Brightening of Long, Polymer-Wrapped Carbon Nanotubes by sp³ Functionalization in Organic Solvents

Abstract

The functionalization of semiconducting single-walled carbon nanotubes (SWNTs) with sp 3 defects that act as luminescent exciton traps is a powerful means to enhance their photoluminescence quantum yield (PLQY) and to add optical properties. However, the synthetic methods employed to introduce these defects are currently limited to aqueous dispersions of surfactant-coated SWNTs, often with short tube lengths, residual metallic nanotubes, and poor film-formation properties. In contrast to that, dispersions of polymer-wrapped SWNTs in organic solvents feature unrivaled purity, higher PLQY, and are easily processed into thin films for device applications. Here, we introduce a simple and scalable phase-transfer method to solubilize diazonium salts in organic nonhalogenated solvents for the controlled reaction with polymer-wrapped SWNTs to create luminescent aryl defects. Absolute PLQY measurements are applied to reliably quantify the defect-induced brightening. The optimization of defect density and trap depth results in PLQYs of up to 4% with 90% of photons emitted through the defect channel. We further reveal the strong impact of initial SWNT quality and length on the relative brightening by sp 3 defects. The efficient and simple production of large quantities of defect-tailored polymer-sorted SWNTs enables aerosol-jet printing and spin-coating of thin films with bright and nearly reabsorption-free defect emission, which are desired for carbon nanotube-based near-infrared light-emitting devices.

Separation of Semiconducting Carbon Nanotubes Using Conjugated Polymer Wrapping

“…Adding pyridine groups to the backbone seems to be able to disperse larger diameter SWNTs, such as those produced by laser vaporization or arc discharge [ 36 , 51 ]. The extracted s-SWNTs have both high purity and high yield, with a reduced diameter abundance, which is more desired for electrical and optical uses [ 52 , 53 , 54 , 55 , 56 ]. Tange et al found that PFO-Py (P4) could selectively extract (13, 5) SWNT [ 52 ].…”

Population of Exciton–Polaritons via Luminescent sp3 Defects in Single-Walled Carbon Nanotubes

“…The deep optical traps (100–200 meV) lead to a strong red shift of the emission and facilitate high-purity single-photon emission at room temperature. 47 , 48 These defects can be created synthetically by arylation, 43 , 44 alkylation, 49 or covalent oxygen doping. 47 Depending on the binding configuration, two main types of defects have been identified, commonly named E 11 * (1.05 eV or 1180 nm) and E 11 * – (0.95 eV or 1300 nm) for (6,5) nanotubes (see Figure 1 , right).…”

Quantendefekte als Werkzeugkasten für die kovalente Funktionalisierung von Kohlenstoffnanoröhren mit Peptiden und Proteinen

“…[30] Diese Technik ermçglichte auch die Abstimmung der Defektfluoreszenz sowohl in Bezug auf die Intensitäta ls auch auf die Emissionswellenlänge über verschiedene Substituenten am Aryl/Alkyl-Defekt. [31][32][33][34] In den letzten Jahren wurde über eine Reihe verschiedener Sauerstoff-und Aryl-Defekte berichtet, die nun sehr vielversprechende Werkzeuge fürd ie Erzeugung von helleren/modifizierten SWCNTs, [31,35,36] pH- [37] or Saccharid [38] -Sensoren, kurzen fluoreszierenden SWCNTs fürd ie hochauflçsende Mikroskopie [39] oder Einzelphotonenquellen für das Quanten-Computing sind. [40,41] Darüber hinaus verschiebt dieses neue Defekt-induzierte Fluoreszenzsignal die Emission noch weiter in das Biotransparenzfenster,w as zu noch besseren Gewebepenetrationseigenschaften führt.…”