2D)materials,so people have discovered the potential application of the 2D materials in electromagnetic devices and have been exploring them.Group?-?binary compound crystals,such as monolayer GeAs,is a new 2D materials,which has been synthesized in experiments.Monolayer GeAs has attracted much attention for its good thermal stability,outstanding anisotropy,large bandgap width and strong light absorption.It is easy to control the 2D materials'electrical and magnetic properties because all atoms of 2D materials are exposed to the environment.Designing electronic band structure can make an unprecedented exploration of new physical properties that are not available in natural or synthetic materials.We focus on the electromagnetic properties of pristine and vacancy doped monolayer GeAs.The major contributions in this paper are as follows:1.Study electronic and magnetic properties of pristine monolayer Geas.Monoclinic monolayer GeAs is a direct bandgap semiconductor with a 1.48e V bandgap.The effective mass of the electron is 0.0034m₀.By adding full spin polarization to the system,it is found that intrinsic monolayer GeAs is non-magnetic.2.Study electronic and magnetic properties of Ge and As vacancy defected monolayer Geas.The 1×6 supercell is determined by the structure relaxation first.For monolayer GeAs containing Ge defects,there is no obvious lattice distortion.The most stable Ge vacancy defect system is a direct band gap semiconductor with a 0.17e V band gap and is nonmagnetic.The As vacancy defect can induce magnetism in monolayer GeAs.Moreover,it has the desired half-metal behavior and has a magnetic moment of0.83?B.The conclusion of this paper is that monolayer GeAs is a direct band gap semiconductor,and the band gap is in the visible light range.Defect doping can regulate the 2D GeAs system and optimize its performance with a simple method.Therefore,2D GeAs has great potential to be applied to some optoelectronic or spintronic devices,and its corresponding practical application scope will be expanded.The results will provide some guidance for the design of high performance electronic devices.