项目名称： 二维薄层晶体材料的显微共焦光调制反射光谱研究

项目编号： No.61474067

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 无线电电子学、电信技术

项目作者： 罗向东

作者单位： 南通大学

项目金额： 78万元

中文摘要： 独特的二维结构、优良的晶体质量和特殊的电子能带结构特性给二维薄层晶体材料带来了丰富而新奇的物理性质。二维薄层晶体材料尺寸通常小于20微米，且由于层数不同，其电子能带结构具有十分显著的差异，有的从零带隙变为微带隙，有的从直接带隙转为间接带隙。因此，使用通常的光荧光谱、光反射光谱等很难去有效研究它们的更多电子能带结构临界点跃迁。本项目通过微剥离技术获得石墨烯和二硫化钼的二维薄层晶体样品，利用光学显微镜、椭圆偏振谱仪、原子力显微镜和显微拉曼谱确定层数。通过测试其显微光荧光谱和显微拉曼光谱等来研究它们的结构和基本物理性质。然后，按照从厚到薄的顺序测试不同层数的二维薄层晶体材料的显微共焦光调制反射光谱，并结合其他实验和理论结果，分析二维薄层晶体材料的电子能带结构多个临界点的跃迁性质。本项目的开展将为二维薄层晶体材料的电子能带结构的理论研究及其器件应用提供新的思路和实验方案。

中文关键词： 显微共焦；光调制反射光谱；二维薄层晶体；石墨烯；二硫化钼

英文摘要： The two-dimensional structure, great crystal quality and unusual electronic band structure bring two-dimensional ultrathin crystals volatile and peculiar characteristics. The size of two-dimensional ultrathin crystals are normally 20 micrometer, and their electronic band structures are distinct with different layers. The graphene's bandgap can change from zero to 45 meV, and the bandgap of MoS2 is from undirect to direct. Using routine optical spectra measurements to study two-dimensional ultrathin crystals is unsuitable. In this proposal, graphene and MoS2 ultrathin crystals are made by micro-exfoliation method, and optical microscope, elliptical polarization spectrometer, atomic force microscope and micro-Raman spectrometer are applied to decide the layers of samples. And micro-photoluminescence and micro-Raman spectra are used to study their basic physics characteristics, more important， from thick to thin，the microscopic confocal photo-modulated reflectance spectra of our two-dimensional ultrathin crystals are measured. At last, with all experimental and theoretical results，the transition characteristics of singular points in electronic band structures are studied in detail.

英文关键词： microscopic confocal;photo-modulation reflectance;two-dimensional ultrathin crystal;graphene;MoS2