Photoluminescence Intermittency from Single Quantum Dots to Organic Molecules: Emerging Themes

Riley, Erin A.; Hess, Chelsea M.; Reid, Philip J.

doi:10.3390/ijms131012487

Cited by 36 publications

(42 citation statements)

References 125 publications

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“…1,2 At the single molecule level, the fluorescence emission of these structures fluctuates in intensity but a complete dark state is never reached. Even if blinking properties of nanocrystals (NCs) are complex phenomena 3,4 that cannot be solely explained by a fast Auger recombination in charged NCs 5 and may involve multiple recombination centers, 6,7 it was shown that the blinking inhibition in CdSe/CdS NCs resulted from a reduction of the Auger recombination efficiency. While in regular CdSe/ZnS NCs the Auger lifetime scales as the volume of the emitter and is usually of the order of 10-100 ps, 8,9 in the case of thick-shell CdSe/CdS NCs, Auger lifetimes in the range of tens of nanoseconds have been measured.…”

Section: Introductionmentioning

confidence: 99%

Blinking suppression and biexcitonic emission in thick-shell CdSe/CdS nanocrystals at cryogenic temperature

et al. 2014

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The fluorescence of single colloidal thick-shell CdSe/CdS nanocrystals (NCs), at cryogenic temperature (4 K) and room temperature (RT), is studied using the intensity autocorrelation function (ACF) and lifetime measurements. The radiative and Auger decay rates corresponding to the desexcitation of the charged biexcitonic state are determined through an original method of photon postselection. Especially, the charged biexciton quantum yield increases from about 15% at RT to 60% at 4 K. The high inhibition of Auger recombination already observed for the trion state of CdSe/CdS NCs at low temperature is also demonstrated for the charged biexcitonic state. At 4 K, the ACF is equal to 1 for time scales ranging from 50 ns to 200 ms. In contrast with RT operation, the intensity of the trion emission is then perfectly stable and no blinking is observed. All the results highlight the strong confinement of the charge carriers in the CdSe core.

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Section: Introductionmentioning

confidence: 99%

Blinking suppression and biexcitonic emission in thick-shell CdSe/CdS nanocrystals at cryogenic temperature

et al. 2014

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“…Blinking dynamics are commonly investigated by analysis of the probability of a certain length of on‐ and off‐times during a blinking time trace by setting an intensity threshold between PL on‐ and off‐intensities . The general finding is that the probabilities for both times can be tentatively described by a power law often truncated by an exponential cut‐off as described for on‐times in Equation .

P_{o n} \sim {t_{o n}}^{- α} \cdot \exp true(- Γ_{normalo normaln} t_{normalo normaln} true)

…”

Section: Resultsmentioning

confidence: 99%

“…Intermittency or blinking of luminescence intensities of single quantum objects such as semiconductor quantum dots (QDs), dye molecules, fluorescent proteins, and color centers is a commonly observed phenomenon . Surprisingly, the time scale of these phenomena covers several orders of magnitude from microseconds to hours for one and the same quantum object.…”

Section: Introductionmentioning

confidence: 99%

Correlation of Intermittency of Quantum Dot Photoluminescence Intensity, Decay Time, and Energy

Göhler

Schmidt

Krasselt

et al. 2018

Physica Status Solidi (b)

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Intermittency of photoluminescence (PL) intensity is a common feature of semiconductor quantum dots (QDs). Here, we show for ZnS capped CdSe QDs that the intermittency (blinking) is closely correlated to the intermittency of PL decay times. Furthermore, we find that fluctuations of PL emission energies are also correlated with intensity and decay time blinking. The origin of energy fluctuations is a combination of switching either between energies of electronic states intrinsic to differently charged QDs or correspondingly Stark shifted states caused by slow fluctuations of the QD interface. By the method of change point analysis we assign the distribution of PL intensities intermediate between on/off intensities to distinct intermittent PL decay times and PL energies. Intermittency occurs on slow time scales between sub-ms and minutes and depends strongly on the embedding matrix. Highly specific experiments allow for identification of a distribution of charged and non-charged states near to the excitonic band edge. Most of the blinking phenomena are observed on the depopulation pathways of the band edge states. However, also population pathways are intermittent, but on a much shorter time scale. We assign this mechanism to creation of hot electrons followed by charge trapping and release at the QD interface.

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“…Their long lifetimes (on the order of 10–40 ns) increase the probability of absorption at shorter wavelengths and produce a broad absorption spectrum. Furthermore, QD emission wavelengths are size‐tunable , and researchers have shown enormous interest in and focus on the synthesis , photophysical property characterization , and bioconjugation of QDs .…”

Section: Ce Separations Of Nanomaterialsmentioning

confidence: 99%

Capillary electrophoresis and nanomaterials – Part I: Capillary electrophoresis of nanomaterials

Adam

Vaculovičová

2017

Electrophoresis

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Nanomaterials are in analytical science used for a broad range of purposes, covering the area of sample pretreatment as well as separation, detection, and identification of target molecules. This part of the review covers capillary electrophoresis (CE) of nanomaterials and focuses on the application of CE as a method for characterization used during nanomaterial synthesis and modification as well as the monitoring of their properties and interactions with other molecules. The heterogeneity of the nanomaterial family is extremely large. Depending on different definitions of the term Nanomaterial/Nanoparticle, the group may cover metal and polymeric nanoparticles, carbon nanomaterials, liposomes and even dendrimers. Moreover, these nanomaterials are usually subjected to some kind of surface modification or functionalization, which broadens the diversity even more. Not only for purposes of verification of nanomaterial synthesis and batch-to-batch quality check, but also for determination the polydispersity and for functionality characterization on the nanoparticle surface, has CE offered very beneficial capabilities. Finally, the monitoring of interactions between nanomaterials and other (bio)molecules is easily performed by some kind of capillary electromigration technique.

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Photoluminescence Intermittency from Single Quantum Dots to Organic Molecules: Emerging Themes

Cited by 36 publications

References 125 publications

Blinking suppression and biexcitonic emission in thick-shell CdSe/CdS nanocrystals at cryogenic temperature

Blinking suppression and biexcitonic emission in thick-shell CdSe/CdS nanocrystals at cryogenic temperature

Correlation of Intermittency of Quantum Dot Photoluminescence Intensity, Decay Time, and Energy

Capillary electrophoresis and nanomaterials – Part I: Capillary electrophoresis of nanomaterials

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