【摘要】 在6H-SiC(0001)衬底上,通过辅助C束流在不同退火温度下生长石墨烯,并通过原位反射式高能电子衍射、拉曼光谱、近边X射线吸收精细结构谱和原子力显微镜等实验技术对生长的薄膜进行结构表征。实验结果表明:辅助C束流能够降低SiC表面石墨烯的形成温度,在退火温度800℃时就能够形成石墨烯。随着退火温度的升高,石墨烯的晶体质量也逐渐提高。在退火温度达到1300℃时,辅助C束流对在6H-SiC上生长石墨烯的晶体质量具有明显的改善作用。本文认为在高衬底温度下,沉积的C原子能与SiC表面剩余的C原子相结合,沿着存在较强相互作用的界面形成稳定有序的石墨烯片层。更多还原

【Abstract】 Graphene layerswere deposited with a lab-built solid-source molecular beam expitaxy(SS-MBE)reactor, and in-situ monitored by reflection high energy diffraction(RHEED),on 6H-SiC(0001)substrate.The as-deposited graphene was in-situ annealed while carbonwas deposited at a slow rate.The impacts of the growth conditions,especially the assistance of C-deposition in annealing and annealing temperature,on the microstructures were studied.The graphenewas characterized with RHEED,Raman spectroscopy,near-edge X-ray absorption fine structure(NEXAFS),and atomic force microscope.The results show that slow deposition of carbon in annealing significantly improves the microstructures and reduces graphene formation temperature.With the assistance of carbon beam,continuous growth of graphene was observed at an annealing temperature of 800℃; and annealed at 1300℃,high quality graphene was synthesized.Possible mechanism could be thata high annealing temperature increased the numberofC’s dangling bond inSiC substrate,which easily reacted with incident C atoms to form highly-ordered graphene.更多还原