the full adders (fas) constitute the essential elements of digital systems, in a sense that they affect the circuit parameters of such systems. with respect to the mosfet restrictions, its replacement by new devices and technologies is inevitable. qca is one of the accomplishments in nanotechnology nominated as the candidate for mosfet replacement. in this article 4 new layouts are presented fo...

We demonstrate efficient electroluminescence from thin film structures containing core-shell CdSe(ZnS) quantum dots dispersed in molecular organic host materials. In the most efficient devices, excitons are created on the quantum dot sites via energy transfer from organic host molecules, and direct charge injection into the quantum dots is minimized. For quantum dots with core diameter 38 A, th...

We study the effects of bifunctional linker on the optical properties of ZnO nanocolumn-linker-CdSe quantum dots heterostructure. The CdSe quantum dots are anchored on the surface of ZnO nanocolumns through either aliphatic linker of 3-aminopropyl trimethoxysilane (APS) or aromatic linker of p-aminophenyl trimethoxysilane (APhS). X-ray photoelectron spectroscopy is used to confirm the bifunctio...

Quantum dots play a promising role in the development of novel optical and biosensing devices. In this study, we investigated steady state and time-dependent luminescence properties of InGaP/ZnS core/shell colloidal quantum dots in a solution phase at room temperature. The steady state experiments exhibited an emission maximum at 650 nm with full width at half maximum of ~ 85 nm, and strong fir...

Colloidal quantum dots offer broad tuning of semiconductor band structure via the quantum size effect. In this paper, we present a detailed investigation on the influence of the thickness of colloidal lead sulfide (PbS) nanocrystals (active layer) to the photovoltaic performance of colloidal quantum dot solar cells. The PbS nanocrystals (QDs) were synthesized in a non-coordinating solvent, 1-oc...

Ultrafast transmission changes around the fundamental trion resonance are studied after exciting a p-shell exciton in negatively charged II-VI quantum dot. The biexcitonic induced absorption reveals beats between hot states at 133 GHz. While interband dephasing is dominated by relaxation of P-shell hole within 390 fs, trionic coherence remains stored spin system for 85 ps due to Pauli blocking ...

the combined effect of hydrostatic pressure and temperature on correlation energy in a triplet state of two electron spherical quantum dot with square well potential is computed. the result is presented taking gaas dot as an example. our result shows the correlation energies are i)negative in the triplet state contrast to the singlet state ii) it increases with increase in pressure  iii)further...

While the dynamics for three-dimensional axially symmetric two-electron quantum dots with parabolic confinement potentials is in general non-separable we have found an exact separability with three quantum numbers for specific values of the magnetic field. Furthermore, it is shown that the magnetic properties such as the magnetic moment and the susceptibility are sensitive to the presence and s...