Structure-Dependent Fluorescence Efficiencies of Individual Single-Walled Carbon Nanotubes

Strong Acoustic Phonon Localization in Copolymer-Wrapped Carbon Nanotubes

“…43 The observed isotope shift for individual SWCNTs is 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 9 also in excellent agreement with previous findings carried out with large ensembles of SWCNTs from the same LV growth chamber 44,45 as well as CVD grown SWCNTs. 46 For these isotope engineered SWCNTs, the signature of exciton emission was confirmed in each case by the laser detuning technique described in Figure 2 with yields of about 10%-30% for finding (6,4) chirality SWCNTs, with the exception of the 100% 13 C samples where we found no PL signal around 890 nm that would correspond to (6,4) for 20% 13 C admixing. This is an indication that the ZPL width of these SWCNTs is pinned to extrinsic effects.…”

“…The first goal of our study was to isolate individual SWCNTs with known chirality, targeting in particular semiconducting carbon nanotubes with (6,4) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Figure 1a shows a schematic of the sample design consisting of a bottom gold mirror, PS spacer, dispersed SWCNT layer, and top PS capping layer. To predominantly excite (6,4) chirality SWCNTs that are known to emit at 890 nm (1.39 eV), we utilized phonon-assisted excitation around 780 nm (1.59 eV), which results in quasi-resonant pumping of excitons into their excited states via onephonon absorption processes involving the zone-center optical phonons 31 (G-mode phonon with energy of about 200 meV), as illustrated in Figure 1b.…”

“…These data provide an upper bound for the contribution of 13 To probe for the possibility of impurity-bound exciton emission from excitons localized at unintentional dopant sites or defects, we investigated the E 11 emission spectra of 48 SWCNTs. Figure 4 displays the low pump power spectra of 10 individual SWCNTs for three different chiralities including (6,4), (6,5), and (5,4) SWCNTs. We note that the pump power for the quasi-resonant phonon side band excitation was deliberately kept low enough (≤ 1mW/µm 2 ) to avoid optically induced damage that is known, in particular for E 22 excitation, to induce blinking 30,50 and additional defect related exciton emission lines.…”

Semiconducting carbon nanotube/fullerene blended heterojunctions for photovoltaic near-infrared photon harvesting

“…In brief, we used the selectivity of poly(9,9-dioctylfluorene-2,7-diyl) (PFO) to isolate small diameter, near-armchair s-SWCNTs in toluene from heterogeneously produced carbon nanotube powders. s-SWCNT and PFO concentrations in solution were calculated from absorption measurements using the optical cross section estimates of Tsyboulski et al [19] and Islam et al [20] for s-SWNT E 22 absorption at λ = 600-800 nm, and reference solutions of PFO at λ = 400 nm [14]. For device fabrication, PCBM was added to give a chlorobenzene solution of x:5:4 PCBM:PFO:s-SWCNTs by weight, where x was varied from 5 to 20.…”

Enhanced solubilization of large-diameter single-walled carbon nanotubes with amino-functionalized dipyrene nanotweezers

“…We calculated the relative abundance of each SWNT species based on its PL intensity, the results were summarized in Table 1. No correction has been made for possible differences in the quantum efficiencies of different (n, m)-SWNTs, therefore the abundance shown in Table 1 is not the exact ratio in their amount, but to be estimated one [43]. After the extraction of 76-CoMoCAT, the PL map shown in Fig.…”