We provide a microscopic theory for semiconductor quantum dots that explains the pronounced deviations from the prevalent point-dipole description that were recently observed in spectroscopic experiments on quantum dots in photonic nanostructures. The deviations originate from structural inhomogeneities generating a large circular quantum current density that flows inside the quantum dot over m...

chemical precipitation method was used in order to synthesize cdse:ag quantum dots (2-3 nm). their physical properties and characteristics were assessed by x-ray diffraction, ultra violet-visible spectrophotometer and tem (transmission electron microscope) and it was shown that the obtained cdse:ag quantum dots are cubic with high-quality. antibacterial effects of cdse:ag nanoparticles against ...

glucose, as the major energy source in cellular metabolism, plays an important role in the natural growth of cells. herein, a simple, rapid and low-cost method for the glucose determination by utilizing glucose oxidase and cdte/thioglycolic acid (tga) quantum dots (qds) on a thin layer chromatography (tlc) plate has been described. the detection was based on the combination of the glucose enzym...

Polar optical-phonon modes are derived analytically for spheroidal quantum dots with wurtzite crystal structure. The developed theory is applied to freestanding spheroidal ZnO quantum dots and to spheroidal ZnO quantum dots embedded into a MgZnO crystal. The wurtzite (anisotropic) quantum dots are shown to have strongly different polar optical-phonon modes in comparison with zincblende (isotrop...

Quantum dots realized in InAs are versatile systems to study the effect of spin-orbit interaction on the spin coherence, as well as the possibility to manipulate single spins using an electric field. We present transport measurements on quantum dots realized in InAs nanowires. Lithographically defined top-gates are used to locally deplete the nanowire and to form tunneling barriers. By using th...

What makes three dimensional semiconductor quantum nanostructures so attractive is the possibility to tune their electronic properties by careful design of their size and composition. These parameters set the confinement potential of electrons and holes, thus determining the electronic and optical properties of the nanostructure. An often overlooked parameter, which has a...

In the present work, an extensive theoretical calculation study on Histidine-Histidine dipeptide in gas phase is done by using DFT method with Gaussian 98 program. Through investigations on the molecular geometries of this molecule it is found that there is six rings in the molecules not two rings. The presence of four intramolecular hydrogen bonds is responsible for the formation of additional...

BACKGROUND The purpose of this study was to elucidate the mechanism of natural uptake of nonfunctionalized quantum dots in comparison with microinjected quantum dots by focusing on their time-dependent accumulation and intracellular localization in different cell lines. METHODS The accumulation dynamics of nontargeted CdSe/ZnS carboxyl-coated quantum dots (emission peak 625 nm) was analyzed i...

BACKGROUND Quantum dots (qdots) are a promising alternative to organic fluorophores for biological imaging. Advantages of quantum dots over organic fluorophores include broad excitation coupled with narrow, tunable emission, high resistance to chemical and metabolic degradation, a higher photobleaching threshold and finally the ability to be modified with a targeting ligand. These many properti...

The paper presents a survey of literature on the structure and optical properties of ZnS and copper ion-doped ZnS quantum dots. The effect of other metal dopants on the spectral properties of ZnS:Cu quantum dots was also considered. The influence of such parameters as dopant concentration, temperature of the synthesis and compounds which form or modify the additional layer on dots on spectral p...