Papers by Author: Mohamad Hafiz Mamat

Abstract: 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.

Abstract: Tin doped zinc oxide (Sn:ZnO) thin films were prepared on glass substrates via sol-gel dip-coating technique starting from zinc acetate dehydrate, (CH₃CO₂)₂Zn⋅2H₂O and tin chloride, SnCl₂. The consequences of various Sn doping on the behavior of the film was investigated. The atomic percentages of dopant in ZnO-based solution were [Sn⁴⁺]/[Zn²⁺] which is between 0% and 4%. The thin films were characterized using Field Emission Scanning Electron Microscope (FESEM) and UV-Vis-NIR spectrophotometer.

Abstract: Tin-doped Zinc Oxide (Sn-doped ZnO) thin films were prepared using zinc nitrate hexahydrate as a starting material by sol-gel immersion method. The synthesized samples were characterized by current-voltage (I-V) measurement and Field Emission Scanning Electron Microscopy (FESEM). The Sn doping concentration were varied at 1.0 at.%, 2.0 at.%, 3.0 at.% and 4.0 at.%. FESEM images show that as the Sn concentration increased, the nanoparticles size of Sn-doped ZnO become denser and less grain boundary which might help in improvement of the electrical properties.

Abstract: Tin-doped Zinc Oxide (Sn-doped ZnO) thin films were prepared using zinc nitrate hexahydrate as a starting material by sol-gel immersion method. Then the synthesized samples were characterized by current-voltage (I-V) measurement and FESEM. The Sn doping concentration were varied at 0.2 at.%, 0.4 at.%, 0.6 at.%, 0.8 at.% and 1.0 at.%. The result suggests that the optimum value for Sn doping concentration was 0.8 at.% which exhibited the highest conductive sample with value of 3.00 ×10^-6 S/cm.

Abstract: Tin-doped Zinc Oxide (Sn-doped ZnO) thin films were prepared using zinc acetate dehydrate as a starting material by sol-gel immersion method. The doping concentrations were varied at 0 at.%, 0.5 at.%, 1.0 at.%, 2.0 at.%, 3.0 at.% and 4.0 at.%. The synthesized samples were characterized by current-voltage (I-V) measurement and UV-VISS spectrometer.

Abstract: Sol gel immersion method has been used to synthesize magnesium doped zinc oxide (Mg:ZnO) thin film on glass substrate. The morphological of annealed thin film was study using atomic force microscopy (AFM) while UV-Visible spectroscopy was used to examine the optical transmittance properties. The optical band gap was estimated by using Tauc’s method. From the results, the surface roughness was change as annealing temperature increases. The increasing of annealing temperature also affects the transmittance spectra which are shifted to lower wavelength. The optical band gaps of the thin film were varied due to different annealed temperature.

Abstract: Semiconductor ZnO nanostructure with low dimension for gas sensing has been studied due to its features such as good sensitivity, selectivity and show fast response in gas sensing detection. This attractive material could be growth in a variety nanostructure such as one-dimensional nanostructure eg; the nanorods, nanowire, nanobelts and nanotubes and two-dimensional (2D) eg; nanosheet, nanodisk and nanoflakes. ZnO can also be tuned to perform a mixture of nanostructure to improve the performance of its detection. This paper provides the report in synthesis of ZnO nanostructure with a simple method at low temperature for sensor application.

Abstract: Aluminium doped zinc oxide (Al:ZnO) thin films were prepared by a sol-gel dip coating process. In particular, the case of change of thermal annealing temperature was studied. The characterisation of the films by various analytical methods shows a correlation between thermal annealing temperature and characteristic of the film. The influence of the thermal annealing temperature on the film growth can be clearly observed. At lower thermal annealing temperatures, granular structure dominates the films, while the films feature a bigger grain growth at higher annealing temperatures. All films exhibited an average transmittance of greater than 85% in the visible region, with absorption edges at ~380 nm.

Abstract: Multilayered thin films of aluminum-doped ZnO (Al:ZnO) have been deposited by the sol-gel dip coating technique. Experimental results indicated that the thermal annealing temperature affected the crystallinity of the Al:ZnO films. X-ray diffraction (XRD) analysis showed that thin films were preferentially orientated along the c-axis plane. The preferred orientation along (0 0 2) plane becomes more pronounced as the thermal annealing being increased. The film thickness ranges between 180 and 690 nm. In our experiments, the most optimum condition of Al:ZnO annealing temperature was both 500 oC.

Abstract: Research innovation in finding new carbon sources for carbon nanostructured material production was intensively done lately. In this review, we present the production of carbon nanostructures such as carbon fibers, nanotubes, nanowhiskers, microspheres and porous carbon from several waste materials. The benefit of the use of waste materials such as waste cooking palm oil, chicken fat, waste natural oil, glycerol, printed circuit board, plastic wastes, waste engine oil, scrap tyre, heavy oil residue and deoiled asphalt is not only in the term of their environmentally friendly approach but also the economic value to reduce the high cost of carbon material production using common sources. On the other hand, these materials are easy access sources and can be alternative utilization to convert waste materials into high value nanomaterials.