石墨烯与GaN材料的接触研究

	石墨烯与GaN材料的接触研究
其他题名	Research on the contact of Graphene and GaNmaterials
	徐昌一
学位类型	硕士
导师	黎大兵
	2015-11
学位授予单位	中国科学院大学
学位专业	凝聚态物理
关键词	石墨烯 Gan 探测器 Mocvd 肖特基接触
摘要	石墨烯具有优异的光学、电学、机械等特性，被视为新型材料的突破口； GaN 基材料具有直接宽禁带、热稳定性强、高功率等性质，已经成为“继硅之后最重要的半导体材料”。如何将石墨烯与GaN 基宽禁带半导体材料相结合，发挥两种材料体系的优势，将为光电子、微电子器件的发展带来新的契机。目前，关于石墨烯与GaN 基材料相结合的研究处于起步阶段，虽然已有报道利用石墨烯做电极来提高GaN 基LED 的发光效率，但是，在石墨烯与GaN 相结合方面，仍存在诸多需要解决的问题，例如目前，通常利用转移的方式，将生长在Cu 衬底上的石墨烯转移到GaN 基材料上，操作困难且石墨烯的尺寸与转移位置精度难以控制，如何实现操作简单、精度可控的石墨烯与GaN 接触尚有待解决。此外，如何实现石墨烯与GaN 材料形成不同的接触类型，即如何形成Graphene/GaN 肖特基接触，如何形成Graphene/GaN 欧姆接触，其内在控制机理尚没有被阐明。本论文以“石墨烯与GaN 基材料的接触”为主要研究内容，重点研究了石墨烯与GaN 基材料之间的接触行为，获得了操作简单、重复性好的石墨烯/GaN 形成良好接触的工艺方法，阐明了影响石墨烯/GaN 接触类型的物理机理，并在此基础上，成功研制了石墨烯/GaN 紫外-近红外双色探测器，为石墨烯/GaN 基材料相结合的光电子器件和微电子器件的进一步发展和应用奠定了基础。本课题主要研究的内容如下： 1）石墨烯与GaN 材料的接触工艺研究，重点研究如何实现工艺简单、石墨烯尺寸可控、重复性高的石墨烯/GaN 接触；2）石墨烯与GaN 材料接触的物理机理研究，重点研究影响石墨烯/GaN 接触类型的机理，研究形成欧姆或肖特基接触的条件； 3）石墨烯与GaN 接触的光学、电学性能的研究，并成功研制石墨烯/GaN 紫外-近红外探测器本论文的创新点如下： 1）首次成功利用液态石墨烯实现石墨烯与GaN 基材料的接触，通过滴定法和旋涂法将石墨烯覆盖在GaN 表面，形成良好的石墨烯/GaN 接触。与传统的通过转移生长在Cu 衬底上的石墨烯相比，本方法工艺简单、重复性高、可控性好。 2）成功研制石墨烯/GaN 紫外-近红外双色探测器，响应波长分别为350nm 和800nm 和870nm, 研究了石墨烯褶皱的数量差异以及边缘形状的不同对接触行为的影响，发现，石墨烯的褶皱和石墨烯边缘形状可以调节石墨烯/GaN 接触后的电学性质，石墨烯的褶皱可以作为石墨烯片状结构之间的导电通道，改善液态石墨烯层间导电性差的缺点。此外，石墨烯褶皱的形状影响石墨烯/GaN 接触后GaN 空间电荷区的宽度，提高肖特基势垒高度，进而提高石墨烯/GaN 探测器的光响应特性。
其他摘要	Due to its special structure, Graphene has very good optical, electrical, mechanical and other properties and it is regarded as a breakthrough of the new materials. Thanks to the wide band gap, thermal stability, high working power and other properties, GaN materials have become the "most important, after the silicon semiconductor material." It will bring great benefits for the photoelectric and microelectric devices if we can successfully combine the graphene with GaN materials. At present, it has been reported that graphene electrodes are used to improve the luminous efficiency of GaN-based LED. However, there are still some problems should be solved, such as the transfer process. The graphene was usually transferred from the Cu substrate by etching process, which is very hard to control the transferring process and limite the use of graphene into the GaN material. Furthermore, the physician mechanism of the contact of graphene and graphene is unclear. In this paper, we studied the contact of the graphene and GaN material, mainly focus on the physical mechanism and the contact behavior between graphene and GaN. . The main contents of this paper are as follows: 1) The research of the contact behavior between graphene and GaN materials, focusing on how to form good contact between graphene and GaN material by simple and repeatable method. 2) The investigation of l mechanism of the contact property when graphene and GaN has being contact, focusing on the forming conditions and the physical mechanism of the good ohmic or Schottky contact. 3) Research on optical, electrical and mechanical properties of graphene and GaN contact and graphene/GaN dual detectors were fabricated. The originals in this paper are as follows: 1) Using the liquid graphene instead of conventional graphene grown by CVD on Cu substrate to form the contact of graphene and GaN. Good contact between graphene and GaN were realized through control the quantity method or spinning method using the liquid graphene. Compared with the traditional method of graphene transferred by etching process, the method used here is simple and repeatable. 2) Graphene/GaN detectors were fabricated, which have spectral response both at ultraviolet and near infrared region. The effect of the folds and the different pairs of graphene edge shapes on the contact property were also studied. It shown that the edge shapes and folds adjusted the electrical properties performed after graphene exposured to GaN materials. These folds can be regarded as conductive paths among the sheet-like graphene structures, with the function to improve the shortcomings of poor electronics conducting. Furthermore, the shapes of graphene folds can help to broaden the width of the space charge region and increase the Schottky barrier height in the destination to improve the light response.
语种	中文
文献类型	学位论文
条目标识符	http://ir.ciomp.ac.cn/handle/181722/49227
专题	中科院长春光机所知识产出
推荐引用方式 GB/T 7714	徐昌一. 石墨烯与GaN材料的接触研究[D]. 中国科学院大学,2015.

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