金刚石上石墨烯的自组织生长与电学特性研究

Graphene is a monolayer of carbon atoms tightly packed into a flat two-dimensional (2D) honeycomb lattice. Since successfully fabricated in 2004, graphene has drawn great interest because of its good thermal conductivity, mechanical stiffness, and extraordinary electronic transport properties as well as its potential applications in high-speed, ballistic-transport-based electronic devices, and so on. However, the substrates can intensively influence the properties of graphene as well as its applications. Consequently, the studies on graphene fabricated on different substrates are needed for expanding its applications.Diamond also has unique mechanical, thermal and electronic properties. Therefore, graphene on diamond could possibly behave novel mechanical, thermal and electronic properties. Further more, the interaction between graphene and the diamond substrate could also result in unpredicted phenomenon. However, up to now, graphene on diamond surface is seldom studied even though the lattice mismatch of diamond (111) surface and graphene /graphite is very small (less than 3%).In this project will study systematically the effects of B-doped concentration and microstructure for diamond (111) facet on self-assembly growth and electric properties of graphene based on our experiences on B-doped diamond synthesis and theory caculation. By controlling the deposition parameters, B-doped diamond (111) facet with various impurity concentrations, grain boundary structures and orientation will be prepared, variety of structures considering doping depth and concentration of boron atoms are investigated, among which the most efficient way to spontaneously form graphene will be found. Further more the physical origin of this phase transition from diamond to graphene will be discussion.This study will provide a new approach to synthesize graphene and graphene-based devices, and is expected to expand the properties and application areas of graphene.

石墨烯与金刚石都是集多种优异的力、光、电和热学等性能于一身的碳材料，在信息、能源和生物等领域具有重要的应用价值。在金刚石衬底上制备石墨烯，有利于结合两者的优势，将石墨烯的多种新奇物理性质呈现出来，并发现二者结合所可能导致的材料新特性，为研制高性能的石墨烯纳电子器件奠定基础。但人们在这一方面的研究一直没有突破。本项目以我们长期在金刚石膜制备、电学性质测量和第一性原理的理论模拟等方面的研究为基础，结合近期在石墨烯生长与物性研究方面的工作，系统地开展硼掺杂金刚石（111）面上石墨烯自组织生长与电学特性研究。通过控制生长条件，实现不同的硼掺杂浓度与梯度分布，以及不同晶体结构的金刚石上石墨烯的制备，研究这些因素对金刚石（111）面衬底上石墨烯自组织生长的影响规律，并结合第一性原理的理论模拟，探索硼掺杂金刚石（111）面上石墨烯的形成机制与新奇电学特性，发现现有知识水平未能理解和预测的现象。

石墨烯与金刚石都是集多种优异物理与化学性能于一身的碳材料，在信息、能源和生物等领域具有重要的应用价值。在金刚石这样的宽带隙绝缘衬底上制备导电或半导体性质的石墨烯，有利于结合两者的优势，将石墨烯的多种新奇性能在室温下呈现出来，为研制高性能的石墨烯纳电子器件奠定基础。但人们在金刚石衬底上直接生长大面积、高质量的石墨烯一直面临挑战。本项目以我们长期在金刚石膜制备、电学性质测量和第一性原理的理论模拟等方面的研究为基础，结合我们在石墨烯生长与物性研究方面的工作，系统地开展了硼掺杂金刚石（111）面上石墨烯自组织生长与电学特性研究。通过控制生长条件，包括硼掺杂浓度与梯度分布，以及不同晶体结构的金刚石上石墨烯的形成规律，实现了金刚石衬底上高迁移率、低缺陷和大面积石墨烯的自组织生长。通过研究这些因素对金刚石（111）面衬底上石墨烯自组织生长的影响规律，并结合第一性原理的理论模拟，探索了硼掺杂金刚石（111）面上石墨烯的形成机制与新奇电学特性，发现现有知识水平未能理解和预测的现象，为新型高性能石墨烯器件的研制奠定了基础。