Analysis Of Graphene Nano-cutting Process And Edge Topography Formation Mechanism

As a two-dimensional nanomaterial,graphene has excellent physical properties and important applications in many aspects.At the same time,graphene is also expected to replace silicon-based materials as a new generation of semiconductor materials.However,the zero band gap feature of graphene becomes the biggest obstacle to its application in the semiconductor field.The band gap can be opened by processing graphene into nanoribbons with a limited width in the lateral direction.Therefore,it is very necessary to find a processing method that is efficient and simple to guarantee the processing quality.The current processing methods to open the gap of graphene mainly include nanoparticle etching,energy beam processing,and AFM mechanical scribing.Each of these processing methods has some drawbacks.By comparing various methods,it can be seen that the AFM mechanical scribing method is controllable,but it is difficult to guarantee the processing quality.Therefore,improving quality is the key point to realize the processing of graphene nanoribbons by the AFM mechanical dicing method.Therefore,this study first uses LAMMPS software to establish a simulation model of diamond probe scribing graphene,and then simulate the scribing process to explore the influence of different cutting parameters on the scribing.The main research contents of this study list as follows:(1)The study analyzes and selects appropriate simulation conditions,such as boundary conditions,ensemble,and time step.It can ensure the stability of the system during the simulation process.At the same time,the interaction relationship between the particles is analyzed and the corresponding potential functions are selected respectively to ensure the accuracy of the simulation results.(2)The simulation first relax the system to minimize the energy of the system,so that the model is in the most stable state.Then by changing the depth of the probe penetration,the cutting speed of the probe and the starting temperature of the environment are investigated to explore its influence on the cutting process.After analyzing and summarizing the simulation results,it can be seen that the deeper the penetration depth of the probe,the greater the cutting force of the probe on the graphene,and the easier it is to form a complete scratch;the lower the cutting speed of the probe,The distribution of cutting force is more uniform,and the morphology of the formed scratches is more regular;the higher the temperature of the environment,the faster the speed of molecular movement,and the easier the carbon-carbon bond is broken,which is helpful for the formation of scratches.(3)The study analyzes and summarizes the special structure in the scratch-shaped edge morphology.It shows that the special structures that often appear during the dicing process include carbon chains,multi-element rings,transverse cracks,and graphene clusters.Later,the formation mechanism of these structures was analyzed one by one from the perspective of mechanics and chemistry.(4)Finally,the graphene sample was cut by a nano-scratch instrument and an atomic force microscope and compared with the simulation results...