光电弹道电子发射显微术对石墨烯与III-族氮化物半导体界面局域光电性质的研究

项目名称： 光电弹道电子发射显微术对石墨烯与III-族氮化物半导体界面局域光电性质的研究

项目编号： No.11204347

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 物理学I

项目作者： 徐耿钊

作者单位： 中国科学院苏州纳米技术与纳米仿生研究所

项目金额： 28万元

中文摘要： 石墨烯具有特殊的与其微观结构密切相关的相对论性费米子能带结构，且其载流子浓度高度可调。因此，它与半导体相接触的界面性质将迥异于传统的金属-半导体接触。这种新材料的引入极有可能引起器件结构和性能的革命性变化。然而目前，对这样一种新型界面上的电子结构、载流子输运以及光电相互作用尚缺乏深入的研究，而常规光电表征手段难以从微纳尺度上有效了解相关物理机制。本项目拟针对该问题应用自主研发的扫描光电弹道电子发射显微术，以石墨烯与III-族氮化物半导体的界面为研究对象，通过探测针尖注入的载流子在界面上的散射及其对光照的响应，表征石墨烯-半导体的局域界面电子态、势垒高度和光生载流子的输运。结合第一性原理计算，分析石墨烯独特的能带结构对石墨烯与半导体界面接触势垒自适应地进行调控的机制，及其对石墨烯空间微观结构的依赖关系，为设计低功耗、高效率的新颖器件结构提供实验和理论的基础。

中文关键词： 原子力显微镜；石墨烯；半导体；拉曼光谱；界面势垒

英文摘要： Graphene possesses a unique electronic band structure of relativstic-like fermions, which is also affected by its nanostructures greatly. Its carrier concentration is highly tunable as well. Therefor, the contact properties at the interfaces between graphene and semiconductors are quite different from that of traditional metal-semiconductor contacts. This may lead to a huge change in device structures and performances. However, the electronic structure, carrier transport and photo-electronic interactions at these new interfaces still lack intensive study. It is difficult to investigate these interfacial properties in micro or nanometer scale with conventional optoeletronic characterization methods. In view of this problem, taking the interface between graphene and III-nitride as a typical object of study, we propose to investigate the interfacial states, barrier heights and light-induced carrier transport by measuring the scattering of tip-injected carriers at the interfaces and corrcsponding light-induced effects with a homemade photo-assisted ballistic electron emission microscope. Incorporating with first principle calculations, the dependence of self-adaptive mechanism of the cantact barrier between graphene and semiconductor on their energy band structure will be analyzed, as well as on the nanostructures o

英文关键词： atomic force microscope；graphene；semiconductor；Raman spectroscopy；interface barrier