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Shah Alam, Malaysia

Radzi A.A.S.M.,University Technology of MARA | Yarmo M.A.,National University of Malaysia | Rusop M.,University Technology of MARA | Rusop M.,ElecTronic Center | Abdullah S.,University Technology of MARA
Advanced Materials Research | Year: 2013

Multilayer structure of porous silicon was fabricated using electrochemical etching method. Average thickness of multilayer structure was verified. Surface morphology from Atomic Force Microscopy (AFM) shows that surface roughness was decreased when higher etching time applied to the samples. Si 2p binding energies were corresponded to the composition of void within the silicon which prompted the formation of porous silicon nanostructure. Depth profiling technique from X-Ray photoelectron spectroscopy (XPS) was used for compositional determination of porous silicon layers since samples' porosity varied according to current density applied during the electrochemical etching process. Multilayer porous silicon is a high potential candidate for Bragg grating waveguide device. © (2013) Trans Tech Publications, Switzerland. Source

Fadzilah A.N.,ElecTronic Center | Rusop M.,University Technology of MARA
International Conference on Electronic Devices, Systems, and Applications | Year: 2011

The work presented here shows the effect of deposition temperature on amorphous carbon (a-C) thin films. The a-C thin film were deposited on glass substrate by pyrolysing camphor oil at various temperature using the Chemical Vapor Deposition (CVD) technique. The films were prepared at various deposition temperature ranging from 350°C to 500°C. The electrical, optical and structural properties were characterized by current-voltage (I-V) Measurement, UV-VIS-NIR Spectrophotometer and Atomic Force Microscopy (AFM) respectively. As the deposition temperature increase, the conductivity increased but the optical band gap decrease from 1.5eV to 0.5eV due to the formation of more sp 2 bonded carbon configuration. © 2011 IEEE. Source

Rahim N.A.A.,Microwave Technology Center | Kara M.H.,ElecTronic Center | Mahmood M.R.,University Technology of MARA
2014 IEEE Asia-Pacific Conference on Applied Electromagnetics, APACE 2014 - Proceeding | Year: 2015

The experimental results for high-frequency characteristics (from 2 to 20 GHz) of graphene films are presented. Samples with multi-layer graphene were fabricated and characterized from curve-fitting experimental results with values simulated using an electromagnetic simulator. From RF two-port network experiments, the circuit parameters of capacitance, resistance and inductance were extracted using a physics-based RLC lumped element circuit model that consists of contact pads and graphene electrodes using a commercially available microwave circuit simulator. The proposed model reproduced all the measured characteristics, and the component values which gave the best fit with the measurements were successfully extracted from the model. Our findings demonstrate that the measured RF performance of multilayer graphene (MLG)-based transmission lines gave good agreement with simulation predicted by a lumped element RLC model. © 2014 IEEE. Source

Md Sin N.D.,ElecTronic Center | Mamat M.H.,ElecTronic Center | Rodzi A.S.,University of Zagreb | Rodzi A.S.,University Technology of MARA | Rusop M.,ElecTronic Center
AIP Conference Proceedings | Year: 2011

The electrically conductive zinc oxide (ZnO) nanostructures prepared by sol-gel spin coating are presented. This project has been focused on electrical, optical and surface morphology properties of Al (aluminium) doped ZnO thin film. The effect of Al doping concentration at 0∼5 at.% on the Al doped ZnO Thin film properties have been investigated. This project involves 3 processes which are thin film preparation, deposition and characterization. The thin films were characterized using Current-Voltage (I-V) measurement and UV-Vis-NIR spectrophotometer for electrical properties and optical properties respectively. The surface morphology has been characterized using field emission scanning electron microscope (FESEM). The I-V measurement result indicated electrical properties of Al doped ZnO thin film improved with Al doping. The absorption coefficient spectra obtained from UV-Vis-NIR spectrophotometer measurement show all films have low absorbance in visible and near infrared (IR) region but have high UV absorption properties. The FESEM investigations show that the nanoparticles size becomes smaller and denser as the doping increase. © 2011 American Institute of Physics. Source

Suriani A.B.,Sultan Idris University of Education | Alfarisa S.,Sultan Idris University of Education | Mohamed A.,Sultan Idris University of Education | Isa I.M.,Sultan Idris University of Education | And 4 more authors.
Materials Letters | Year: 2015

Quasi-aligned carbon nanotubes (CNTs) were successfully synthesised for the first time using waste engine oil (WEO) as the carbon source via thermal chemical vapour deposition (TCVD). The high carbon content of WEO was believed to promote the growth of the quasi-aligned CNTs. The synthesis process was performed at precursor and synthesis temperatures of 500 and 750 °C, respectively, with a ferrocene catalyst concentration of 17.99 wt%. Typical characterisation methods were employed to examine the CNTs: electron microscopy, energy dispersive X-Ray, X-ray diffraction and micro-Raman spectroscopy. The ability of CNT samples to emit electrons was also investigated by field electron emission (FEE) analysis. Electron microscopy and micro-Raman analysis revealed a dense mixture of quasi-aligned single- and multi-walled CNTs with a moderate ID/IG ratio of 0.90. The overall diameters of the CNTs ranged from 18.0 to 29.8 nm, with the diameters of the single-walled CNTs estimated to be between 0.6 and 1.1 nm. The FEE results showed that the quasi-aligned CNTs synthesised from WEO exhibited reasonable turn-on and threshold fields of 4.1 and 7.2 V μm-1, which corresponded to current densities of 0.1 and 1.0 μA cm-2, respectively. This study highlights WEO as a new, cheap, abundant and easily available carbon source for quasi-aligned CNTs production with a potential application in electron emission devices. © 2014 Elsevier B.V. Source

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