Institute for Materials Chemistry and Engineering Kyushu University Kasuga, Fukuoka 816-8580, Japan.
Small. 2010 Jun 6;6(11):1226-33. doi: 10.1002/smll.200902405.
Rectangle- and triangle-shaped microscale graphene films are grown on epitaxial Co films deposited on single-crystal MgO substrates with (001) and (111) planes, respectively. A thin film of Co or Ni metal is epitaxially deposited on a MgO substrate by sputtering while heating the substrate. Thermal decomposition of polystyrene over this epitaxial metal film in vacuum gives rectangular or triangular pit structures whose orientation and shape are strongly dependent on the crystallographic orientation of the MgO substrate. Raman mapping measurements indicate preferential formation of few-layer graphene films inside these pits. The rectangular graphene films are transferred onto a SiO(2)/Si substrate while maintaining the original shape and field-effect transistors are fabricated using the transferred films. These findings on the formation of rectangular/triangular graphene give new insights on the formation mechanism of graphene and can be applied for more advanced/controlled graphene growth.
矩形和三角形微尺度石墨烯薄膜生长在分别具有（001）和（111）面的外延 Co 薄膜上。通过溅射在 MgO 衬底上外延沉积一层 Co 或 Ni 金属薄膜，同时加热衬底。在真空中外延金属薄膜上的聚苯乙烯热分解会产生具有特定取向和形状的矩形或三角形坑结构，这些结构强烈依赖于 MgO 衬底的结晶取向。拉曼映射测量表明，在这些坑内优先形成少层石墨烯薄膜。矩形石墨烯薄膜在保持原始形状的情况下转移到 SiO2/Si 衬底上，然后使用转移的薄膜制造场效应晶体管。这些关于矩形/三角形石墨烯形成的发现为石墨烯的形成机制提供了新的见解，并可应用于更先进/可控的石墨烯生长。
