semiconductor nanoparticles exhibit size dependent properties due to quantum confinement effect that arenot present in their bulk counterparts. in this work, extremely fine and pure sno2 nanoparticles of ~1.1nm size were synthesized by a solution process, in which amorphous precipitate of sno2 was crystallizedby microwave heating. the particles sizes varied from ~1.1 to ~2.7 nm. by xrd analysis...

cd1-xmnxs (x = 0, 0.1, 0.2) nanoparticles, prepared by co-precipitation method under ultrasonic irradiation, were studied by means of x-ray diffraction, scanning electron microscopy, ftir and uv-vis  spectroscopy measurements. the average particle size of nanoparticles from the scanning electron microscopy image is about 20-30 nm. results show that partial substitution of cd by mn leads to a re...

Electrostatic ~gated! quantum dots are studied by computational methods. Electronic properties of the electrostatic quantum dots are determined by the confinement potential, which is created by external voltages, applied to the electrodes, and band offsets. We have solved the Poisson equation for the two-terminal quantum dot nanodevice made of several GaAs and AlGaAs layers and obtained the con...

We have studied the Zeeman splitting in ballistic hole quantum wires formed in a (311)A quantum well by surface gate confinement. Transport measurements clearly show lifting of the spin degeneracy and crossings of the subbands when an in-plane magnetic field B is applied parallel to the wire. When B is oriented perpendicular to the wire, no spin splitting is discernible up to B = 8.8 T. The obs...

We report the growth by ion exchange synthesis of ZnS nanoparticles in MCM-41 matrices using Zn (CH3COO)2 and Na2S starting sources. The final product (ZnS/MCM-41) was characterized by X-ray diffraction (XRD) pattern, transmission electron microscopy (TEM), scanning electron microscopy (SEM), infrared spectrometry (IR) and UV-vis spectroscopy. Its crystalline st...

Spatial and dielectric confinement modulations of the spontaneous emission rates, transition energies, and charge-density distributions of a singly ionized double donor system D2 + in a spherical quantum dot are calculated within the framework of the effective-mass envelope function approximation. Dipole moments, energy splittings, transition moments, electron-density distributions, and spontan...

Binding energies of negative sX−d and positive trions sX+d in quantum wires are studied for strong quantum confinement of carriers which results in a numerical exactly solvable model. The relative electron and hole confinement have a strong effect on the stability of trions. For equal hole and electron confinement, X+ is more stable but a small imbalance of the particle confinement towards a st...

In this work, ultrathin amorphous Ge films (2 to 30 nm in thickness) embedded in SiO2 layers were grown by magnetron sputtering and employed as proficient light sensitizer in photodetector devices. A noteworthy modification of the visible photon absorption is evidenced due to quantum confinement effects which cause both a blueshift (from 0.8 to 1.8 eV) in the bandgap and an enhancement (up to t...

In quantum systems, the presence of a disordered potential may induce the appearance of strongly localized quantum states (called Anderson localization), i.e., eigenfunctions that essentially “live” in a very restricted subregion of the entire domain. We show here that solving a simple Dirichlet problem reveals a network of interconnected lines which are the boundaries of the localization subre...

We perform magnetotransport measurements in lithographically patterned graphene nanoribbons down to a 70 nm width. The electronic spectrum fragments into an unusual Landau levels pattern, characteristic of Dirac fermion confinement. The two-terminal magnetoresistance reveals the onset of magnetoelectronic subbands, edge currents and quantized Hall conductance. We bring evidence that the magneti...