Study On The Growth System Of Metallic Films In Graphene Layer

With the development of nanotechnology, the products of artificial nanometer materials can be seen everywhere in our daily life, however it also cannot meet the growing needs of people.However, graphene with superior performance has attracted people’s attention, which has injected new blood into the field of nanometer materials. At present, graphene is used as a substrate to prepare heterogeneous films, especially for the thin film hybrid of precious metal and graphene, which can improve the performance of precious metals by some properties of graphene, and meet some special needs of people. Development of thin film preparation technology need the control requirements of the thin film technology continuously improved.Microscopic atomic kinetics is the key to prepare high quality film. The study microscopic atomic dynamics process is key to the preparation of high quality thin films, therefore, it is very important to study the growth mechanism of precious metal thin films on graphene substrate by simulating growth process of microscopic particle on the computer.This paper studied the micro growth model of the Au atoms on the graphene monolayer. We established a two-dimensional substrate model in line with periodic boundary conditions by MATLAB tools, and the Deposition Diffusion Aggregation(DDA) theory was introduced into the model. We simulated the process of film formation with the Kinetics Monte Carlo(KMC)method which is based on the Transition State Theory(TST). And then we proposed the energy calculation methods between different particles, optimized control algorithm, established the morphology evolution of gold films on single layer graphene. So the characteristic parameters of atomic islands could be analyzed statistically. And the relationship between grain growth and control conditions was established, and the evolution trend of grain growth and two-dimensional surface morphology was realized.By simulating surface evolution of Au film, this paper discussed the particle adsorption,diffusion, nucleation, the desorption process, explained the particle number, growth time,solution concentration corresponding to the deposition rate, the transition state barrier, and different desorption probability so on. The results showed that the solution concentration was one of the external control conditions for Au film formation. Controlling the parameter could control the growth trend of the atomic clusters on the substrate. When the concentration was lower, the cluster size was smaller and uniform distribution, there was enough time and space to find its stable states. When the concentration was larger, the deposition particles did not have enough time and space to find its metastable position, so easily leading to fractal growth.Considered separately the desorption probability effect the configuration of the system. It wasconcluded that, during the process of simulation, appropriately reducing the desorption rate had a great effect on improving the quality of the film formation. Other parameters also influenced the configuration of the system. As long as you could control the external conditions well, it could be prepared less defect, high performance, large area of hybrid film with high quality.In short, the two-dimensional model constructed in this paper could qualitatively explain the evolution process of the morphology on the substrate, simplified the process of the preparation of the thin film, and had a certain guiding role for the grain growth of other materials. However, in the simulation process, since the time of the event execution was assumed to be equal to the arrival time of the next atom, it also needs to improve the model if we want to get an accurate explanation of mechanism of the film growth and evolution.