The study of chemical vapor deposition graphene growth mechanism based on isotope labelling technique

石墨烯是一种只由单个碳原子层构成的理想二维材料，自2004年首次被Novoselov等人采用胶带法从高定向热解石墨表面剥离出来后，其高电子迁移率，高热导，高硬度，高透光率等一系列独特优异的物理化学性质就不断被揭示，近十几年来一直保持着其研究热点的领先地位，同时还带动了其他二维层状材料的研究热潮。 目前石墨烯主要的制备方法分为以下四类：机械剥离法、氧化还原法、碳化硅外延法和化学气相沉积法；其中化学气相沉积法在生长高质量大面积石墨烯方面表现出很大的优势，尤其是在铜衬底上已获得30英寸的大尺寸单层石墨烯；再加上铜箔本身的低成本、易转移等特点，使得其成为实现石墨烯商业化生产的首要衬底；因此完善化学气...Graphene is an ideal two dimensional material with only one layer carbon atoms. Its unique physical and chemical properties such as high electronic mobility, high thermal conductivity, extreme mechanical hardness and high transparency have been revealed since it was first synthesized using the tape method in 2004. It has been keeping the leading research hotspot in recent years and has also motiva...学位：理学博士院系专业：物理科学与技术学院_凝聚态物理学号：1982012015389

Polymeric amorphous carbon films with an extended range of optical gaps

A new type of hydrogenated amorphous carbon (a-C:H) film is prepared under low bias voltage and an extended range of plasma density in a radio-frequency plasma enhanced chemical vapor deposition system (RF-PECVD). The obtained a-C:H samples are grown on electrically floating substrates instead of substrates mounted on the powered or the grounded electrode of RF-PECVD, and have structure and properties that are significantly different from regular a-C:H films. The samples have an optical gap ranging from 1 to 4 eV, while maintaining low intrinsic stress between 0.1 and 0.2 GPa. Fractions of all types of CH x carbon-hydrogen groups of the obtained samples are measured, analyzed, and used to locate these samples in the carbon-hydrogen ternary phase diagram. The obtained samples are located in the same general area as the regular a-C:H films, indicating configurational rather than compositional structural differences. The hydrogenation ratio of sp3 carbons in the obtained samples is found to remain at a very high level, and is used to explain their unique properties. ? 2013 Elsevier B.V