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Mohd Natashah Norizan
Preferred name
Mohd Natashah Norizan
Official Name
Mohd Natashah, Norizan
Alternative Name
Mohd, Natashah Norizan
Norizan, M. N.
Natashah Norizan, Mohd
Natashah, N. Mohd
Main Affiliation
Scopus Author ID
57226822517
Researcher ID
B-1263-2017
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1 - 10 of 44
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PublicationEffect of indium pre-flow on wavelength shift and crystal structure of deep green light emitting diodes( 2021-01-01)
;Hassan Z. ;Bakar A.S.A. ;Rahman M.N.A. ;Yusuf Y. ;Md Taib M.I. ;Sulaiman A.F. ;Hussin H.N. ;Nagai K. ;Akimoto Y.Shoji D.To produce a deep green (530 nm–570 nm) LED, the suitable indium (In) composition in the InxGa1−xN/GaN multi-quantum well (MQW) structure is crucial because a lower indium composition will shift the wavelength of emission towards the ultraviolet region. In this paper, we clarify the effects of an indium-rich layer to suppress such blue shifting, especially after the annealing process. According to characterizations by the uses of XRD and TEM, narrowing of the MQW layer was observed by the indium capping, while without the capping, the annealing results in a slight narrowing of MQW on the nearest layer to the p-type layer. By adding an indium capping layer, the blue shift of the photoluminescence was also suppressed and a slight red shift to keep green emission was observed. Such photoluminescence properties were consistent with the tiny change of the MQW as seen in the XRD and TEM characterizations. -
PublicationA Study on Electrical Performance of SiC-based Self-switching Diode (SSD) as a High Voltage High Power Device( 2023-12-01)
;Sha’ari N.Z.A.A. ;Ahmad M.F.The Self-switching Diodes (SSDs) have been primarily researched and used in low-power device applications for RF detection and harvesting applications. In this paper, we explore the potential of SSDs in high-voltage applications with the usage of Silicon Carbide (SiC) as substrate materials which offers improved efficiency and reduced energy consumption. Optimization in terms of the variation in the interface charges, metal work function, and doping concentration values has been performed by means of a 2D TCAD device simulator. The results showed that the SSD can block up to 600 V of voltage with an optimum interface charge value of 1013 cm-2, making them suitable for higher voltage applications. Furthermore, it also found that the work function of the metal contact affected the forward voltage value, impacting the current flow in the device. Variation in doping concentrations also resulted in higher breakdown voltages and significantly increased forward current, leading to an increased power rating of 27 kW. In conclusion, the usage of 4H-SiC-based SSDs shows a usable potential for high-voltage applications with optimized parameters. The results from this research can facilitate the implementation of SSD in the development of high-power semiconductor devices for various industrial applications. -
PublicationSynthesis Methods of Tin Oxide as Photoanode for Dye-Sensitized Solar Cell Performance: A Short Review( 2021-12-01)
;Idris S.N. ;Magiswaran K.Sobri S.A.This review focused on the synthesis methods of tin oxide (SnO2) nanoparticles as a photoanode for dye-sensitized solar cell (DSSC) and how it impacts the performance. There are many different techniques and various nanoparticles were produced and usually characterized by X-ray diffraction (XRD) to determine crystalline structure of SnO2, scanning electron microscopy (SEM) to examine the surface morphology and size details and J-V solar simulator to verify current-voltage characteristics. In summary, considering all the methods reviewed, sol-gel is reported as the best method to produce SnO2 nanoparticles for DSSC fabrication with the highest efficiency recorded of 3.96%. -
PublicationAugmentation of the delamination factor in drilling of carbon fibre-reinforced polymer composites (CFRP)( 2020-11-01)
;Sobri, Sharizal Ahmad ;Whitehead D. ;Mohamed M. ;Mohamed J.J. ;Amini M.H.M. ;Hermawan A. ;Rasat M.S.M. ;Sofi A.Z.M. ;Ismail W.O.A.S.W.Carbon fibre-reinforced polymer (CFRP) composite materials play an increasingly important role in modern manufacturing, and they are among the more prominent materials used in aircraft manufacturing today. However, CFRP is highly prone to delamination and other damage when drilled due to it being extremely strong with a good strength-to-weight ratio and high thermal conductivity. Because of this problem and CFRP’s growing importance in aircraft manufacture, research has focused on the entry and exit holes as indicators of damage occurrence during drilling of screws, rivets, and other types of holes. The inside of the hole was neglected in past research and a proper way to quantify the internal side of a hole by combining the entry and exit hole should be included. To fill this gap and improve the use of CFRP, this paper reports a novel technique to measure the holes by using the extension of the adjusted delamination factor (SFDSR) for drilling thick CFRP composites in order to establish the influence of machining input variables on key output measures, i.e., delamination and other damages. The experimental results showed a significant difference in interpretation of the damage during the analysis. Improvement was made by providing better perspectives of identifying hole defects. -
PublicationRecent advances in synthesis of Graphite from agricultural bio-waste material : a review( 2023-05-08)
;Yee Wen Yap ;Kamrosni Abdul RazakMohd Yusry Mohamad YunusGraphitic carbon is a valuable material that can be utilized in many fields, such as electronics, energy storage and wastewater filtration. Due to the high demand for commercial graphite, an alternative raw material with lower costs that is environmentally friendly has been explored. Amongst these, an agricultural bio-waste material has become an option due to its highly bioactive properties, such as bioavailability, antioxidant, antimicrobial, in vitro and anti-inflammatory properties. In addition, biomass wastes usually have high organic carbon content, which has been discovered by many researchers as an alternative carbon material to produce graphite. However, there are several challenges associated with the graphite production process from biomass waste materials, such as impurities, the processing conditions and production costs. Agricultural bio-waste materials typically contain many volatiles and impurities, which can interfere with the synthesis process and reduce the quality of the graphitic carbon produced. Moreover, the processing conditions required for the synthesis of graphitic carbon from agricultural biomass waste materials are quite challenging to optimize. The temperature, pressure, catalyst used and other parameters must be carefully controlled to ensure that the desired product is obtained. Nevertheless, the use of agricultural biomass waste materials as a raw material for graphitic carbon synthesis can reduce the production costs. Improving the overall cost-effectiveness of this approach depends on many factors, including the availability and cost of the feedstock, the processing costs and the market demand for the final product. Therefore, in this review, the importance of biomass waste utilization is discussed. Various methods of synthesizing graphitic carbon are also reviewed. The discussion ranges from the conversion of biomass waste into carbon-rich feedstocks with different recent advances to the method of synthesis of graphitic carbon. The importance of utilizing agricultural biomass waste and the types of potential biomass waste carbon precursors and their pre-treatment methods are also reviewed. Finally, the gaps found in the previous research are proposed as a future research suggestion. Overall, the synthesis of graphite from agricultural bio-waste materials is a promising area of research, but more work is needed to address the challenges associated with this process and to demonstrate its viability at scale. -
PublicationCharge recombination in zinc oxide-based dye-sensitized solar cell: a mini review( 2021-12)
;Kaiswariah Magiswaran ;Siti Norhafizah IdrisSharizal Ahmad SobriDye-sensitized solar cell (DSSC) has been studied widely due to its efficiency and the simplicity of manufacturing technology. Much research has been performed to improve the photovoltaic output parameters in DSSC by modifying the photoanode layers. The efforts to investigate DSSC mainly focus on how to increase light absorption, speed electron transport in circuits, and reduce charge recombination. This review discusses the process of charge recombination and the paths of occurrence in a DSSC. Recombination occurs when the electrons in the conduction band fall into the valance band holes and is considered an unnecessary process in DSSC. Due to the recombination process, the photocurrent and the photovoltage are reduced, leading to lower power conversion efficiency. Hence, the ways to overcome the charge recombination process were also discussed. -
PublicationA simple sensor network designed as anti-theft alarm system for copper cables( 2021-05-03)
;Zainol M.Z. ;Ahmad M.F.At present, the copper resources supply is very demanding, with society develops quickly. The increment of copper cable theft is due to the interest of its characteristic of low transmission voltage, dispersed layout, and high Cu in the material composition. The public utilities such as telecommunication providers faced plenty of troubles and dangers as they are the primary target. As a result of cable theft, the consumers cannot use the telephony system or internet services at their premises. These affect the communication between families, clients, and business purposes, including for emergency cases. Therefore, to prevent cable theft widespread, this work creates a device that is capable of alarming the responsible party when the copper at a specified location has been cut-off or tempered by thieves. A prototype has been developed for this work. Upon detection of a cable cut occurrence, this system will automatically activate the alarm and provide a display to indicate the specific location of where the cable was cut off. The system is controlled by an MCU unit (PIC16F877A). This work is using cable feeders in which the arrangement of the resistor in parallel determines the distance of the cable is terminated with the aid of the voltage divider concept. -
PublicationAnalysis of Symmetric Two and Four-coil Magnetic Resonant Coupling Wireless Power Transfer( 2022-04-01)
;Ali A. ;Rambe A.H. ;Ramli N.Sobri S.A.This study examined the efficiency of power transfer for two-coil and four-coil spiral magnetic resonant coupling wireless power transfer (WPT) using distance to coil diameter (D/dm) ratio and reflection coefficient, S21 value. Adding resonators reduced the total resistance in the two-coil WPT system while increasing the S21 values of the whole system. A same-size spiral coil was proposed for the system and simulated using computer simulation technology (CST). A prototype with similar specifications for a four-coil design was implemented for verification. The proposed method yielded an optimal efficiency of 76.3% in the four-coil system, while the two-coil WPT yielded a 23.2% efficiency with a 1.33 D/dm ratio. -
PublicationModification of photoanode surface structure via image analysis on organic polymer material based for dye-sensitized solar cell (DSSC) applications( 2021-12)
;N. Rosli ;MF Ahmad ;NF ZakariaIn this study, the experiment on the modification of the photoanode with organic polymer material as copolymer template for dye-sensitized solar cell (DSSC) applications has been conducted. The two organic copolymer templates are polystyrene sphere (PS) and poly[2- methoxy-5(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV). The modification photoanodes were made using Dr. Blade’s method. These organic copolymer templates were added to improve the surface of the mesoporous titanium dioxide (TiO₂) layer, which is used as the main component in DSSC photoanode. The unmodified TiO₂ photoanode has poor aggregation and porosity of TiO₂. The addition of either MEH-PPV or PS sphere to the photoanode layer was found to affect the surface of mesoporous TiO₂ in terms of porosity, particle size distribution and shape. The analysis of the TiO2 modification was conducted using an image analysis processing method via a 2D scanning electron microscope (SEM) image. The image analysis processing method used was the ImageJ program. The DSSC of modified photoanode is fabricated using metal complex dye, Ruthenium (N719) dye. The data collected from the ImageJ program showed that by adding organic copolymer templates into TiO₂, the porosity of TiO₂ decreased from 45 % to 42 %. From the photovoltaic analysis obtained, the J-V characteristic is recorded with the photoanode of TiO₂ mixed with 1.00 wt% MEH-PPV gave the highest efficiency, which is 0.01 % with the following parameters – Voc = 0.43 V, Jsc = 0.17 mA/cm2 and FF = 0.20. Meanwhile, the photoanode of TiO₂ mixed with 0.50 wt% PS sphere gave the highest efficiency which is 0.08 % with the following parameters – Voc = 0.39 V, Jsc = 0.86 mA/cm2 and FF = 0.25. -
PublicationIndium (In) Effects to The Efficiency Performance of Ga1-XInxP/GaAs Based Solar Cell Using Silvaco Software Modelling & Simulation( 2017-06-27)
;Suhaila Mohd Zahari ;Shahimin M.M.Ga1-xInxP composition has been applied to the top cell of multi-junction GaInP/GaAs based solar cell and currently have achieving a conversion efficiency of more than 46%, however its capability is unclear. We performed an analysis using Silvaco simulation method to evaluate the effect of In and the substitution was made to the Ga1-xInxP for the range of x from 0 to 1. We found that the highest efficiency recorded was 17.66% when the composition of Indium was x=1. The efficiency has been increasing about 11.71% from x=0 to x=1 In content. As the composition of In raised, the value of efficiency and short circuit current density, Jsc also become higher (13.60 mA/cm2) by having a greater photon absorption in a wider band gap energy. In addition to that, Voc, Pmax, Vmax, Imax and fill factor was measured to be 2.15 V, 2.44 mW/cm2, 2.0 V, 1.22 mA/cm2 and 83.34 respectively. In conclusion, this study confirms that the existence of In in Ga1-xInxP improves the solar cell efficiency by gaining a higher energy gap and producing more electrons for best achievement in multilayer solar cell applications.