Mapping emissive channels of quantum dots: Influence of size and environment on energy transfer in the time domain

Faulques, Eric; Massuyeau, Florian; Wang, Q.; Seo, Dong Kyun; Jobic, Stéphane

doi:10.1063/1.3497269

Cited by 3 publications

(2 citation statements)

References 29 publications

(15 reference statements)

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“…The differences between measured and predicted ratios for band-edge emission indicate that an additional quenching mechanism, beyond the individual contributions from MPA and ZrO 2 , was active. The additional quenching may have been caused by the formation of QD–MPA–ZrO 2 assemblies and the resulting changes of polarity in the vicinity of QDs (as discussed above for quenching by ZrO 2 alone) or enhanced nonradiative energy transfer or exciton–exciton annihilation between QDs within agglomerates. − We assume that this assembly-induced quenching mechanism was also active in CdSe–MPA–TiO 2 assemblies.…”

Section: Resultsmentioning

confidence: 96%

Probing the Energetic Distribution of Injected Electrons at Quantum Dot–Linker–TiO₂ Interfaces

Sellers

Watson

2012

J. Phys. Chem. C

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We have used steady-state and time-resolved emission measurements to characterize interfacial electron transfer, or electron injection, from CdSe quantum dots (QDs) to molecularly linked TiO 2 nanoparticles. Electrons were injected from both band-edge and trap states on relatively fast (<10 −8 s) and slow (>10 −8 s) time scales. The quantum yield of electron injection from trap states decreased as the trap-state distribution was shifted, by varying excitation energy, to lower energies. This effect probably arose from a driving-force dependence of the rate constant for electron injection. In contrast, the quantum yield of electron injection from band-edge states was independent of excitation energy. Our results highlight the key role of trapped carriers in interfacial charge-transfer processes of QDs and the influence of the energies and densities of trap states on the efficiencies of such processes.

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Section: Resultsmentioning

confidence: 96%

Probing the Energetic Distribution of Injected Electrons at Quantum Dot–Linker–TiO₂ Interfaces

Sellers

Watson

2012

J. Phys. Chem. C

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“…12,14,15 To see the influence of size, defects, and low temperatures on the excitonic dynamics, we have performed time resolved PL experiments using a femtosecond laser and a streak camera system as in our previous studies. 16,17 Fig. 1(b) shows the room-temperature transient PL spectra, integrated over a time of 1 ns, for the different sizes.…”

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confidence: 99%

Temperature and size dependence of time-resolved exciton recombination in ZnO quantum dots

Musa

Massuyeau

Cario

et al. 2011

Applied Physics Letters

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International audienceZnO nanocrystals with various sizes were prepared and characterized. Their photoluminescence dynamics has been investigated at low temperatures. For the smallest particles (3 nm), a defect-induced long-lived photoluminescence occurs around 2.5 eV which is slowed down at decay times longer than 3 ns when sample temperature T decreases. From thermal quenching of the 2.5 eV band, the exciton dissociation energy at defect centers is estimated around ∼11.8 meV. For larger crystallites (10 and 20 nm), the ultraviolet emission observed at 3.32 eV decays in less than 85 ps and follows a Varshni law [Y. P. Varshni, Physica (Amsterdam) 34, 149 (1967)]

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Spectral-temporal luminescence properties of Colloidal CdSe/ZnS Quantum Dots in relevant polymer matrices for integration in low turn-on voltage AC-driven LEDs

et al. 2022

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This work employs spectral and spectral-temporal Photoluminescence (PL) spectroscopy techniques to study the radiative mechanisms in colloidal CdSe/ZnS Quantum Dot (QD) thin films without and with 1% PMMA polymer matrix embedding (QDPMMA). The observed bimodal transient-spectral PL distributions reveal bandgap transitions and radiative recombinations after interdot electron transfer. The PMMA polymer embedding protects the QDs during the plasma-sputtering of inorganic layers electroluminescent (EL) devices, with minimal impact on the charge transfer properties. Further, a novel TiO2-based, all-electron bandgap, AC-driven QLED architecture is fabricated, yielding a surprisingly low turn-on voltage, with PL-identical and narrow-band EL emission. The symmetric TiO2 bilayer architecture is a promising test platform for alternative optical active materials.

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Mapping emissive channels of quantum dots: Influence of size and environment on energy transfer in the time domain

Cited by 3 publications

References 29 publications

Probing the Energetic Distribution of Injected Electrons at Quantum Dot–Linker–TiO₂ Interfaces

Probing the Energetic Distribution of Injected Electrons at Quantum Dot–Linker–TiO₂ Interfaces

Temperature and size dependence of time-resolved exciton recombination in ZnO quantum dots

Spectral-temporal luminescence properties of Colloidal CdSe/ZnS Quantum Dots in relevant polymer matrices for integration in low turn-on voltage AC-driven LEDs

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Mapping emissive channels of quantum dots: Influence of size and environment on energy transfer in the time domain

Cited by 3 publications

References 29 publications

Probing the Energetic Distribution of Injected Electrons at Quantum Dot–Linker–TiO2 Interfaces

Probing the Energetic Distribution of Injected Electrons at Quantum Dot–Linker–TiO2 Interfaces

Temperature and size dependence of time-resolved exciton recombination in ZnO quantum dots

Spectral-temporal luminescence properties of Colloidal CdSe/ZnS Quantum Dots in relevant polymer matrices for integration in low turn-on voltage AC-driven LEDs

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Product

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About

Probing the Energetic Distribution of Injected Electrons at Quantum Dot–Linker–TiO₂ Interfaces

Probing the Energetic Distribution of Injected Electrons at Quantum Dot–Linker–TiO₂ Interfaces