Simulation And Experimental Study Of GaN Nanowires Growth By PVT

GaN nanowires have many excellent properties,such as wide forbidden band width,small dielectric constant.In recent years,it has gradually become a research hotspot.In this paper,the conditions that affect the growth of GaN nanowires by PVT method are discussed.A set of parameters for the growth of nanowires of PVT system is obtained by computational fluid dynamics method.Then,the flow field distribution in the reaction chamber and the consistency of the two and three dimensional geometric model are discussed.Finally,the optical properties of GaN nanowires grown in the laboratory environment are analyzed.Based on the two-dimensional geometric model,the simulation is carried out.By changing the position of the substrate,the flow rate of NH3 and the reaction temperature,multiple GaN nanowires growth data are obtained.The optimal parameters of each group of data are determined by the analysis of the molar concentration of the reactants on the substrate surface and the relative homogeneity of the GaN nanowires.It is found that the GaN nanowires on the substrate can grow well when the substrate distance is 20 mm and the NH3 is 200 sccm and the reaction temperature is 1050?.In order to analyze the abortion distribution in the reaction chamber,the simulation was carried out on the basis of the three-dimensional geometric model.The flow field distribution in three sections is obtained,and the flow and vortex of air flow in different directions are discussed.The nanowires were grown on graphene substrates by PVT method.The SEM images of the samples were analyzed.The results showed that the growth of GaN nanowires was more suitable for GaN nanowires in the laboratory environment.Then the optical properties of the samples were compared and analyzed.Then,the twodimensional geometric model and the three-dimensional geometric model of GaN nanowire deposition rate distribution are compared,the consistency of the model is discussed,and the rationality of the two-dimensional simulation results is proved.The experiments of growing GaN nanowires on graphene substrates are carried out by PVT method.By analyzing the SEM mapping of the samples,it is found that 1100? is suitable for the growth of GaN nanowires in a laboratory environment.Then the optical properties of the samples are compared and analyzed.In this paper,the optimal growth parameters of GaN nanowires grown by PVT method,the distribution of flow field in the reaction chamber and the consistency of two-dimensional three-dimensional model are studied.Then the optical properties of the GaN nanowires grown in the laboratory environment are analyzed.This paper provides an effective reference for the growth of GaN nanowires by PVT method and the analysis of nanowires orientation and morphology.