Muhammad Azmi Abd Hamid

Characterization of Cuprous Oxide Thin Films Prepared by Sol-Gel Spin Coating Technique with Different Additives

Cuprous oxide (Cu2O) thin films were formed onto indium tin oxide (ITO) coated glass substrate by sol-gel spin coating technique using different additives namely polyethylene glycol and ethylene glycol. It was found that the organic additives added had an important influenced on the formation mechanism of Cu2O films and lead to different microstructures and optical properties. The films were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and ultraviolet-visible spectroscopy (UV-Vis). Based on the FESEM micrographs the grain size of film prepared by polyethylene glycol has smallest grain of about 83 nm with irregular shape. The highest optical absorbance film was obtained by the addition of polyethylene glycol.

Growth Behaviour of ZnO on Si (100) and Platinum Coated Glass Substrate from Aqueous Solution

Zinc oxide nanorods were grown on Si (100) and Platinum coated glass substrate by the aqueous chemical growth (ACG) in aqueous solution that contained zinc nitrate hexahydrate (Zn(NO3)2•6H20) and hexamethylenetetramine (C6H12N4). The obtained ZnO nanorods are uniformly distributed on the Platinum coated glass substrate surface from 1.5 h to 3 h growth time. Branched hexagonal rods were also found growth on these uniform nanorods. Branched hexagonal rods were found on Si (100) from 2 h to 3 h growth time. A small number of flower-like structures compared to the majority oval type structure suggest that secondary nucleation had occurred during the process of growth. All of the high intensity peaks, including the strong (101) peak, are assigned to wurtzite ZnO hexagonal indicating that the product is pure ZnO. The results found in this study revealed that the type substrate plays a role in determining the surface morphology of ZnO growth.

Cuprous Oxide Thin Films for a Photoelectrochemical Cell of ITO/Cu2O/PVC-LiClO4/Graphite

Cuprous oxide (Cu2O) thin films were formed onto indium tin oxide (ITO) coated glass substrate by sol-gel spin coating technique using different additives namely polyethylene glycol and ethylene glycol. It was found that the organic additives added had an important influenced on the formation mechanism of Cu2O films and lead to different microstructures and optical properties. The films were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and ultraviolet-visible spectroscopy (UV-Vis). Based on the FESEM micrographs the grain size of film prepared by polyethylene glycol has smaller grain of about 83 nm with irregular shape. The highest optical absorbance film was obtained by the addition of polyethylene glycol which improved optical properties due to fine crystalline grain and thus decreases the scattering. The prepared cuprous oxide thin films were used as working electrodes for photovoltaic cell of ITO/Cu2O/PVC-LiClO4/graphite and tested using current-voltage characteristic under light illumination and also in the dark.

Effects of Annealing on the Properties of Copper Oxide Thin Films

Thin films of copper oxide were successively deposited on glass substrates by sol-gel like spin coating for 40 s and annealed in air at different temperatures (200-400°C). Precursor solutions were prepared by dissolving cupric chloride in methanol. Various stabilizers and additives were used to enhance the solubility of cupric chloride and to improve the adhesion between the films and the glass substrates. Glucopone was used as a surfactant to reduce the surface energy. The evolution of oxide coatings under thermal treatment was studied by glancing incidence X-ray diffraction and scanning electron microscopy. Annealing the films in air at 300°C converts the films to CuO. The general appearances of the films were uniform and brownish in color.

Synthesis and Characterization of Visible-Active Molybdenum Disulfide (2H-MoS2) Nanospheres

In current study, a novel 2H-MoS2 nanospheres were successfully synthesized and underwent structural- as well as optical-property characterizations. The MoS2 were prepared by one pot hydrothermal approach through adopting L-cysteine as environmentally-benignchalcogenide precursor. TEM image shows that the as-synthesized MoS2 appear to be spherical in shape with size distribution in the range of 120 nm – 180 nm. HRTEM lattice-fringes imaging further elucidate that the interlayer spacing at the edges is equal to be 0.62 nm that correspond to (002) plane stacking. Also, the HRTEM image clearly-illustrate that the internal microstructure of MoS2 composed of randomly-arrayed alternating layers, which render the postulation that the formation of nanosphere is driven by self-assembly of individual layers into globular morphology. XRD diffractogram that appear to be broad and unresolved reveal the partially crystalline nature of the sample. Optical-absorption spectra depicts the sample is visible active with feat...

Ohmic Contact in P-HEMT Wafer Using Metallization with Ge/Au/Ni/Au

In this study, Ohmic contact were fabricated on AlGaAs HEMTs structure. A good metal-semiconductor interface are essentially for achieving lower specific contact resistance. An AlGaAs epi wafer was supply by the vendor. AlGaAs substrate was cleaned using wet chemical etching. Electrodes were fabricated through a sequenced of lithography, cleaning, sputtering and lift-off processes. The electrodes were made with metal layers of Ge, Au and Ni. Parameters such as metal thickness, annealing temperatures (from 300°C to 400°C) and annealing time were varies during fabrication process. Electrical characterizations after annealing are carried out using transmission line method (TLM) to obtain the specific contact resistance. Annealing temperature between 340°C to 360°C produced contact resistance below 5 x 10ˉ³Ω/cm-2.

Preparation of Photoelectrochemical Cell of ITO/Cu2O/PVC-LiClO4/Graphite Using Cu2O Films as an Active Layer

Cuprous oxide (Cu2O) thin films were successfully grown on indium tin oxide (ITO) coated glass by sol-gel spin coating using diethanolamine (DEA) as a solubility agent. The films were annealed at 350 °C in 5% H2 + 95% N2 atmosphere. The films were characterized by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). Based on the SEM micrograph of the as obtained film, the film shows better coverage with the four sided pyramidal shape grain size of 108 nm. The prepared Cu2O thin film was used as an active electrode for photoelectrochemical cell of ITO/Cu2O/PVC-LiClO4/graphite. The photovoltaic cell was tested using current-voltage characteristic under light illumination of 100 mW/cm2.

Mechanism of Current Transport for a Photoelectrochemical Cells of ITO/Cu2O/PVC–LiClO4/Graphite

This paper deals with the current transport mechanism of solid state photoelectrochemical cells of ITO/Cu2O/PVCLiClO4/graphite as well as the physical properties of a component of a device affecting its performance. The principle of operation used in the photoelectrochemical cells is presented. The device makes use of ITO films, Cu2O films, PVCLiClO4 and graphite films as photoanode, photovoltaic material, solid electrolyte and counter electrode, respectively. The device shows rectification. The Jsc and Voc obtained at 100 mW cm2 were 3.2 x 10-11 mA/cm2 and 0.92 V, respectively.

Microstructures Study on Cuprous Oxide Thin Films Deposited on Different Substrates by Using Sol-Gel Technique

Cuprous oxide (Cu2O) thin films were formed onto three different substrates such as indium tin oxide (ITO) coated glass, titanium oxide (TiO2) and n-Si substrates by sol-gel spin coating technique. It was found that the formation mechanism of Cu2O films onto different substrates lead to different microstructures. The films were characterized by field-emission scanning electron microscopy (FESEM). Based on the FESEM micrographs the grain shape of film prepared were different on ITO, TiO2 and n-Si substrate with 114 nm, 154 nm and 84 nm respectively. The results indicate that the choice of substrate strongly affect the film morphology, structural and optical properties. Keywords: Cu2O, thin films, ITO, sol-gel, microstructures

Effect of Ca Content on Mechanical Properties of 4N Gold Wire for Quad Flat Nolead (QFN) Stacked Die Package

This paper discusses the effect of two similar gold wire (wire A and wire B) used mainly as a wire bonding material for Quad Flat Nolead (QFN) package. Both wires with diameter of 25.4 μm were bonded using automatic wire bonder by maintaining the temperature at 200°C. The effect of trace elements on the mechanical properties of 4N gold wire has not been widely investigated for some years despite the important of wire-bonding and the move towards fine pitch applications. Due to the element analysis, atomic percentage of Ca in wire B is higher than wire A. Pull strength increase with the increasing of the trace element. The higher pull strength of wire B could improve the yield strength, elastic modulus and recrytallization temperature.