Ruziana Mohamed

Effect of annealing temperature of magnesium doped zinc oxide nanorods growth on silicon substrate

Magnesium (Mg)-doped zinc oxides (ZnO) have been prepared on a silicon substrate by using the solution-immersion method. The nanorods films were annealed at different temperature 0°C, 250°C, 500°C respectively for 1 hour. The XRD diffraction indicated that the Mg-doped ZnO nanorods have good crystallinity with a hexagonal wurzite structure preferentially oriented along the (002) direction. PL spectroscopy at room temperature shows strong UV peaks appearing at 383 nm when annealed at 250°C. The intensity of broad emission peaks increases with increasing annealing temperature to 500°C which is possibility attributed to intrinsic defects.

Thickness-controlled synthesis of vertically aligned c-axis oriented ZnO nanorod arrays: Effect of growth time via novel dual sonication sol–gel process

Zinc-oxide (ZnO) nanorod arrays were successfully prepared by using dual sonication sol–gel process. Field emission scanning electron microscopy revealed that the nanorods exhibited a hexagonal structure with a flat-end facet. The nanorods displayed similar surface morphologies and grew uniformly on the seed layer substrate, with the average diameter slightly increasing to the range of 65 to 80 nm after being immersed for varying growth times. Interestingly, thickness measurements indicated that the thicknesses of the samples increased as the growth time was extended. In addition, the X-ray diffraction spectra indicated that the prepared ZnO nanorods with a hexagonal wurtzite structure grew preferentially along the c-axis. Therefore, we can conclude that the diameter, length, and orientation of the ZnO nanorod arrays along the c-axis are controllable by adjusting the growth time, motivating us to further explore the growth mechanisms of ZnO nanorods.

Electrically conductive nanostructured silver doped zinc oxide (Ag:ZnO) prepared by solution-immersion technique

p-type ZnO films have been fabricated on ZnO-seeded glass substrate, using AgNO3 as a source of silver dopant by facile solution-immersion. Cleaned glass substrate were seeded with ZnO by mist-atomisation, and next the seeded substrates were immersed in Ag:ZnO solution. The effects of Ag doping concentration on the Ag-doped ZnO have been investigated. The substrates were immersed in different concentrations of Ag dopant with variation of 0, 1, 3, 5 and 7 at. %. The surface morphology of the films was characterized by field emission scanning electron microscope (FESEM). In order to investigate the electrical properties, the films were characterized by Current-Voltage (I-V) measurement. FESEM micrographs showed uniform distribution of nanostructured ZnO and Ag:ZnO. Besides, the electrical properties of Ag-doped ZnO were also dependent on the doping concentration. The I-V measurement result indicated the electrical properties of 1 at. % Ag:ZnO thin film owned highest electrical conductivity.

Effect of annealing temperature on the morphology and optical properties of PMMA films by spin-coating method

Poly(methyl methacrylate) (PMMA) films were deposited on glass substrate by sol-gel spin-coating method. The films were annealed for 10 minutes in furnace at different annealing temperature of room temperature, 50, 100, 150 and 200 °C. The effect of annealing temperatures to the surface and optical properties of PMMA films spin-coated on the substrate were investigated by Atomic Force Microscope (AFM) and Ultraviolet-Visible (UV-Vis) Spectroscopy. It was observed in AFM analysis all the annealed films show excellent smooth surface with zero roughness. All the samples demonstrate a high transmittance of 80% in UV region as shown in UV-Vis measurement. Highly transparent films indicate the films are good optical properties and could be applied in various optical applications and also in non-linear optics.

The Influence of Immersion Time to the Optical properties of ZnO Growth on PMMA-coated Substrate by Solution- Immersion Method

We present the growth of ZnO on PMMA-coated substrate under influence of different immersion time by solution-immersion technique. PMMA polymer was coated on the substrate by spin-coating method. The PMMA-coated substrate was then prepared for non- immersed and immersed for four (4) and six (6) hours in zinc solution. The optical properties of the film obtained were characterized using Photoluminescence (PL), Raman Spectra and Ultraviolet-Vis (UV-Vis) spectroscopy. It was found that shorter time of immersion (4 hours) produced higher intensity of PL and Raman. However, the reverse was found for UV-Vis measurement. The low absorption that was shown from the film immersed for 4 hours may correspond to the random distribution and orientation of ZnOparticle growth on PMMA-coated substrate.

Low Temperature Growth and Optical Properties of Zinc Oxide Nanostructure Prepared by Two-Step Solution-Based Deposition Method

ZnO thin films with typical c-axis (0 0 2) orientation were successfully deposited on glass substrates by two-step deposition method; mist-atomization and solution-immersion. The samples were annealed at selected temperature range of 350-500 ᵒC. The prepared samples then analyzed by Raman spectroscopy and photoluminescence (PL) spectroscopy. The optical properties of the samples were studied. The results of different annealing temperatures are also compared to investigate the optical and physical properties of each sample. Photoluminescence (PL) spectra showed low intensity in UV emission and high intensity in the visible emission, which indicates a good surface morphology of the ZnO nanorod. The Raman intensity changes in all sample were also tested.

Influence of Annealing Temperature to Surface Morphology of Flowerlike ZnO Deposited on Seeded Glass

Flower-shaped ZnO nanocrystals have been synthesized by a two-step solution based deposition method; mist-atomizer and solution-immersion on seeded glass substrate. The samples are annealed at different temperature in the range of 350 to 500 ᵒC. The structural properties of the samples were studied. Field emission scanning electron microscopy (FESEM) micrograph and atomic force microscopy (AFM) images for the ZnO thin films were obtained. Morphological changes due to various annealing temperature are discussed as changes observed in the ZnO crystals. FESEM image of the surface of the ZnO reveal the flowerlike vertical nanorods with hexagonal crossection. The samples with higher roughness analyzed from AFM images indicate that the sample have larger grain. AFM results are found in good agreement and supported the FESEM results.

The influence of growth duration process on morphology and electrical properties of SnO2 Nanostructured Films

Tin oxide (SnO2) nanostructured thin film with different immersion times was prepared on zinc oxide (ZnO) seeded catalyst using immersion method. The immersion times were varied at 3.0, 3.5 and 4.0 hours. Field emission scanning electron microscopy (FESEM) and two point probes current-voltage (I-V) measurements were used to study the surface morphology and electrical properties of SnO2 nanostructured thin films. The diameter size of SnO2 nanostructures which immersed at 3.0, 3.5 and 4.0 h were in range 10-20 nm, 20-30 nm and 30-50 nm, respectively. The results shows the highest electrical properties was at 3.0 h of immersion time.

Fabrication and characterization of Bi1.6Pb0.4Sr2Ca2Cu3-xFexOy superconductor

This paper reports the properties of Bi-2223 superconductors that had been doped with Fe2O3 at Cu-site of the system. It was prepared in bulk form using high purity oxide powders via solid state reaction technique with intermediate grinding. A series of x = 0.00, 0.02, 0.04, 0.06, 0.08 and 0.10 of Fe were stoichiometrically added to the well balanced of Bi1.6Pb0.4Sr2Ca2Cu3-xFexOy in order to trace the effect of Fe doping. Hence, electrical resistivity, X-ray diffraction and Field Emission Scanning Electron Microscopy have been carried out to assess the effects of Fe doping. These measurements indicate that Fe doping decreased the critical temperature and degrade the formation of high Tc phase compared with the undoped sample. The orthorhombicity parameters were increased due to substitution of Cu 3+ ion by Fe 2+ ion.

Morphological, Structural and Optical Properties of Mg Doped ZnO Nanostructured Growth by Aqueous Solution Method

Mg doped Zinc oxide nanorods films were successfully deposited on glass substrate prepared by aqueous solution-immersion method. The influence of annealing temperature on the nanorod films were studied at different annealing temperatures 0°C, 250°C and 500°C respectively. FESEM showed the morphology of the films with hexagonal nanorods growth. XRD results indicated the crystalline structure of ZnO doped Mg nanorods films where the peak intensity of ZnO was decreased as annealing temperature increases. Photoluminescence (PL) measurement at room temperature showed the increasing of intensity peak for visible spectra with increasing of annealing temperature.