Tip-enhanced Near-Field Optical Spectroscopy on Single-Walled Carbon Nanotubes

摘要: High resolution optical methods overcome the diraction limit, a step essential for understanding the physical and chemical properties of nanostructures. In this work, I applied tip-enhanced near-eld microscopy (TENOM) to study single-wall carbon nanotubes (SWNTs) with nanoscale spatial resolution. Simultaneously obtained near-eld Raman scattering photoluminescence (PL) data is shown provide information unprecedented detail on nanotube structure resulting phonon exciton properties. Near-eld PL is found be more localized along single nanotubes than Raman scattering in most cases due to defects environmental perturbations. By detecting PL spectra, my work has shown energy variations same induced by environment. The local response DNA-wrapping reveals large DNA-induced redshifts exciton energy that are two times higher indicated spatially averaging confocal microscopy. Exciton energy transfer between semiconducting observed rst time limited to small distances because competing fast non-radiative relaxation. The mechanism is explained F�orster-type electromagnetic coupling. addition, towards end of nanotube, decay length scale 15-40 nm which attributed exciton propagation followed additional relaxation at end. dierent enhancement mechanisms lead dierent enhancement factors of the signals. can stronger very low initial quantum yield nanotubes. signal scattering and also exhibit tip-sample distance dependencies PL quenching eects from gold tip. results achieved thesis highlight enormous capabilities TENOM investigation surfaces.