in this paper, the electronic eigenstates and energy spectra of single and two-interacting electrons confined in a concentric double quantum rings with a perpendicular magnetic field in the presence of         on-center donor and acceptor impurities are calculated using the exact diagonalization method. for a single electron case, the binding energy of on-center donor and acceptor impurities ar...

the present work deals with the synthesis and characterization of cds nanoparticles with good thermal stability and optical properties by a novel and simple synthetic route. the nanoparticles were synthesized via chemical precipitation method in a single reaction vessel under ambient conditions. the prepared cds nanoparticles were compared with the bulk cds. the optical properties were determin...

Molecular beam epitaxy of InAs/GaAs quantum dots and their subsequent transformation to quantum rings by postepitaxy thermal annealing have been investigated. Photoconductive detectors with multiple quantum ring layers in the active region exhibit dark current density 10−8 A /cm2 at a bias of 2 V at 4.2 K. The rings have a single bound state, and emission of photoexcited carriers gives rise to ...

quantum dots of cds with hexagonal phase were prepared at relatively low temperature (60 oc) and short time by micro-emulsion (o/w) under ultrasound. this study was focused on the particle size distribution and the growth kinetics. the particle size distribution obtained from the optical absorption edge. it was relatively symmetrical with sonication time. in addition, an agreement was observed ...

In some recent papers Li, Voskoboynikov, Lee, Sze and Tretyak suggested an iterative scheme for computing the electronic states of quantum dots and quantum rings taking into account an electron effective mass which depends on the position and electron energy level. In this paper we prove that this method converges globally and linearly in an alternating way, i.e. yielding lower and upper bounds...

recent investigations have been shown that inorganic nanomaterials including gold nanoparticles, nonporous and mesoporous silica nanoparticles, magneticnanoparticles, and quantum dots have shown great potential in bioimaging, targeted drug delivery, and cancer therapies. biocompatibility, ease of synthesis, and ease of surface functionalization are among the significant properties of nonporous ...

The acid oxidation of carbon nanotube generally results in opening the close ends of the nanotube and to make surface modifications. Herewith, Multiwall carbon nanotubes (MWCNTs) were oxidized in acids at high temperature experimental conditions which led to the formation of graphene quantum dots (GQDs).   High resolution transmission electron microscope (HRTEM), energy dispersive X-ray spectro...