Intratube Exciton Resonance Raman Signature of Intertube Excitons in Compositionally-Defined Carbon Nanotube Bundles
Angela R. Hight Walker, Jeffrey R. Simpson
Electronic interactions in low-dimensional nanomaterial heterostructures can lead to novel optical response arising from exciton delocalization over the constituent materials. Similar phenomena have been suggested to arise between closely interacting semiconducting single wall carbon nanotubes (SWCNTs) of identical structure. While not yet probed in detail, such behavior in SWCNTs has potential to open a path to new exciton physics, impact exciton transport mechanisms in SWCNT networks, and place SWCNTs as one-dimensional models for such behaviors in systems of higher dimensionality. Here we use resonance Raman spectroscopy as a probe of intertube interactions in nanotube bundles that have been enriched in the (6, 5) chirality. Raman excitation pro les for the radial breathing mode and G-mode display a previously unobserved sharp feature that is superimposed on the typical intrinsic exciton resonance response. We show the feature is evidence for creation of intertube excitons, with the response being generated as the result of interaction between the intratube and intertube excitons whose spectral responses overlap. The sharp spectral feature is further identifed as a Fano resonance. Furthermore, the universality of the model suggests that similar Raman excitation pro le features may be observed for interlayer exciton resonances in 2D multilayered systems.
and Simpson, J.
Intratube Exciton Resonance Raman Signature of Intertube Excitons in Compositionally-Defined Carbon Nanotube Bundles, Nature Communication, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=924066
(Accessed October 25, 2021)