摘要
The interlayer bonding in two-dimensional(2D)materials is particularly important because it is not only related to their physical and chemical stability but also afects their mechanical,thermal,elec-tronic,optical,and other properties.To address this issue,we report the direct characterization of the interlayer bonding in 2D SnSe using contact-resonance atomic force microscopy(CR-AFM)in.this study.Site-specific CR spectroscopy and CR force spectroscopy measurements are performed on both SnSe and its supporting SiO2/Si substrate comparatively.Based on the cantilever and contact mechanic models,the contact stifness and vertical Young's modulus are evaluated in comparison with SiO2/Si as a reference material.The interlayer bonding of SnSe is further analyzed in combination with the semi-analytical model and density functional theory calculations.The direct characteriza-tion of interlayer interactions using this non-destructive methodology of CR-AFM would facilitate a better understanding of the physical and chemical properties of 2D layered materials,specifically for interlayer intercalation and vertical heterostructures.
基金
This project was supported by the Min-istry of Science and Technology(MOST)of China(Grant Nos.2016YFA0200700 and 2018YFE0202700)
the National Natural Science Foundation of China(NSFC)(Grant Nos.21622304,61674045,11604063,11622437,11974422,61911540074,11804247,and 61674171)
Strategic Priority Research Program,Key Research Program of Frontier Sciences,and Instrument Developing Project of Chinese Academy of Sciences(CAS)(Grant Nos.XDB000000,QYZDB-SSW-8Y5031,and YZ201418)
Z.H.Cheng was supportod by Distinguished Technical Talents Project and Youth Innovation Promotion Association CAS,Fundamental Research Funds for the Central Universities,and Research Funds of Renmin University of China(Grant Nos.18XNLG01 and 19XNQ025)
Calculations were performed at the Physics Lab of High-Performance Computing of Renmin University of China and Shanghal Supercomputer Center.
