Ultrafast Exciton Trapping at sp³ Quantum Defects in Carbon Nanotubes

Journal Article · Tue Oct 29 00:00:00 EDT 2019 · ACS Nano

DOI:https://doi.org/10.1021/acsnano.9b06279· OSTI ID:1607370

Sykes, Matthew E. ^[1]; Kim, Mijin ^[2]; Wu, Xiaojian ^[2]; Wiederrecht, Gary P. ^[1]; Peng, Lintao ^[1]; Wang, YuHuang ^[2]; Gosztola, David J. ^[1]; Ma, Xuedan ^[1]

---

1. Argonne National Lab. (ANL), Lemont, IL (United States). Center for Nanoscale Materials
2. Univ. of Maryland, College Park, MD (United States)

Semiconducting single-walled carbon nanotubes (SWCNTs) constitute an ideal platform for developing near-infrared biosensors, single photon sources, and nanolasers due to their distinct optical and electrical properties. Covalent doping of SWCNTs has recently been discovered as an efficient approach in enhancing their emission intensities. We perform pump–probe studies of SWCNTs that are covalently doped with sp³ quantum defects and reveal strikingly different exciton formation dynamics and decay mechanisms in the presence of the defect sites. We show that, in highly doped SWCNTs, ultrafast trapping of excitons at the defect sites can outpace other photodynamic processes and lead to ground-state photobleaching of the quantum defects. Our fitting of the transient data with a kinetic model also reveals an upper limit in the quantum defect density for obtaining highly luminescent SWCNTs without causing irreversible damage. In conclusion, these findings not only deepen our understanding of the photodynamics in covalently doped SWCNTs but also reveal critical information for the design of bright near-infrared emitters that can be utilized in biological, quantum information, and nanophotonic applications.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL (United States)
• Sponsoring Organization: National Science Foundation (NSF); USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
• Grant/Contract Number: AC02-06CH11357
• OSTI ID: 1607370
• Journal Information: ACS Nano, Journal Name: ACS Nano Journal Issue: 11 Vol. 13; ISSN 1936-0851
• Publisher: American Chemical Society (ACS)
• Country of Publication: United States
• Language: English

Related Subjects

77 NANOSCIENCE AND NANOTECHNOLOGY
exciton trapping
ground-state photobleaching
pump-probe spectroscopy
quantum defects
single-walled carbon nanotubes
stimulated emission