Ab initio computational studies were performed for CdSe nanocrystals (NCs) over a wide variety of sizes ranging from 8 to 150 atoms in conjunction with recent experimental work. The density functional based calculations indicate substantial relaxations. Changes in coordination of surface atoms were found to play a crucial role in determining the NC stability and optical properties. While optima...

In this paper we consider electromagnetic field quantization in the presence of a dispersive and absorbing semiconductor quantum dot. By using macroscopic approach and Green's function method, quantization of electromagnetic field is investigated. Interaction of a two-level atom , which is doped in a semiconductor quantum dot, with the quantized field is considered and its spontaneous emission ...

An yttria stabilised zirconia which exhibits a coreshell microstructure was investigated as a method to produce a zirconia with high ionic conductivity and improved thermal shock resistance. Zirconia grains consist of an outer shell of tetragonal zirconia with an inner core of monoclinic phase zirconia. Impedance spectroscopy was used to identify the e€ect of processing conditions on the grain ...

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...

the electronic conductance at zero temperature through a quantum wire with side-connected asymmetric quantum ring (as a scatter system) is theoretically studied using the non-interacting hamiltonian anderson tunneling method. in this paper we concentrate on the configuration of the quantum dot rings. we show that the asymmetric structure of qd-scatter system strongly influences the amplitude an...

In order to implement an integrated optical quantum circuit, designing waveguides based on the quantum box is of prime importance. To do this we have investigated optical waveguide both with and without optical pumping. The rate of absorption and emission using an array of AlGaAs/GaAs quantum box core/shell structure in the optical waveguide with various pumping intensities has computed. By con...

Photoelectrode made of nanocable structure of ZnO nanorods (NR) coated with TiO(2) nanosheets (NSs) was investigated for CdS/CdSe quantum dot co-sensitized solar cells. ZnO NRs prepared solution reaction at 60 °C served as the backbone for direct electron transport in view of the single crystallinity of the ZnO NRs and the high electron mobility of ZnO semiconductor. Anatase TiO(2) NSs with the...

The core-shell hybrid structure is the simplest motif of two-component systems which consists of an inner core coated by an outer shell. Core-shell composite materials are attractive for their biomedical, electronic and catalytic applications in which interface between core and shell is critical for various functionalities. However, it is still challenging to study the exact role that interface...

Quantum dot cellular automata (QCA) introduces a pioneer technology in nano scale computer architectures. Employing this technology is one of the solutions to decrease the size of circuits and reducing power dissipation. In this paper, two new optimized FlipFlops with reset input are proposed in quantum dot cellular automata technology. In addition, comparison with related works is performed.Th...

CdSe quantum dots were in situ deposited on various structures of TiO2 photoanode by successive ionic layer adsorption and reaction (SILAR). Various sensitized TiO2 structures were integrated as a photoanode in order to make quantum dot sensitized solar cells. High power conversion efficiency was obtained; 2.89 % (Voc=524 mV, Jsc=9.78 mA/cm2, FF=0.56) for the cells that sensitized by SILAR meth...