Photoluminescence side band spectroscopy of individual single-walled carbon nanotubes
Photoluminescence spectra of single-walled carbon nanotubes (SWCNTs) have been recorded and analyzed for selected individual nanotubes and structurally sorted bulk samples to clarify the nature of secondary emission features. Room temperature spectra show, in addition to the main peak arising from the E 11 bright exciton, three features at lower frequency, which are identified here (in descending order of energy difference from E 11 emission) as G 1, X 1, and Y 1. The weakest (G 1) is interpreted as a vibrational satellite of E 11 involving excitation of the ~1600 cm -1 G mode. The X 1 feature, although more intense than G 1, has a peak amplitude only ~3% of E 11. X 1 emission was found to be polarized parallel to E 11 and to be separated from that peak by 1068 cm -1 in SWCNTs with natural isotopic abundance. The separation remained unchanged for several ( n,m) species, different nanotube environments, and various levels of induced axial strain. In 13C SWCNTs, the spectral separation decreased to 1023 cm -1. The measured isotopic shift points to a phonon-assisted transition that excites the D vibration. This supports prior interpretations of the X 1 band as emission from themore »
- Authors:
-
[1];
[1];
[2];
[1]
- Rice Univ., Houston, TX (United States)
- National Renewable Energy Lab. (NREL), Golden, CO (United States)
- Publication Date:
- Report Number(s):
- NREL/JA-5900-67219
Journal ID: ISSN 1932-7447
- Grant/Contract Number:
- AC36-08GO28308
- Type:
- Accepted Manuscript
- Journal Name:
- Journal of Physical Chemistry. C
- Additional Journal Information:
- Journal Volume: 120; Journal Issue: 41; Journal ID: ISSN 1932-7447
- Publisher:
- American Chemical Society
- Research Org:
- National Renewable Energy Lab. (NREL), Golden, CO (United States)
- Sponsoring Org:
- USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; single-walled carbon nanotubes; photoluminescence; exciton; phonon; isotopic enrichment
- OSTI Identifier:
- 1330140