碳化硅衬底外延石墨烯

通过高温热解法和化学气相沉积(CVD)法在SiC(0001)衬底外延石墨烯。采用光学显微镜、原子力显微镜、扫描电子显微镜、喇曼光谱、X射线光电子能谱和霍尔测试系统对样品进行表征,并对比了两种不同生长方法对石墨烯材料的影响以及不同的成核机理。结果表明,高温热解法制备的石墨烯材料有明显的台阶形貌,台阶区域平坦均匀,褶皱少,晶体质量取决于SiC衬底表面原子层,电学特性受衬底影响大,迁移率较低。CVD法制备的石墨烯材料整体均匀,褶皱较多,晶体质量更好。该方法制备的石墨烯薄膜悬浮在SiC衬底表面,与衬底之间为范德华力连接,电学特性受衬底影响小,迁移率较高。

Epitaxial Graphene on SiC Substrates

Graphene was epitaxially grown on SiC(0001) substrates by the high temperature thermal decomposition method and chemical vapor deposition(CVD) method. The samples were characterized by the optic microscope, atomic force microscope, scanning electron microscope, Raman spectroscopy, X-ray photoelectron spectroscopy and Hall test system. The influences of two different growth methods on graphene materials and different nucleation mechanisms were compared. The results show that the graphene material prepared by the high temperature thermal decomposition method has ob-vious step morphology with a flat and uniform step region and a few wrinkles. The crystal quality depends on the atomic layers on the surface of SiC substrates. The electrical properties are greatly affected by the substrate and the mobility is low. The graphene material prepared by the CVD method has a uniform ove-rall shape with more wrinkles and better crystal quality. The graphene film prepared by the CVD method is suspended on the surface of the SiC substrate, which is connected with the substrate by van der Waals force, and the electrical properties are less affected by the substrate and the mobility is higher.