Observation of rapid Auger recombination in optically excited semiconducting carbon nanotubes

Wang, Feng; Duković, Gordana; Knoesel, Ernst; Brus, L. E.; Heinz, Tony F.

doi:10.1103/physrevb.70.241403

Cited by 210 publications

(249 citation statements)

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“…The TA spectrum also involves optical transitions from a photoexcited state to excited exciton, X*, and biexciton, XX, states shown in Figure 4c and yielding −α LX (ℏω). In particular, the dip at 1.95 eV is due to X 1 → XX 6,7 and X 2 → XX 4,5 transitions that involve addition of a bright X 3,4 exciton to the photoexcited LX. This supports the interpretation of the experimental feature at this energy being due to a biexciton bound by 0.14 eV.…”

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confidence: 99%

Comprehensive Synthesis of Monohydroxy–Cucurbit[n]urils (n = 5, 6, 7, 8): High Purity and High Conversions

et al. 2015

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NRC Publications Record / Notice d'Archives des publications de CNRC:http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/ctrl?action=rtdoc&an=21277027&lang=en http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/ctrl?action=rtdoc&an=21277027&lang=fr READ THESE TERMS AND CONDITIONS CAREFULLY BEFORE USING THIS WEBSITE.http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/jsp/nparc_cp.jsp?lang=en Vous avez des questions? Nous pouvons vous aider. Pour communiquer directement avec un auteur, consultez la première page de la revue dans laquelle son article a été publié afin de trouver ses coordonnées. Si vous n'arrivez pas à les repérer, communiquez avec nous à PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca.

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confidence: 99%

Comprehensive Synthesis of Monohydroxy–Cucurbit[n]urils (n = 5, 6, 7, 8): High Purity and High Conversions

et al. 2015

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“…For high excitation densities exceeding 10 14 photons/ ͑cm 2 pulse͒, exciton-exciton annihilation or Auger-recombination was observed to dominate the excited state dynamics. 18 In the range of the low pump fluences used in this study ͑P =2−50ϫ 10 12 photons/ ͑cm 2 pulse͒͒ the measured transients resulted in constant lifetimes to within Ϯ2 ps ͓Fig. 3͑a͔͒ ruling out that the lifetime variations reported here result from multiexciton effects.…”

Section: -mentioning

confidence: 86%

Exciton decay dynamics in individual carbon nanotubes at room temperature

Gokus

Hartschuh

Harutyunyan

et al. 2008

Applied Physics Letters

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We studied the exciton decay dynamics of individual semiconducting single-walled carbon nanotubes at room temperature using time-resolved photoluminescence spectroscopy. The photoluminescence decay from nanotubes of the same ͑n , m͒ type follows a single exponential decay function, however, with lifetimes varying between about 1 and 40 ps from nanotube to nanotube. A correlation between broad photoluminescence spectra and short lifetimes was found and explained by defects promoting both nonradiative decay and vibronic dephasing. © 2008 American Institute of Physics. ͓DOI: 10.1063/1.2913009͔Based on their exceptional optical properties, singlewalled carbon nanotubes ͑SWNT͒ will eventually play an important role as nanometer-scale building blocks for optoelectronics, nanoelectronics, and biosensing. 1-3 Experimental and theoretical studies confirmed the identification of the photoluminescent state as being excitonic in nature with extremely large exciton binding energies. 4,5 The excited state energies and dynamics of SWNT attracted particular scientific interest motivated by their unique one-dimensional structure combining intriguing optical and transport properties. To date, a large number of ensemble studies using pump-probe and time-resolved photoluminescence ͑PL͒ spectroscopy exist, reporting on mono-or multiexponential relaxation dynamics with decay times ranging from few to several tens of picoseconds for different sample materials. 4,6,7 Temperature dependent PL measurements suggest that the excited state relaxation reflects a complex interplay between excitonic states of different parity that are optically bright or dark depending on their accessibility from the ground state. 8,9 At present, excited state lifetimes are thought to be limited by fast transitions to these dark states but also by quenching related to defect related trap states. Transitions between excitonic states of different parity are expected to require symmetry breaking defects or environmental perturbations. 10 Defects and environmental coupling are spatially localized by nature and a unique property of a given nanotube. As a result, ensemble measurements will always represent an averaging. Previous single nanotube PL measurements revealed a distribution of lifetimes for a single nanotube chirality ͑6,4͒ ranging from sub 20 to 180 ps with an average value of 57 ps at 87 K. 11 These studies were limited to low temperatures because of the time resolution of the utilized system. In this paper, we report on the first time-resolved PL measurements of individual ͑6,4͒ and ͑6,5͒ SWNT at room temperature. PL transients extending over more than four orders of magnitude were found to be monoexponential with lifetimes ranging from about 1 to 40 ps.Single nanotube measurements were performed using an inverted confocal microscope in combination with electronics for time-correlated single-photon counting. Laser excitation is provided by a femtosecond Ti:sapphire laser operating at 760 nm and a repetition rate of 76 MHz. A high numerical aperture obje...

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“…Using this model, WWHH calculated a lifetime of 1.7 ps for two excitons in a 1 m carbon nanotube, 11 in reasonable agreement with the experimentally determined decay rate of 3 ps. 14 This suggests that the model captures the essential features of exciton recombination in carbon nanotubes despite the simplifying approximations.…”

Section: Recombination Ratementioning

confidence: 99%

“…Experiments reveal power-law decay at short times ͑t Շ 2 ps͒, followed by exponential decay at longer times ͑t տ 5 ps͒. 2,6,7,[13][14][15][16] This suggests that there are efficient multiexciton decay processes that dominate the dynamics at high exciton densities. At lower densities, single-exciton decay is the only available relaxation pathway.…”

Section: Exciton Population Dynamicsmentioning

confidence: 99%

Nonradiative recombination of excitons in carbon nanotubes mediated by free charge carriers

Kinder

Mele

2008

Phys. Rev. B

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Free electrons or holes can mediate the nonradiative recombination of excitons in carbon nanotubes. Kinematic constraints arising from the quasi one-dimensional nature of excitons and charge carriers lead to a thermal activation barrier for the process. However, a model calculation suggests that the rate for recombination mediated by a free electron is the same order of magnitude as that of two-exciton recombination. Small amounts of doping may contribute to the short exciton lifetimes and low quantum yields observed in carbon nanotubes.

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Observation of rapid Auger recombination in optically excited semiconducting carbon nanotubes

Cited by 210 publications

References 21 publications

Comprehensive Synthesis of Monohydroxy–Cucurbit[n]urils (n = 5, 6, 7, 8): High Purity and High Conversions

Comprehensive Synthesis of Monohydroxy–Cucurbit[n]urils (n = 5, 6, 7, 8): High Purity and High Conversions

Exciton decay dynamics in individual carbon nanotubes at room temperature

Nonradiative recombination of excitons in carbon nanotubes mediated by free charge carriers

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