Potoelectric Performance Study On Graphene Grown By CVD

Graphene is a unique crystal structure of 2D materials.Because of its great pervious to light quality and ultra high electron mobility and its like,in the field of photoelectric device and semiconductor has a broad application prospect.In order to give play to the all of excellent properties of graphene,high quality graphene is indispensable.This paper based on CVD method with copper foil as growth substrate,CH₄ as the carbon source,H₂ for reducing gas under low pressure atmosphere to prepare graphene film.Study the quality of the growth graphene substrate and concentration of carbon source in the process of impact on the quality of graphene.The graphene films were characterized by scanning electron microscopy?sem?,Raman spectroscopy methods and so on.Test the light transmittance and film sheet resistance of graphene.Finally choose excellent comprehensive properties of graphene processed into graphene field effect transistance?GFET?.Meanwhile,study its electrical performance,providing with experimental basis for the applications of graphene microelectronic device.?1?Explores the influence of the quality of graphene film growth with the copper substrate before and after annealing.Found that growth of graphene on copper foil after annealing is better than the quality of the annealing before.The continuity and flatness of graphene films are significantly improved.?2?To study the influence of the quality of the graphene film for CH₄ concentration.The study found that,with the increase of CH₄ concentration,film-forming effect of graphene is getting better and better.When the concentration of CH₄ reaches 30 sccm,the growth of graphene for single-layer graphene films,and film uniformity get the best,film defects to minimum.Continue rise to CH₄ concentration begin to produce the area of multilayer graphene,led to the decrease of the quality of the film.?3?Test the samples of graphene film sheet resistance and light transmittance.The results show that,the graphene prepared by the experiments has high light transmittance?92.7%-95.5%?and low sheet resistance?142.2-435.2?/sq?.?4?Adhering version on the surface of high-quality single-layer graphene film by the experiment,use vacuum evaporation to process graphene field effect transistor.Test electrical performance,for example electron mobility and ratio of switch?on/off?and the like.Through analysis of the output characteristic curve and transfer characteristic curve,finding GFET present P type transport properties.Graphene has supreme electron mobility at low pressure,ith the reduction of temperature of graphene Dirac point gradually shift to the left,”on/off” is increasing.