Suppressing the Fluorescence Blinking of Single Quantum Dots Encased in N-type Semiconductor Nanoparticles

Abstract

N-type semiconductor indium tin oxide (ITO) nanoparticles are used to effectively suppress the fluorescence blinking of single near-infrared-emitting CdSeTe/ZnS core/shell quantum dots (QDs), where the ITO could block the electron transfer from excited QDs to trap states and facilitate more rapid regeneration of neutral QDs by back electron transfer. The average blinking rate of QDs is significantly reduced by more than an order of magnitude and the largest proportion of on-state is 98%, while the lifetime is not considerably reduced. Furthermore, an external electron transfer model is proposed to analyze the possible effect of radiative, nonradiative, and electron transfer pathways on fluorescence blinking. Theoretical analysis based on the model combined with measured results gives a quantitative insight into the blinking mechanism.

Quantum Light in Curved Low Dimensional Hexagonal Boron Nitride Systems

“…In addition, quantum dot research has shown ITO to suppress emission blinking due to facile electron transfer (due to ITO's Fermi level) to possible trap states, thus blocking emitter electron transfer to these states once in the excited state. 70 Due to the proximity of our nano-material to the environment, we expect a similar effect. To probe suspended material, we also used a conductive gold TEM grid.…”

“…To this end, we deposited 200 nm of indium tin oxide (ITO) on SiO 2 , rendering the substrates transparent and conductive, thus making them compatible with both types of spectroscopy. In addition, quantum dot research has shown ITO to suppress emission blinking due to facile electron transfer (due to ITO’s Fermi level) to possible trap states, thus blocking emitter electron transfer to these states once in the excited state 70 . Due to the proximity of our nano-material to the environment, we expect a similar effect.…”

Lord of The Crowns: A New Precious in the Kingdom of Clustomesogens

“…Depending on the environment and nature of the octahedral metallic scaffold, they show a stable phosphorescence in the red‐NIR with high quantum yield values that depend on their substituents (L i and L a ), a large Stoke shift and lifetimes in the microseconds range . Once their ceramic‐like behavior can be overcome, they represent realistic alternatives to rare earth luminophores needing organic antenna to become efficient emitters, lead containing hybrid perovskites, which, beside their poor photostability, possess small Stoke shifts and suffer from reabsorption, cadmium containing quantum dots that undergo photoblinking or finally organic dyes showing photobleaching . Here, we show that ceramic‐like transition metal cluster compounds can be introduced in thermotropic LC, using extremely weak supramolecular interactions between 15C5 crown ether derivatives (Figure ) and either Cs + or K + cations acting as the anionic cluster counter‐ion.…”

Construction of 3D-rendering imaging of an ischemic rat brain model using the planar FMMD technique

“…To solve the above problem, quantum dots (Qdots) have recently been employed to complement conventional fluorescent dyes 4 due to their superior photostability compared to conventional fluorescence dyes. However, Qdots also have intrinsic problems, such as photoblinking that induces fluorescence intensity fluctuations 5 , cytotoxic damage to cell functionalities 6 , and a blueshift after continuous excitation leading to a photobleached state 7 . Additionally, in the case of fluorescent markers, light needs to be able to pass through the tissue.…”