二维原子晶体的低电压扫描透射电子显微学研究

发布时间：2018-05-25 16:45

本文选题：二维原子晶体 + 扫描透射电子显微学　；参考：《物理学报》2017年21期

【摘要】：二维原子晶体材料,如石墨烯和过渡金属硫族化合物等,具有不同于其块体的独特性能,有望在二维半导体器件中得到广泛应用.晶体中的结构缺陷对材料的物理化学性能有直接的影响,因此研究结构缺陷和局域物性之间的关联是当前二维原子晶体研究中的重要内容,需要高空间分辨率的结构研究手段.由于绝大部分二维原子晶体在高能量高剂量的电子束辐照下容易发生结构损伤,利用电子显微方法对二维原子晶体缺陷的研究面临诸多挑战.低电压球差校正扫描透射电子显微(STEM)技术的发展,一个主要目标就是希望在不损伤结构的前提下对二维原子晶体的本征结构缺陷进行研究.在STEM下,多种不同的信号能够被同步采集,包括原子序数衬度高分辨像和电子能量损失谱等,是表征二维原子晶体缺陷的有力工具,不但能对材料的本征结构进行单原子尺度的成像和能谱分析,还能记录材料结构的动态变化.通过调节电子束加速电压和电子辐照剂量,扫描透射电子显微镜也可以作为电子刻蚀二维原子晶体材料的平台,用于加工新型纳米结构以及探索新型二维原子晶体的原位制备.本综述主要以本课题组在石墨烯和二维过渡金属硫族化合物体系的研究为例,介绍低电压扫描透射电子显微学在二维原子晶体材料研究中的实际应用.
[Abstract]:Two-dimensional atomic crystal materials, such as graphene and transition metal sulfur compounds, are expected to be widely used in two-dimensional semiconductor devices due to their unique properties different from their bulk. The structural defects in crystals have a direct impact on the physical and chemical properties of the materials. Therefore, the study of the correlation between the structural defects and the local physical properties is an important part of the current two-dimensional atomic crystal research, which requires a high spatial resolution of the structural research methods. Because most two-dimensional atomic crystals are vulnerable to structural damage under high energy and high dose electron beam irradiation, the study of two-dimensional atomic crystal defects by electron microscopy is faced with many challenges. With the development of low-voltage spherical aberration correction scanning transmission electron microscopy (STEMEM), one of the main goals is to study the intrinsic structural defects of two-dimensional atomic crystals without damaging the structure. Under STEM, many different signals can be collected synchronously, including atomic number contrast high resolution image and electron energy loss spectrum, which is a powerful tool to characterize the defects of two-dimensional atomic crystal. Not only can the intrinsic structure of the material be imaged on a single atomic scale and the energy spectrum can be analyzed, but also the dynamic changes of the material structure can be recorded. By adjusting the electron beam acceleration voltage and the dose of electron irradiation, the scanning transmission electron microscope can also be used as a platform for electron etching of two-dimensional atomic crystal materials, for processing new nanostructures and for exploring the in-situ fabrication of new two-dimensional atomic crystals. In this review, the practical application of low voltage scanning transmission electron microscopy in the study of two-dimensional atomic crystal materials is introduced, taking the study of graphene and 2-D transition metal sulfur compounds as examples.
【作者单位】：中国科学院大学物理科学学院;中国科学院大学中国科学院真空物理重点实验室;
【基金】：国家自然科学基金(批准号:51622211) 中国科学院率先行动“百人计划”资助的课题~~
【分类号】：O73;TN16

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