Transient Absorption Spectroscopy and Imaging of Individual Chirality-Assigned Single-Walled Carbon Nanotubes

Abstract

Femtosecond transient absorption microscopy was employed to study the excited-state dynamics of individual semiconducting single-walled carbon nanotubes (SWNTs) with simultaneously high spatial (∼200 nm) and temporal (∼300 fs) resolution. Isolated SWNTs were located using atomic force microscopy, and Raman spectroscopy was employed to determine the chiral index of select nanotubes. This unique experimental approach removes sample heterogeneity in ultrafast measurements of these complex materials. Transient absorption spectra of the individual SWNTs were obtained by recording transient absorption images at different probe wavelengths. These measurements provide new information about the origin of the photoinduced absorption features of SWNTs. Transient absorption traces were also collected for individual SWNTs. The dynamics show a fast, ∼1 ps, decay for all the semiconducting nanotubes studied, which is significantly faster than the previously reported decay times for SWNT suspensions. We attributed this fast relaxation to coupling between the excitons created by the pump laser pulse and the substrate.

Carbon nanotubes dispersed in aqueous solution by ruthenium(ii) polypyridyl complexes

“…Transient bleachings are due to pump laser excitation which creates E ii excitons that relax to E 11 within 100 fs. 39 This produces a depletion of the ground state that is and 1140 nm, which are consistent with bleaching of the ground state of (6,5), (7,5), (10,2), and (7,6) SWCNTs, respectively. These bleachings are red shifted in relation with HiPco nanotubes dispersed with SDBS.…”

Exciton dynamics and annihilation in WS2 2D semiconductors

“…1 and 2). 40 We have also performed PL and Raman measurements on different locations of the same flake and found no significant difference between different locations (Fig. 40 We have also performed PL and Raman measurements on different locations of the same flake and found no significant difference between different locations (Fig.…”

Highly sensitive transient absorption imaging of graphene and graphene oxide in living cells and circulating blood

“…TA imaging has been developed for visualizing single nanomaterials, such as gold nanoparticles3435, nanowires36, semiconductor and meta nanostructures3738, single-walled carbon nanotubes394041. Recently, TA spectroscopy and imaging have been employed to study the carrier dynamics in graphene4243 and graphene oxide4445 with limited sensitivity.…”