In this study we introduce a new method for the one-pot synthesis of core/shell/shell alloyed Cd1-xZnxSe/ZnSe/ZnS QDs and examine the effect of the shell coating on the optical properties and exciton dynamics of the alloy core. The photoluminescence (PL) quantum yield is greatly enhanced after shell growth, from 9.6% to 63%. The exciton dynamics were studied by time correlated single photon cou...

Semiconductor Quantum dots (QDs) have raised great attention because of their superior optical properties and wide utilization in biological and biomedical studies. More recently, there have been intense concerns on cytotoxicity assessment of QDs. Most QDs are made of heavy metal ions (e.g., Cd(2+)), which may result in potential in vitro toxicity that hampers their practical applications. In t...

A microwave-assisted synthetic procedure is presented for the preparation of low-toxic Mn:ZnSe/ZnS core/shell nanocrystals to label antibodies for selective detection of human immunoglobulin G (IgG) based on fluorescence resonance energy transfer (FRET) between the Mn:ZnSe/ZnS and Au nanoparticles (AuNPs).

Here we report a biomimetic method to synthesize core-shell CdSe/ZnS semiconductor nanocrystals using a bi-functional peptide; the resulting nanocrystals had a defect free crystallinity and a clearly observed core-shell structure; the results are significant as this is the first report of core-shell semiconductor nanocrystal synthesis using a peptide template.

Quantum dot white light-emitting diodes (QD-WLEDs) were fabricated from green- and red-emitting AgInS₂/ZnS core/shell QDs coated on GaN LEDs. Their electroluminescence (EL) spectra were measured at different currents, ranging from 50 mA to 400 mA, and showed good color stability. The modulation bandwidth of previously prepared QD-WLEDs was confirmed to be much wider than that of YAG:Ce phosphor...

InP-based quantum dots (QDs) have attracted much attention for use in optical applications, and several types of QDs such as InP/ZnS, InP/ZnSeS, and InP/GaP/ZnS have been developed. However, early synthetic methods that involved rapid injection at high temperatures have not been able to reproducibly produce the required optical properties. They were also not able to support commercialization ef...

We experimentally confirm the existence of the radial breathing mode in CdSe nanorods by Raman spectroscopy, which was deduced from ab initio calculations of the vibrational properties of bare CdSe nanowires and CdSe/ZnS core-shell nanowires. We calculated the modes' frequency for various diameters and measured a set of bare CdSe nanorods and CdSe/ZnS core-shell nanorods to determine the diamet...

ZnO-CdS, ZnO-ZnS, and ZnO-Ag2S core-shell heterojunction structures were fabricated using low-temperature, facile and simple aqueous solution approaches. The polycrystalline sulfide shells effectively enhance the field emission (FE) properties of ZnO nanowires arrays (NWAs). This results from the formation of the staggered gap heterointerface (ZnO-sulfide) which could lead to an energy well at ...

Recently, the synthesis of low-toxic quantum dots (QDs) and their application in biomedicine have attracted considerable attention. ZnSe nanocrystals doped with Mn ions which do not contain any Class A element (Cd, Pb, and Hg) can be used as a new generation of luminescent nanocrystals due to their strong dopant emission. In 2001, Norris et al. presented an organometallic synthetic route for th...

We report a synthesis of highly luminescent (CdSe)ZnS composite quantum dots with CdSe cores ranging in diameter from 23 to 55 Å. The narrow photoluminescence (fwhm e 40 nm) from these composite dots spans most of the visible spectrum from blue through red with quantum yields of 30-50% at room temperature. We characterize these materials using a range of optical and structural techniques. Optic...