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The structural and optical properties of Co-doped ZnO thin films prepared by a sol-gel dip-coating method were investigated. X-ray diffraction analysis showed that the thin films were grown with a c-axis preferred orientation. The position of the (002) peak was almost the same in all samples, irrespective of the Co concentration. It is thus clear that Co(More)
The power- and temperature-dependent photoluminescence properties of Al-doped ZnO nanorod array thin films grown by the hydrothermal method were investigated. The intensities of both the near-band-edge emission (NBE) and deep-level emission (DLE) as well as the overall spectral line shape were strongly affected by the excitation power. At low excitation(More)
This study focuses on the effect of annealing the Au seed layer (ASL) on the structural and optical properties of electrodeposited ZnO nanorods. ZnO nanorods were fabricated in a three-step approach. In the first step, ASLs were deposited using an ion sputter technique. In the second step, layers were annealed in air at various temperatures ranging from 400(More)
Metal catalyst-free ZnO nanorods were grown on PS with buffer layers grown at 450 degrees C by plasma-assisted molecular beam epitaxy. Room temperature and temperature-dependent photoluminescence were carried out to investigate the optical properties of the ZnO nanorods with the average diameter of 120 nm and length of 300 nm. Three emission peaks, free(More)
ZnO seed layers were deposited onto a quartz substrate using the sol--gel method, and Al-doped ZnO (AZO) nanorod array thin films with different Al concentrations that ranged from 0 to 2.0 at. % were grown on the ZnO seed layers via the hydrothermal method. Optical parameters, including the optical band gap, the absorption coefficient, the Urbach energy,(More)
In this study, we report a novel regrowth method of sol-gel-prepared ZnO films using a vapor-confined face-to-face annealing (VC-FTFA) technique in which mica was inserted between two films, followed by annealing with the FTFA method. The ZnO nanorods are regrown when zinc acetate dihydrate and zinc chloride (ZnCl2) are used as the solvent, because these(More)
ZnO nanorods were grown on MgxZn1-xO seed layers with different content ratio ranging from 0 to 0.3 by hydrothermal method. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and photoluminescence (PL) were carried out to investigate the effects of Mg content ratio for the MgxZn1-xO seed layers on the structural and optical properties of the ZnO(More)
Sol-gel spin-coating was used to deposit ZnO seed layers onto quartz substrates, and ZnO nanorods doped with various concentrations of B (i.e., BZO nanorods) ranging from 0 to 2.0 at% were hydrothermally grown on the ZnO seed layers. The effects of B doping on the absorption coefficient, optical band gap, Urbach energy, refractive index, extinction(More)
This paper addresses the problem of efficient processing a large set of proximity monitoring queries. Many location-based applications are enabled by handling many moving queries over mobile objects. Efficient processing of such queries mainly relies on effective probing because it needs a huge amount of distance-based comparison. To reduce processing time,(More)
This paper addresses the problem of efficient processing of continuous range queries over moving objects. Existing server-centric methods increase the server workload and entail a huge amount of communication cost when the number of moving objects is enormous. To remedy the problem of the existing server-centric methods, we propose a new distributed method,(More)
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