Mechanical Properties Of Phosphorene Noble Metal Doping System And Application

As a new type of semiconductor material,the two-dimensional phosphorene not only has the direct band gap which the graphene lacks,but also has excellent performance,such as high carrier mobility,on/off ratio and so on.In order to make the properties of phosphorene widely used,it is inevitable to improve its performance by adsorption and chemical modification.But most of the researchers focused on the functionality after doping.Few people considered the effect of doping on the mechanical properties of phosphorene.At present,the research on mechanical properties of phosphorene is only limited to perfect construction and artificial structure defects.In this paper,based on the first principle density functional theory,we use three kinds of noble metal atoms,gold,silver and platinum,to dope the structure of phosphorene.And the simulation of the mechanical properties of the defective phosphorene by doping is carried out.First,we optimize the doping structure by the first principle and calculate the energy transfer.It is observed that the defects of geometry structure caused by doping and the stability of the system is analyzed.Next,at the 300K temperature,we use molecular dynamics based on the first principles to relax the doped system to determine whether the structure at room temperature is stable.Then,in order to investigate the tensile strength and fracture mode of the doped structure,we carried out uniaxial tension in zigzag direction and armchair direction.By fitting strain energy curve,the young's modulus and Poisson's ratio of the doped structure are calculated,and how the doping defects influent the mechanical properties of the whole structures are discussed.Then,we use the first principle to calculate the doped structures' band structure and density of state,so as to analyze the effect of strain on the band gap and other electrical properties of the doped structure.In addition to the above research work,we also study the adsorption characteristics of the doped system.We adsorb NO and CO molecules on the surface of pristine phosphorene and doped structures,and then determine the adsorption effect by calculating the adsorption energy.At the same time,we also explore the gas sensitivity of doped structure by calculating the electrical properties of the base system after gas adsorption.