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Palotás J, Negyedi M, Kollarics S, Bojtor A, Rohringer P, Pichler T, Simon F. Incidence of Quantum Confinement on Dark Triplet Excitons in Carbon Nanotubes. ACS Nano 2020; 14:11254-11261. [PMID: 32790277 PMCID: PMC7513465 DOI: 10.1021/acsnano.0c03139] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Accepted: 08/13/2020] [Indexed: 05/28/2023]
Abstract
The photophysics of single-wall carbon nanotubes (SWCNTs) is intensively studied due to their potential application in light harvesting and optoelectronics. Excited states of SWCNTs form strongly bound electron-hole pairs, excitons, of which only singlet excitons participate in application relevant optical transitions. Long-living spin-triplet states hinder applications, but they emerge as candidates for quantum information storage. Therefore, knowledge of the triplet exciton energy structure, in particular in a SWCNT chirality dependent manner, is greatly desired. We report the observation of light emission from triplet state recombination, i.e., phosphorescence, for several SWCNT chiralities using a purpose-built spectrometer. This yields the singlet-triplet gap as a function of the SWCNT diameter, and it follows predictions based on quantum confinement effects. Saturation under high microwave power (up to 10 W) irradiation allows the spin-relaxation time for triplet states to be determined. Our study sensitively discriminates whether the lowest optically active state is populated from an excited state on the same nanotube or through Förster exciton energy transfer from a neighboring nanotube.
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Affiliation(s)
- J. Palotás
- Department
of Physics and MTA-BME Lendület Spintronics Research Group
(PROSPIN), Budapest University of Technology
and Economics, PO Box 91, H-1521 Budapest, Hungary
- Institute
for Molecules and Materials, FELIX Laboratory, Radboud University, Toernooiveld 7, 6525ED Nijmegen, The Netherlands
| | - M. Negyedi
- Department
of Physics and MTA-BME Lendület Spintronics Research Group
(PROSPIN), Budapest University of Technology
and Economics, PO Box 91, H-1521 Budapest, Hungary
- Universität
Tübingen Physikalische Institut, Auf der Morgenstelle 14D, 72076 Tübingen, Germany
- HighFinesse
GmbH, Auf der Morgenstelle
14D, 72076 Tübingen, Germany
| | - S. Kollarics
- Department
of Physics and MTA-BME Lendület Spintronics Research Group
(PROSPIN), Budapest University of Technology
and Economics, PO Box 91, H-1521 Budapest, Hungary
| | - A. Bojtor
- Department
of Physics and MTA-BME Lendület Spintronics Research Group
(PROSPIN), Budapest University of Technology
and Economics, PO Box 91, H-1521 Budapest, Hungary
| | - P. Rohringer
- Faculty
of Physics, University of Vienna, Strudlhofgasse 4, Vienna A-1090, Austria
| | - T. Pichler
- Faculty
of Physics, University of Vienna, Strudlhofgasse 4, Vienna A-1090, Austria
| | - F. Simon
- Department
of Physics and MTA-BME Lendület Spintronics Research Group
(PROSPIN), Budapest University of Technology
and Economics, PO Box 91, H-1521 Budapest, Hungary
- Laboratory
of Physics of Complex Matter, École
Polytechnique Fédérale de Lausanne, Lausanne CH-1015, Switzerland
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Negyedi M, Palotás J, Gyüre B, Dzsaber S, Kollarics S, Rohringer P, Pichler T, Simon F. An optically detected magnetic resonance spectrometer with tunable laser excitation and wavelength resolved infrared detection. Rev Sci Instrum 2017; 88:013902. [PMID: 28147648 DOI: 10.1063/1.4973446] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We present the development and performance of an optically detected magnetic resonance (ODMR) spectrometer. The spectrometer represents advances over similar instruments in three areas: (i) the exciting light is a tunable laser source which covers much of the visible light range, (ii) the optical signal is analyzed with a spectrograph, (iii) the emitted light is detected in the near-infrared domain. The need to perform ODMR experiments on single-walled carbon nanotubes motivated the present development and we demonstrate the utility of the spectrometer on this material. The performance of the spectrometer is critically compared to similar instruments. The present development opens the way to perform ODMR studies on various new materials such as molecules and luminescent quantum dots where the emission is in the near-infrared range and requires a well-defined excitation wavelength and analysis of the scattered light.
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Affiliation(s)
- M Negyedi
- Department of Physics, Budapest University of Technology and Economics and MTA-BME Lendület Spintronics Research Group (PROSPIN), P.O. Box 91, H-1521 Budapest, Hungary
| | - J Palotás
- Department of Physics, Budapest University of Technology and Economics and MTA-BME Lendület Spintronics Research Group (PROSPIN), P.O. Box 91, H-1521 Budapest, Hungary
| | - B Gyüre
- Department of Physics, Budapest University of Technology and Economics and MTA-BME Lendület Spintronics Research Group (PROSPIN), P.O. Box 91, H-1521 Budapest, Hungary
| | - S Dzsaber
- Department of Physics, Budapest University of Technology and Economics and MTA-BME Lendület Spintronics Research Group (PROSPIN), P.O. Box 91, H-1521 Budapest, Hungary
| | - S Kollarics
- Department of Physics, Budapest University of Technology and Economics and MTA-BME Lendület Spintronics Research Group (PROSPIN), P.O. Box 91, H-1521 Budapest, Hungary
| | - P Rohringer
- Faculty of Physics, University of Vienna, Strudlhofgasse 4., Vienna A-1090, Austria
| | - T Pichler
- Faculty of Physics, University of Vienna, Strudlhofgasse 4., Vienna A-1090, Austria
| | - F Simon
- Department of Physics, Budapest University of Technology and Economics and MTA-BME Lendület Spintronics Research Group (PROSPIN), P.O. Box 91, H-1521 Budapest, Hungary
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