【作者】 王强； 单晓晔； 卞鑫； 王璐； 王鑫艳；

【Author】 Qiang Wang;Xiaoye Shan;Xin Bian;Lu Wang;Xinyan Wang;College of Chemistry and Molecular Engineering,Nanjing Tech University;

【机构】 南京工业大学化学与分子工程学院；

【摘要】 石墨烯与SiC衬底的界面性质和相互作用对石墨烯的可控外延生长具有非常重要的意义。我们的计算模拟结果显示石墨烯与SiC的界面层形成了C-Si或C-C共轭键,从而导致相当大的结构重组。石墨烯底层与碳面虽然形成了强的C-C键,但吸附能却低于石墨烯底层与硅面的吸附能。而石墨烯第二层和底层的吸附能在碳面上明显大于其在硅面的吸附能。石墨烯底层在硅面表现为金属性,而在碳面上为半导体性质。比较Si、C原子与这些界面及表面的相互作用,结果显示Si原子与硅、碳面的吸附能均大于C原子与硅、碳面的吸附能。且Si、C原子与硅面的吸附能均大于各自与碳面的吸附能。更重要的是,一旦SiC的表面覆盖一层石墨烯后,C原子更倾向停留在石墨烯与SiC的界面之间,从而有利于形成新的石墨烯片层,而Si原子更倾向迁移出石墨烯与SiC的界面,吸附于石墨烯的表面上,从而有利于Si原子的进一步热解析。这些发现为石墨烯在SiC衬底上的可控外延生长提供了更深层次的理解更多还原

【Abstract】 It is important to understand the interface and interaction between graphene layers and Si C surfaces. The results show the interfaces have a major reconstruction due to strong interaction of C-Si/C-C bonds. The interaction energy of bottom layer with C-face is significantly lower than that with Si-face, though there are stronger C-C bonds. The interaction energy of graphene second and bottom layers on C-face is higher than that on Si-face. Compared with Si and C atoms, Si has a stronger interaction with both Si-and C-face than C. The interactions of Si and C atoms with Si-face are stronger than that with C-face. Importantly, once Si C surfaces are covered by first carbon layer, C prefers to stay on the interface rather than on surface of existing carbon layer. In contrast, Si only prefers staying on the surface of existing carbon layer, not staying on the interface. The findings provide insight into the growth of graphene on SiC substrate.更多还原