摘要
利用化学气相沉积法,在Si衬底、蓝宝石衬底和SiC衬底上生长石墨烯材料,研究石墨烯的表面形貌、缺陷、晶体质量和电学特性。原子力显微镜、光学显微镜和拉曼光谱测试表明,Si_3N_4覆盖层可以有效抑制3CSiC缓冲层的形成;低温生长有利于保持材料表面的平整度,高温生长有利于提高材料的晶体质量。5.08cm蓝宝石衬底上石墨烯材料,室温下非接触Hall测试迁移超过1000cm2·V^(-1)·s^(-1),方块电阻不均匀性为2.6%。相对于Si衬底和蓝宝石衬底,SiC衬底上生长石墨烯材料的表面形态学更好,缺陷更低,晶体质量和电学特性更好,迁移率最高为4900cm2·V^(-1)·s^(-1)。
Since graphene was made by mechanical exfoliation in 2004,it has attracted great interest due to its unique properties.The growth of graphene directly on insulating substrates without catalyst has emerged as a trend for chemical vapor deposition(CVD)-graphene.This growth method offers an advantage in avoiding the post-growth transfer process.So far,many insulating substrates have been used for graphene growth by CVD,such as Si,sapphire,SiC,and other substrates.In this work,Si,sapphire and SiC substrate were chosen for graphene growth.The surface morphology,defects,crystal quality and electronics characteristic of the samples were characterized by atomic force microscopy(AFM),optic microscopy(OM),Raman spectroscopy,and Hall system.AFM and Raman results showed that 3C-SiC layer could be controlled by Si3N4 covered on Si substrate,and 2D-FWHM of material on Si substrate was between 70cm^(-1) and 90cm^(-1),that crystal quality was not as good as material by traditional method.Graphene was grown on a 5.08 cm sapphire substrate,the material surface morphology appeared more flat under the lower growth temperature,while the crystal quality was better under the higher temperature.The carrier mobility is above 1000cm2·V^(-1)·s^(-1) at room temperature.Compared to epitaxial graphene by Si sublimation,CVD-grown graphene on SiC substrate has a more flatsurface morphology,lower defect,better crystal quality,and higher carrier mobility.The highest carrier mobility of CVD-grown graphene on SiC substrate is 4900cm2·V^(-1)·s^(-1) at room temperature.
出处
《化工学报》
EI
CAS
CSCD
北大核心
2017年第S1期276-281,共6页
CIESC Journal
基金
国家自然科学基金项目(61306006
61674131)~~
关键词
石墨烯
绝缘衬底
化学气相沉积
表面
形态学
电学特性
graphene
insulating substrates
chemical vapor deposition
surface
morphology
electronics characteristic