Structural Design And Performance Simulation Of Graphene/silicon Composite

Silicon is abundant in nature,and its extraction process is mature.Silicon-based devices have the characteristics of long life and stable performance.Silicon-based materials are widely used in the electronic information and new energy industries.They are the core materials for independent innovation,development,transformation,and upgrading in integrated circuits and new energy industries.The hardness and brittleness of silicon-based materials,which are prone to defects during processing,limit their high-level applications.Adding graphene as a reinforcing phase to siliconbased materials will closely bond with the matrix interface,improving the mechanical properties of the composite.On the other hand,the performance of silicon-based devices is also related to the surface finish of silicon wafers.Using graphene as a solid lubricant in material processing is expected to yield products with high surface quality.Due to the limitations of experimental conditions,it is challenging to observe and study the mechanical behavior and processing damage of graphene/silicon composites at the atomic level.This paper uses molecular dynamics simulation to study graphene/silicon composites.Firstly,composite material models with different graphene arrangements were designed,and the mechanical properties of the composites under dispersed and stacked graphene arrangements were studied.It was found that the mechanical properties under distributed arrangements were better.The strain rate has little effect on the peak stress of the composite,but its impact on the failure strain and Young’s modulus is relatively complex.The temperature has a significant effect on the mechanical properties of the composite.As temperature increases,its failure strain,peak stress,and Young’s modulus all decrease.Secondly,a scratch model of a graphene-coated silicon workpiece was constructed,and a pure silicon model was built as a control group.Different scratch speeds and depths were set for simulation.It is found that compared to pure silicon scratches,graphene coating on the surface of the silicon workpiece has an inhibitory effect on the movement of atoms in the workpiece during the scratch process,and the chips almost do not accumulate in front of the abrasive.Increasing abrasive scratch speed and scratch depth will deepen the depth of defect atoms in phase transformation,but graphene at 2 nm depth is more prone to fracture failure.Finally,the effect of different initial temperatures on the scratch damage of a graphene-coated crystalline silicon was studied.Research has found that an increase in initial temperature will make the damaged area sharper after indentation,and the workpiece’s surface,after scratching,will become rougher.For graphene,as long as graphene does not break,its inhibiting effect will always exist,and the chip rarely accumulates in front of the abrasive.After stretching the scratched workpiece,it was found that the initial processing temperature also affects the post-processing of the silicon workpiece.In this thesis,a model of graphene/silicon composite material was established and simulated.The effects of graphene as a reinforcing phase and coating material on the mechanical properties of silicon were studied at the nanoscale.The research results provide guidance for the design and processing of such composite materials and ultimately improve the application level of devices.