The synthesis of Mg-doped ZnO nanocrystals was employed as a model system to quantitatively study the chemical kinetics of the precursor conversion reactions at synthetic conditions and the correlations with the formation of doped nanocrystals. An accurate method using Fourier transform infrared spectroscopy was developed to explore the alcoholysis reactions of the cationic precursors. Our stud...

Methods for introducing new magnetic, optical, electronic, photophysical, or photochemical properties to semiconductor nanocrystals are attracting intense applications-oriented interest. In this communication, we report the preparation and electronic absorption spectroscopy of colloidal ZnO DMS-QDs. Our synthetic procedure involves modification of literature methods known to yield highly crysta...

In this study, we synthesized various dimensionalities of ZnO nanowires using the Ti grid-assisted chemical vapor deposition process. Energy dispersive X-ray spectroscopic mapping technique accompanied with a lattice diffusion model was used to characterize the growth mechanism. A diffusion ratio γ, defined by short-circuit and lattice diffusion activation energies, was obtained to describe the...

We report a method for the preparation of colloidal ZnO-diluted magnetic semiconductor quantum dots (DMS-QDs) by alkaline-activated hydrolysis and condensation of zinc acetate solutions in dimethyl sulfoxide (DMSO). Mechanistic studies reveal that Co(2+) and Ni(2+) dopants inhibit nucleation and growth of ZnO nanocrystals. In particular, dopants are quantitatively excluded from the critical nuc...

Pulsed laser ablation in liquid was employed to synthesize zinc oxide (ZnO) nanocolloidal suspension. Colloidal ZnO nanocrystals are synthesized by pulsed laser ablation of high purity zinc target in double distilled water with various laser fluences at RT. UV–visible absorption and transmission electron microscope are used for the characterization of colloidal ZnO nanoparticles (NPs). The opti...

We derive analytically the interface and confined polar optical-phonon modes for spherical quantum dots with wurtzite crystal structure. While the frequency of confined optical phonons in zincblende nanocrystals is equal to that of the bulk crystal phonons, the confined polar optical phonons in wurtzite nanocrystals are shown to have a discrete spectrum of frequencies different from those in bu...

With the rapid developments in nanotechnology, there has been tremendous interest in ZnO-related nanomaterials because ZnO is a wide band-gap semiconductor and a piezoelectric oxide. As a result, it is useful for optoelectronics, transparent electronics, sensors, and transducers. ZnO crystals have a noncentral symmetric wurtzite structure and are composed of close packed O and Zn2þ layers piled...

Lowering the working temperature without sacrificing other good gas-sensing properties is of particular interest to gas sensors for an excellent performance. In this work, La surface doped ZnO nanocrystals were successfully prepared by a facile thermal treatment with lanthanum nitrate (La(NO3)3) solution injected into ZnO thick films, which exhibited a remarkable decrease in the optimal working...

ZnO nanocrystals were successfully fabricated by wet-chemical method. Optical properties of excitons confined in ZnO nanocrystals were studied by measuring both optical absorption and photoluminescence spectra. Absorption due to free excitons was clearly observed whereas strong PL lines were recorded in the UV region at around the exciton absorption energy. Red-shift of optical features with in...

Surface x-ray diffraction experiments reveal that, in cobalt-doped ZnO films two to five monolayers thick, Wurtzite-type CoO nanocrystals are coherently embedded within a hexagonal boron-nitride- (h-BN)-type ZnO matrix, supporting the model of a phase separation. First-principles calculations confirm that, in contrast with ZnO, the formation of h-BN-type CoO is unfavorable in the ultrathin film...