in this study un-doped and eu-doped zno nanorods and microrads were fabricated by chemical vapor deposition (cvd) method. the effects of annealing, synthesis temperature and structure on structural and photoluminescence properties of eu-doped zno samples were studied in detail. prepared samples were characterized using x-ray diffraction (xrd), scanning electron microscopy (sem), particle size a...

We consider the microstructure evolution of a nonequilibrium system of primary defects, in which mobile point defects, vacancy loops, and sessile interstitial clusters are continuously produced by cascade-damage irradiation. It is shown that in a fully annealed metal, a spatially homogeneous microstructure may become unstable if the yield of vacancy clusters in collision cascades is sufficientl...

In this paper we report on the positron lifetime results obtained for brown and colourless natural diamond. Optical effects of the observed vacancy defects in brown, high pressure, high temperature (HPHT) treated colourless and naturally colourless type IIa diamond samples were studied by combining the positron measurement with monochromatic illumination. Brown diamond was found to contain opti...

In order to investigate the nature of defects produced by ion irradiation through a heterostructure, a silicon-on-insulator substrate with a buried SiO2 layer at a depth of ;1.5 mm was irradiated. The implantation was done using 2 MeV Si ions in the dose range of 0.2– 1310 cm. The subsequent defect analysis was performed using the Au labeling technique. Besides the presence of an expected exces...

Vapor phase transport (VPT) assisted by mixture of methanol and acetone via thermal evaporation of brass (CuZn) was used to prepare un-doped and Al-doped zinc oxide (ZnO) nanostructures (NSs). The structure and morphology were characterized by field emission scanning electron microscopy (FESEM) and x-ray diffraction (XRD). Photoluminescence (PL) properties of un-doped and Al-doped ZnO showed si...

An experimental method of studying shifts between concentration-versus-depth profiles of vacancyand interstitial-type defects in ion-implanted silicon is demonstrated. The concept is based on deep level transient spectroscopy measurements utilizing the filling pulse variation technique. The vacancy profile, represented by the vacancy–oxygen center, and the interstitial profile, represented by t...

A ll solids at finite temperatures contain point defects such as vacancies and interstitials. Even at very low concentrations, such defects have a pronounced effect on the transport properties (e.g., electronic) of otherwise pure crystals. However, the effect of point defects on the thermodynamic properties of crystals is small, simply because the mole-fraction of defects is low—at least, in on...

First principles calculations have been performed to investigate the ground state properties of freestanding monolayer hexagonal boronitrene (h-BN). We have considered monolayers that contain native point defects and their complexes, which form when the point defects bind with the boron vacancy on the nearest neighbour position. The changes in the electronic structure are analysed to show the e...