氢化和氧化对石墨烯-金属平面结的输运调制

项目名称： 氢化和氧化对石墨烯-金属平面结的输运调制

项目编号： No.11304263

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 数理科学和化学

项目作者： 张春小

作者单位： 湘潭大学

项目金额： 25万元

中文摘要： 石墨烯以其优异的电子性质，在未来微纳电子学领域具有广泛的应用前景。近来，石墨烯在高性能器件，特别是高频电子器件和磁性存储元件等方面的应用前景引起了人们的极大兴趣，为了推进石墨烯在这些电子器件中的实际应用，我们必须解决石墨烯与金属接触这一关键问题。先前的研究已经关注到这一问题，特别是实验工作表明石墨烯与金属接触所形成平面结（石墨烯-金属平面结）的性质因实验条件、周边环境的不同而不同，然而，现有的理论工作很少考虑到实验条件和周边环境的影响。同时，为了提高器件的性能，实验工作已经成功的通过氢化和氧化的方法降低了石墨烯-金属平面结的电阻。因此，本项目将采用第一性原理与非平衡格林函数相结合的方法研究氢化和氧化对石墨烯-金属平面结性能的调制效应，总结石墨烯-金属平面结的功函数和输运性质依赖于氢化（氧化）的浓度、位置的变化规律，揭示相应的物理机制，为提高石墨烯器件性能的相关实验研究提供一定的理论基础。

中文关键词： 金属/石墨烯平面结；接触效应；第一性原理计算；石墨烯同素异构体；输运特性

英文摘要： Graphene is a promising candidate for nanoelectronics in the future because of its unique electronic properties. Recently, the application of graphene in high-performance devices, such as high-frequency graphene-based transistors and magnetic memory, has attracted great interest. In order to achieve extreme speeds in graphene-based transistors, one must address a potentially limiting factor in graphene devices: the metal/graphene contact. It has already caused a growing concern from the previous. In theoretical studies, it is assumed that the graphene/metal interface is pristine. However, this is rarely the case. In particular, the metal/graphene contact resistence measured in the experiment vary from a few hundred to a few thousand ohm*micron, depending on the measurement conditions. Furthermore, the experimental reports have indicated that the contact resistence could be improved by hydrogenation or oxygen plasma treatment. Consequently, the effects of the hydrogenation and oxidation on the transport properties of the metal/graphene planar junction is investigated by the density functional theory in combination with the nonequilibrium Green's function method in this project. Our studies focus on the evolution of work function and transport properties in dependence on the concentration and position of the hydro

英文关键词： Metal/graphene planar junction；interface effect；first-principle calculation；graphene allotropes；transport properties