Sharul Ashikin Kamaruddin

Zinc oxide microrods prepared by sol-gel immerse technique

Purpose – Zinc oxide (ZnO) is an emerging optoelectronic material due to its various functional behaviors. The purpose of this paper is to report on the fabrication and characterizations of ZnO microrods.Design/methodology/approach – ZnO microrods were synthesized using sol‐gel immerse technique on oxidized silicon (Si) substrates. The oxidized Si substrates were immersed in ZnO aqueous solution for different times ranging from three to five hours. The surface morphologies of the ZnO microrods were examined using scanning electron microscope (SEM). In order to investigate the structural properties, the ZnO microrods were measured using an X‐ray diffractometer (XRD). The optical properties were measured using a photoluminescence (PL) spectrophotometer.Findings – Characterization from SEM shows an enhanced growth of the ZnO rods with increasing immerse time. XRD characterizations demonstrate sharp and narrow diffraction peaks peculiar to ZnO, which implies that the rod is of high crystallinity. Based on the...

Surface Morphology and Optical Properties of ZnO Films Synthesis Using Different Solvent

Zinc oxide (ZnO) is a promising electronic material for a variety of large area electronic applications including thin-film sensors, transistors, and solar cells. Various techniques have been focused and explored to synthesize ZnO films. In this study, sol-gel process was adopted as the fabrications process to grow the ZnO films. Three different types of solvents were used including ethanol, isopropanol and ethylene glycol as the reaction medium in the ZnO solution. The correlation between different solvents used and the properties of the ZnO films was explored and observed. The surface morphologies, structural and optical properties were examined using field émission scanning electron microscope (FESEM), X-ray diffractometer (XRD) and ultraviolet-visible (UV-Vis) spectroscopy. Through the observation from FESEM results, the surface morphology changed when different solvents were used. The crystallographic structures of the ZnO films demonstrate high crystallinity, and the extracted crystallite size is around 30 nm. Furthermore, ZnO films synthesized using isopropanol and ethylene glycol exhibit high transmittance spectra greater than 80% in the visible region. In general, the experimental results revealed that different solvents in the sol-gel process exert influences on the properties of the ZnO films.

Zinc Oxide Nanostructures for Efficient Energy Conversion in Organic Solar Cell

We present a new approach of solution-processed using zinc oxide (ZnO) nanostructures as extraction layer material for organic solar cells. It is low chemical reaction compatibility with all types of organic blends and its good adhesion to both surfaces of ITO/glass substrate and the active layer (blends). Parameters such as the thickness and the morphology of the films were investigated to prove that these factors greatly affect the efficiency of organic solar cells. In this work, ZnO layer with thickness of approximately 53 nm was used as an interlayer to prevent pin-holes between the electrode and the polymer layer. The polymer layer was coated on the ZnO layer with the thickness of about 150 nm. The thick polymer layer will form a non-uniform surface because of the solvent, 1-2dichlorobenzene will etch away some region of the polymer layer and forming pin-holes. ZnO nanostructures layer was used to prevent pin-holes between the polymer layer and electrode. From the surface morphology of ZnO layer, it shows a uniform surface with particle grain size obtained between 50 -100 nm. The presence of the interlayer has a positive effect on the electrical characteristics of the solar cells. It was found that an organic solar cell with thickness less than 150 nm shows the optimum performance with efficiency of 0.0067% and Fill Factor (FF) of about 19.73.

Synthesis and Characterization of Zinc Oxide Nanostructures by Different Sonication Period

Zinc oxide (ZnO) is a wide band gap semiconductor material (3.37 eV) with numerous present applications such as varistors, surface acoustic wave devices and future biomedical applications. ZnO nanorods were grown under specific growth condition by an inexpensive and simple, chemical bath deposition method on ZnO seeded glass substrates. Study of the ZnO nanorods over different precursors, i.e zinc acetate dehydrate and zinc nitrate hexahydrate, and sonication period ranging from 0 to 120 seconds by field emission scanning electron microscope (FESEM), including the nanorod size and the surface morphology, will be demonstrated in this paper. Characterization of the ZnO film using both X-ray diffraction (XRD) and UV-Vis spectroscopy will be established in determining the optimal composition along with the optical properties, respectively.

Effects of Ageing Time of ZnO Sol on Properties of ZnO Films by Sol Gel Spin Coating

In recent years, there are many techniques developed to synthesize zinc oxide (ZnO) films. However, among the synthesis methods available, sol-gel has the most advantageous which offers cost effective features. In the present work, ZnO films were prepared by solgel spin coating technique. The effects of solution ageing times which varies at 2h 15 min, 3h 30 min and 24h were investigated. The structural, morphological and optical properties were studied using an x-ray diffractometer (XRD, Bruker D8 Advance), atomic force microscope (AFM, Tenko XE-100) and ultra violet-visible spectrophotometer (UV-Vis, Shimadzu UV 1800), respectively. Based on the XRD measurement, it was revealed that ZnO films were polycrystalline with hexagonal wurtzite structure. The crystallite size is in the range of 34.4 ~ 28 nm which decreased with ageing time increment. On the other hand, the AFM analysis revealed that the surface roughness of the films increased due to the increment of ageing times. Optical transmittance spectra indicate that all films were transparent (>75%) in the visible range which slightly improved with increasing of ageing times. The optical band gap was estimated to be around 3.24 ~3.26 eV using Taucs plot. We revealed that the ageing time of ZnO sol influenced the material properties of ZnO films. Based on our finding we proposed that 24h ageing time is optimum for the fabrication of high quality ZnO films.

Sol‐Gel Fabrications of ZnO Thin Films and Microstructures

Zinc oxide (ZnO) thin films, micro‐ and nanostructures are promising candidates for applications in optoelectronic devices. In this work, low cost sol‐gel spin coating and hydrothermal techniques were used to fabricate the ZnO films on glass substrates and ZnO microstructures on oxidized silicon substrates, respectively. The structural properties of the ZnO samples were examined using scanning electron microscope (SEM) and atomic force microscope (AFM). The influence of precursor concentration in the sol‐gel processes on the properties of the ZnO films and microstructures was investigated and will be discussed in this paper.

Microfabrication of ZnO structures using sol-gel immerse technique

Zinc oxide (ZnO) is an emerging material in large area electronic applications such as thin-film solar cells and transistors. We report on the fabrication and characterization of ZnO nanostructures. ZnO nanostructures have been synthesized using sol-gel immerse technique on oxidized silicon substrates. Different precursors concentrations ranging from 0.0001 M to 0.01 M (M=molarity) using zinc nitrate hexahydrate [Zn(NO3)2.6H2O] and hexamethylenetetramine [C6H12N4] were employed in the synthesis of the ZnO nanostructures. The surface morphologies were examined using scanning electron microscope (SEM) and the structural properties were measured using X-ray diffractometer (XRD). In order to investigate the optical properties, the ZnO nanostructures were measured using ultraviolet-visible (UV-Vis) spectroscopy. The electrical properties of the ZnO nanostructures were characterized using current-voltage (I-V) measurement system.

Direct current magnetron sputter-deposited ZnO thin films

Zinc oxide (ZnO) thin films were deposited on glass substrates at room temperature using direct current (DC) magnetron sputtering technique. The deposition pressure was varied from 12 mTorr to 25 mTorr. The influence of the deposition pressure on structural properties of the ZnO films was investigated using atomic force microscopy (AFM). The optical properties of the ZnO films were measured using Ocean Optics spectrometer. The experimental results reveal that the deposition pressure has an important role in the structural and optical properties of the ZnO films.

Effect of Immerse Duration on the Structural and Optical Properties of Zinc Oxide Nanorod

Zinc oxide (ZnO) is an emerging optoelectronic material in large area electronic applications that are due to its various functional behaviors. We present the fabrication and characterizations of ZnO nanorods. The ZnO nanorods were synthesized using sol-gel hydrothermal technique on oxidized silicon (Si) substrates. In the fabrication of ZnO nanorods, the oxidized Si substrates were immersed in ZnO aqueous solution for different durations ranging from 3 hours to 5 hours. The surface morphologies of the ZnO nanorods were examined using scanning electron microscope (SEM). In order to investigate the structural properties, the ZnO nanorods were measured using X-ray diffractometer (XRD). The optical properties were measured using ultraviolet-visible (UV-Vis) spectroscopy. The effect of the immerse duration on the material properties of the realized ZnO nanorods will be revealed and discussed in this paper.

Nucleation and growth of chrysanthemum-like zinc oxide crystals using silicon dioxide

Abstract The chrysanthemum-like ZnO crystal has been grown by dry oxidation process in the sol–gel method. The samples have been characterised using SEM and XRD. The surface morphology of SEM result shows that the structure is like a chrysanthemum flower. The chrysanthemum-like crystal has been synthesised and composed of one-dimensional nanorods which have hexagonal wurtzite structure. It is also shown that the nanorods were preferentially grown along the [001] direction. In this paper, the growth mechanism and synthesis technique of chrysanthemum-like nanostructured ZnO are explained in detail.