The on-surface synthesis method allows the fabrication of atomically precise narrow graphene nanoribbons(GNRs),which bears great potential in electronic applications.Here,we synthesize armchair graphene nanoribbons(AG...The on-surface synthesis method allows the fabrication of atomically precise narrow graphene nanoribbons(GNRs),which bears great potential in electronic applications.Here,we synthesize armchair graphene nanoribbons(AGNRs)and chevron-type graphene nanoribbons(CGNRs)array on a vicinal Au(111112)surface using 10,10′-dibromo-9,9′-bianthracene(DBBA)and 6,12-dibromochrysene(DBCh)as precursors,respectively.This process creates spatially wellaligned GNRs,as characterized by scanning tunneling microscopy.AGNRs show strong Raman linear polarizability for application in optical modulation devices.Different from the distinct polarization of AGNRs,only weak polarization exists in CGNRs polarized Raman spectrum,which suggests that the presence of the zigzag boundary in the nanoribbon attenuates the polarization rate as an important factor affecting the polarization.We analyze the Raman activation mode of CGNRs using the peak polarization to expand the application of the polarization Raman spectroscopy in nanoarray analysis.展开更多
Topological defects in graphene induce structural and electronic modulations.Knowing exact nature of brokensymmetry states around the individual atomic defects of graphene is very important for understanding the elect...Topological defects in graphene induce structural and electronic modulations.Knowing exact nature of brokensymmetry states around the individual atomic defects of graphene is very important for understanding the electronic properties of this material.We investigate structural dependence on localized electronic states in the vicinity of topological defects on a highly oriented pyrolytic graphite(HOPG)surface,using scanning tunneling microscopy and spectroscopy.Several inherent topological defects on the HOPG surface and the local density of states surrounding them are explored,visualized as scattering wave-related(√3×√3)R30∘superstructures and honeycomb superstructures.In addition,the superstructures observed near the grain boundary have a much higher decay length at specific sites than that reported previously,indicating far greater electron scattering on the quasi-periodic grain boundary.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.61901200)the Yunnan Fundamental Research Projects(Grant Nos.2019FD041,202101AU070043,202101AV070008+2 种基金202101AW070010)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.NXDB30010000)the Dongguan Innovation Research Team Program。
文摘The on-surface synthesis method allows the fabrication of atomically precise narrow graphene nanoribbons(GNRs),which bears great potential in electronic applications.Here,we synthesize armchair graphene nanoribbons(AGNRs)and chevron-type graphene nanoribbons(CGNRs)array on a vicinal Au(111112)surface using 10,10′-dibromo-9,9′-bianthracene(DBBA)and 6,12-dibromochrysene(DBCh)as precursors,respectively.This process creates spatially wellaligned GNRs,as characterized by scanning tunneling microscopy.AGNRs show strong Raman linear polarizability for application in optical modulation devices.Different from the distinct polarization of AGNRs,only weak polarization exists in CGNRs polarized Raman spectrum,which suggests that the presence of the zigzag boundary in the nanoribbon attenuates the polarization rate as an important factor affecting the polarization.We analyze the Raman activation mode of CGNRs using the peak polarization to expand the application of the polarization Raman spectroscopy in nanoarray analysis.
基金Supported by the National Natural Science Foundation of China(Grant Nos.11674136 and 61901200)Yunnan Province for Recruiting High-Caliber Technological Talents(Grant No.1097816002)+2 种基金Reserve Talents for Yunnan Young and Middle Aged Academic and Technical Leaders(Grant No.2017HB010)the Yunnan Province Science and Technology Plan Project(Grant No.2019FD041)the China Postdoctoral Science Foundation,and the Yunnan Province Postdoctoral Science Foundation.
文摘Topological defects in graphene induce structural and electronic modulations.Knowing exact nature of brokensymmetry states around the individual atomic defects of graphene is very important for understanding the electronic properties of this material.We investigate structural dependence on localized electronic states in the vicinity of topological defects on a highly oriented pyrolytic graphite(HOPG)surface,using scanning tunneling microscopy and spectroscopy.Several inherent topological defects on the HOPG surface and the local density of states surrounding them are explored,visualized as scattering wave-related(√3×√3)R30∘superstructures and honeycomb superstructures.In addition,the superstructures observed near the grain boundary have a much higher decay length at specific sites than that reported previously,indicating far greater electron scattering on the quasi-periodic grain boundary.
