摩擦力显微镜表征二维材料晶格结构研究  

Crystal lattice imaging of two-dimensional materials by friction force microscopy

作　　者：郑荣戌 王经纬 张云豪 农慧雨 吴沁柯 武科佑 谭隽阳 黄子阳 余强敏 刘碧录 Rongxu Zheng;Jingwei Wang;Yunhao Zhang;Huiyu Nong;Qinke Wu;Keyou Wu;Junyang Tan;Ziyang Huang;Qiangmin Yu;Bilu Liu(Shenzhen Geim Graphene Center,Institute of Materials Research,Tsinghua-Berkeley Shenzhen Institute,Tsinghua Shenzhen International Graduate School,Tsinghua University,Shenzhen 518055,China)

机构地区：[1]清华大学,清华大学深圳国际研究生院,清华-伯克利深圳学院,材料研究院,深圳盖姆石墨烯中心,深圳518055

出　　处：《科学通报》2023年第22期2924-2933,共10页Chinese Science Bulletin

基　　金：国家重点研发计划(2018YFA0307300);国家杰出青年科学基金(52125309);国家自然科学基金(51991343,51991340,51920105002,52102179);广东省珠江人才团队项目(2017ZT07C341);广东省自然科学基金(2023A1515011752);深圳市科技创新委员会自然科学基金(JCYJ20200109144620815,JCYJ20200109144616617,JCYJ20220818101014029);清华大学“水木学者”计划(2022SM092);中国博士后科学基金(021M691715)资助。

摘　　要：摩擦力显微镜(friction force microscopy,FFM)是一种基于摩擦力信号的原子力显微镜,能够对二维材料晶格进行快速、无损的高分辨成像.然而,由于热漂移、黏附力、表面静电等因素的影响,环境条件下二维材料的高分辨FFM成像仍面临着巨大挑战.基于以上问题,本文以高定向热解石墨为标准样品,通过对探针在样品表面黏滑行为的分析,系统研究了探针弹性常数、正应力和扫描速度对高分辨FFM成像的影响,并建立了一套可靠的二维材料晶格结构表征方法.该方法能够获得精确的结构信息,所测得的二维材料晶格常数平均误差小于2.3%.此外,该方法还适用于化学气相沉积法和剥离法制备的多种二维材料,展现出较高的普适性.本文的研究结果为环境条件下二维材料晶格结构的精确表征提供了新思路.Two-dimensional(2D)materials have attracted wide attention in condensed matter physics,nanomaterials science,and other fields due to their atomically flat surface,unique band structure,and excellent electrical and optical properties.Due to the atomic thickness,the surface structure of 2D materials is closely related to their catalytic,electric,and optoelectric properties.Accurate characterization of 2D lattice is of great importance for clarifying the relationship between the properties and structures of 2D materials.As a non-destructive mode based on atomic force microscopy(AFM),friction force microscopy(FFM)can visualize the lattice structure of 2D materials under atmospheric conditions.Although there have already been a series of reports on FFM imaging of 2D material lattice,such experiments are still challenging.For example,the FFM lattice images of 2D materials suffer from obvious distortion and low signal-to-noise ratio.The reported attempts by FFM are mainly limited to 2D materials such as graphene and MoS_(2).Whether this technique applies to other 2D materials(such as 2D mineral materials)is not clear.In addition,the relationship between the measurement parameters of FFM and imaging quality has not been deeply explored,which limits the wide application of FFM.Therefore,clarifying the internal relationship between the experimental parameters and the lattice imaging,and developing a robust and reliable lattice characterization method are urgent issues in the field.Here,taking the freshly exfoliated highly oriented pyrolytic graphite as an example,we systematically investigate the key factors affecting the high-resolution imaging of FFM such as spring constant,normal force,and scan speed of tips.It is found that the signal-to-noise ratio of the high-resolution image is related to the spring constant of the selected probe.The proper normal force makes the probe maintain a single-point slip,and its stick-slip period is consistent with the lattice period,reflecting the accurate information of the lattice.In ad

关 键 词：二维材料 摩擦力显微镜 高分辨结构表征 晶格常数 石墨烯 二维矿物材料 

分 类 号：TB34[一般工业技术—材料科学与工程]