摘要
Nanocontact properties of two-dimensional(2D)materials are closely dependent on their unique nanomechanical systems,such as the number of atomic layers and the supporting substrate.Here,we report a direct observation of toplayer-dependent crystallographic orientation imaging of 2D materials with the transverse shear microscopy(TSM).Three typical nanomechanical systems,MoS_(2) on the amorphous SiO_(2)/Si,graphene on the amorphous SiO_(2)/Si,and MoS_(2) on the crystallized Al_(2)O_(3),have been investigated in detail.This experimental observation reveals that puckering behaviour mainly occurs on the top layer of 2D materials,which is attributed to its direct contact adhesion with the AFM tip.Furthermore,the result of crystallographic orientation imaging of MoS_(2)/SiO_(2)/Si and MoS_(2)/Al_(2)O_(3) indicated that the underlying crystalline substrates almost do not contribute to the puckering effect of 2D materials.Our work directly revealed the top layer dependent puckering properties of 2D material,and demonstrate the general applications of TSM in the bilayer 2D systems.
基金
This work was supported by the National Natural Science Foundation of China(NSFC,Grant Nos.21622304,61674045,and 11604063)
Ministry of Science and Technology(MOST)of China(Grant No.2016YFA0200700)
Strategic Priority Research Program,Key Research Program of Frontier Sciences and Instrument Developing Project of Chinese Academy of Sciences(CAS
Grant Nos.XDB30000000,QYZDB-SSW-SYS031,and YZ201418)
Grant-in-Aid for Scientific Research from Japan Society for the Promotion of Science(JSPS)from the Ministry of Education,Culture,Sports,Science,and Technology of Japan(Grant Nos.JP16H06327,JP16H06504,JP17H01061,and JP17H010610)
Osaka University’s International Joint Research Promotion Program(Grant Nos.J171013014,J171013007,J181013006,and Ja19990011)
Z.H.Cheng was supported by Distinguished Technical Talents Project and Youth Innovation Promotion Association CAS,the Fundamental Research Funds for the Central Universities,and the Research Funds of Renmin University of China(Grant No.18XNLG01)
S.Chen appreciate the support from Beijing Natural Science Foundation(Grant No.2192024).
