For colloidal quantum dots, the ongoing biggest problem is their fluorescence blinking. Until now, there is no generally accepted model for this fluorescence blinking. Here, two-photon excited fluorescence from CdSe/ZnS nanocrystals on silicon nitride photonic crystals is studied using a femtosecond laser. From analysis of the spectra and decay processes, most of the relative trion efficiency i...

We report an analysis method to identify conjugated ligands and their binding states on semiconductor nanocrystals based on their molecular information. Surface science techniques, such as time-of-flight secondary-ion mass spectrometry (ToF-SIMS) and FT-IR spectroscopy, are adopted based on the micro-aggregated sampling method. Typical trioctylphosphine oxide-based synthesis methods of CdSe/ZnS...

An array of Ag nanoboxes fabricated by helium-ion lithography is used to demonstrate plasmon-enhanced nonradiative energy transfer in a hybrid quantum well-quantum dot structure. The nonradiative energy transfer, from an InGaN/GaN quantum well to CdSe/ZnS nanocrystal quantum dots embedded in an ~80 nm layer of PMMA, is investigated over a range of carrier densities within the quantum well. The ...

Background Quantum dots (QDs) are new types of fluorescent materials for biological labeling. QDs toxicity study is an essential requirement for future clinical applications. Therefore, this study aimed to evaluate cytotoxic effects of CdSe: ZnS QDs on male reproductive system. MaterialsAndMethods In this experimental study, the different concentrations of CdSe: ZnS QDs (10, 20 and 40 mg/kg) we...

The results of studies the spectral-kinetic (absorption and fluorescent) characteristics polymer nanospheres created by us (containing luminescent inorganic CdSe/ZnS quantum dots photochromic diarylethene molecules) incorporated into a film are presented. A reversible modulation fluorescence intensity dots, caused photoisomerization molecules, was found. It is shown that in matrices exhibit hig...

X–ZnS quantum dots (QDs) are synthesized in aqueous solution by a simple chemical route where X represents 3-mercaptopropionic acid (MPA) or 3-mercapto-1-propanesulfonic (MPS) which two well-known low cost and stable ligands. The QDs yielded suspensions of nanoparticles with excellent monodispersity, water solubility fluorescence stability relatively high yield 11% 10% for MPA-ZnS MPS-ZnS respe...

the comparison of growth processes and fluorescent properties of cdznte semiconductor quantum dots that are synthesized in different concentrations of zn2+ in water are discussed in this paper. the samples are characterized through absorbtion (uv) and photoluminescence spectra (pl). the results show that when the reaction time is prolonged, the absorption peak and fluorescent emission peak pres...

The use of quantum dots (QDots) as bright and photostable probes for long-term fluorescence imaging is gaining more interest. Thus far, (pre)clinical use of QDots remains limited, which is primarily caused by the potential toxicity of QDots. Most QDots consist of Cd2+ ions, which are known to cause high levels of toxicity. Therefore, the cytotoxic effects of CdSe quantum dots on embryonic devel...