中文摘要：

石墨烯的形核和生长动力学过程的控制对于单晶石墨烯的制备有着至关重要的影响。采用低压化学气相沉积（CVD）方法,通过优化生长条件参数,在铜箔衬底上生长出4mm左右的大尺寸单晶石墨烯。通过一系列形貌和结构的表征,证明了样品为高质量的单层单晶石墨烯。同时观察到CVD生长的亚毫米级、A-B型堆垛的多层单晶石墨烯畴,以及由单晶石墨烯共生形成的叠层结构。此外通过采用3种类型的铜箔衬底生长石墨烯,发现铜箔特性如体氧含量等对石墨烯成核密度和单晶石墨烯形貌有重要的影响,并观察到不同类型铜箔的晶面择优取向在CVD生长前后发生不同的转变。最后,利用所生长的大尺度单晶石墨烯制备场效应晶体管,实现高的载流子迁移率。

英文摘要：

The effective controlling of the graphene nucleation and growth kinetics is critical to grow single crystal graphene.In this paper,single crystalline graphene with a large size of 4 mm was achieved via the optimization of the processing parameters of low pressure chemical vapor deposition（CVD）.The graphene samples are proved to be high quality single-layer graphene,inspected by a series of structural and morphological characterizations.Furthermore,the sub-millimeter size multi-layer single crystal graphene with A-B stacking,as well as the overlapped layer structure formed by two converged graphene domains was observed.It is also found that the properties of the Cu substrates such as its bulk oxygen content play a significant role on nucleation density and morphology of single crystal graphene,by utilizing three types of copper foil substrates for the CVD process.Surface texture of three types of the Cu foils also exhibit different transition behavior after the CVD process.Finally,the field effect transistors based on the as-deposited large-size single crystal graphene have been fabricated,displaying high carrier mobility.