We,for the first time,report the nanoscopic imaging study of anomalous infrared(IR)phonon enhancement of bilayer graphene,originated from the charge imbalance between the top and bottom layers,resulting in the enhance...We,for the first time,report the nanoscopic imaging study of anomalous infrared(IR)phonon enhancement of bilayer graphene,originated from the charge imbalance between the top and bottom layers,resulting in the enhancement of E1u mode of bilayer graphene near 0.2 eV.We modified the multifrequency atomic force microscope platform to combine photo-induced force microscope with electrostatic/Kelvin probe force microscope constituting a novel hybrid nanoscale optical-electrical force imaging system.This enables to observe a correlation between the IR response,doping level,and topographic information of the graphene layers.Through the nanoscale spectroscopic image measurements,we demonstrate that the charge imbalance at the graphene interface can be controlled by chemical(doping effect via Redox mechanism)and mechanical(triboelectric effect by the doped cantilever)approaches.Moreover,we can also diagnosis the subsurface cracks on the stacked few-layer graphene at nanoscale,by monitoring the strain-induced IR phonon shift.Our approach provides new insights into the development of graphene-based electronic and photonic devices and their potential applications.展开更多
基金support of the KPFM calibration.J.J.,S.L.and E.S.L.acknowledge the supports from the National Research Foundation of Korea(NRF)grant(MSITGrant No.2022R1C1C1008766)+3 种基金the Nano Material Technology Development Program(Grant No.2016M3A7B6908929)funded by the Korea government.S.G.M.M.S.J.acknowledge the Basic Science Research Program through the NRF funded by the Ministry of Education(Grant No.2021R1I1A1A01057510)the support of the NRF grant funded by MSIT(2022R1A2C2092095).D.K.J.S.acknowledged to the National Research Council of Science&Technology(NST)grant by the Korea government(MSIT)(No.CRC-20-01-NFRI)and the KIST Institutional program(2E32634).
文摘We,for the first time,report the nanoscopic imaging study of anomalous infrared(IR)phonon enhancement of bilayer graphene,originated from the charge imbalance between the top and bottom layers,resulting in the enhancement of E1u mode of bilayer graphene near 0.2 eV.We modified the multifrequency atomic force microscope platform to combine photo-induced force microscope with electrostatic/Kelvin probe force microscope constituting a novel hybrid nanoscale optical-electrical force imaging system.This enables to observe a correlation between the IR response,doping level,and topographic information of the graphene layers.Through the nanoscale spectroscopic image measurements,we demonstrate that the charge imbalance at the graphene interface can be controlled by chemical(doping effect via Redox mechanism)and mechanical(triboelectric effect by the doped cantilever)approaches.Moreover,we can also diagnosis the subsurface cracks on the stacked few-layer graphene at nanoscale,by monitoring the strain-induced IR phonon shift.Our approach provides new insights into the development of graphene-based electronic and photonic devices and their potential applications.
