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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 48
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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. -
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. -
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 Zakaria ;In 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. -
PublicationLife cycle assessment (Lca) of particleboard: Investigation of the environmental parameters( 2021-07-01)
;Mohd Azman M.A.H. ;Ahmad Sobri S. ; ;Ahmad M.N. ;Wan Ismail W.O.A.S. ;Hambali K.A. ;Hairi M.H. ;Hermawan A. ;Mohamed M. ;Teo P.T. ;Taharin M.R.Noor N.A.M.Particleboard is not entirely a wood replacement but a particular material with its properties, making it more effective at different times than heavy or solid wood. The world’s biggest concern is environmental problems with formaldehyde as a particulate board binder that can lead to human carcinogenic agents. A cradle-to-gate life cycle assessment (LCA) of particleboard production was performed using openLCA software. The impact assessment was carried out according to the software’s features. This preliminary investigation aims to analyze the chemical composition of particleboard and identify its environmental impact. The Fourier-transform infrared spectroscopy (FTIR) system was used to track the functional group of aliphatic hydrocarbons, inorganic phosphates, and main aliphatic alcohols found in particleboards made in Malaysia. Based on the FTIR results, aliphatic groups were found in numerous aggravates that the spectroscopic infrared was likely to experience. The most important vibrational modes were C–H, at approximately 3000 cm−1, and –CH deformations around 1460 cm−1 and 1380 cm−1 . Eight effect groups demonstrated that 100% of the input and all analyses produced the same relative outcome. The life cycle of a product is determined by pollution of the air, water, and soil. Thus, particleboard has a minimal impact on the environment, except for global warming. -
PublicationFailure mode and effects analysis (FMEA) of furniture production: A case study in Kelantan state, Malaysia( 2021-05-03)
;Ahmad M.F. ;Sobri S.A. ;Abdullah N.A.N. ;Kamarudin N.M.F.N. ;Mohamed M. ;Hermawan A. ;Boon J.G. ;Ismail W.O.A.S.W.The primary objective of this research is to study the critical region of the local furniture manufacturing company by using a Failure Mode and Effects Analysis (FMEA). At the same time, the study also aims to help the organization to minimize production costs by presenting the preliminary stage of the results of the assessment. Many industries used FMEA as a method to improve the evaluation of the reliability of a production process. The use of FMEA is to analyze the layout characteristics of the planned production process in order to ensure that the final product meets customer requirements and expectations. It uses probabilities of detection and occurrence added with a few severity standards to create a risk priority number (RPN) for rating improvement action considerations. Utilized in both the manufacturing and design processes, they notably help to reduce cost factors with the aid of determining product and process improvements early within the development process while changes are inexpensively and relatedly easy to do. Based on the results, there were two failure modes with a higher RPN. The assessment is deductive as it periodically moves from one source to another. Thus, it can assist the company in improving its manufacturing process by reducing the mistakes that been made by identifying the cause and effect of it. -
PublicationThe influence of laser cutting parameters on the heat-affected zone in fast-growing Malaysian wood species(Multidisciplinary Digital Publishing Institute (MDPI), 2025-02)
;Mohd Sharizal Sobri ;Sharizal Ahmad Sobri ; ;Andi Hermawan ;Mohd Hazim Mohamad Amini ;Mazlan Mohamed ;Wan Omar Ali Saifuddin Wan IsmailAl Amin Mohamed SultanWood is a naturally occurring renewable resource widely used in various industries, including in construction, packaging, furniture, and paneling. In Malaysia, 80% of furniture products are made from wood, making it a crucial material in this sector. Laser cutting is an advanced machining technique that enhances precision and minimizes material waste, yet its thermal effects, particularly the heat-affected zone (HAZ), remain a challenge. This study investigates how laser cutting parameters—including the laser power, traverse speed, and focus position—affect HAZ formation in two fast-growing Malaysian wood species, Acacia mangium and Azadirachta excelsa. This research seeks to determine the optimal laser settings that minimize HAZ dimensions while maintaining cutting precision. A diode laser cutting system was used to analyze the effects of three laser power levels (800, 1500, and 2400 mW), three traverse speeds (2, 5, and 10 mm/s), and three focus positions (on-focus, +0.2 mm, and −0.2 mm). We employed statistical analysis, including a two-way ANOVA, to assess the significance of these parameters and their interactions (p < 0.001). The results indicate that a higher laser power and slower speeds significantly increase the HAZ’s width and depth, with Azadirachta excelsa exhibiting a greater HAZ width but shallower penetration compared to Acacia mangium. A slight above-focus position (+0.2 mm) reduces the HAZ’s width, whereas a below-focus position (−0.2 mm) increases the HAZ’s depth. The optimal parameters for minimizing HAZ dimensions while ensuring efficient cutting were identified as a 1500 mW laser power, a 10 mm/s traverse speed, and an on-focus position (0 mm). This study provides practical insights into laser parameter optimization for tropical wood species, contributing to improved precision in laser machining and sustainable wood processing practices. These findings support industries in adopting advanced, high-quality laser cutting techniques tailored to fast-growing wood resources. -
PublicationTemperature-dependent properties of Cu-doped ZnTe thin films deposited on ultra-thin glass substrates via RF magnetron sputtering(Elsevier B.V., 2025-01)
; ;Ahmad Wafi Mahmood Zuhdi ;Camellia Doroody ;Yap Boon Kar ;Mohd Nazri Abd Rahman ;Kazi Sajedur Rahman ; ;Muhammad Najib HarifTiong Sieh KiongThis study investigates the viability of Cu-doped ZnTe as a potential back surface field (BSF) layer on flexible CdTe thin-film solar cells, examining its structural, morphological, optical, and electrical properties. ZnTe, 5%, and 8% Cu-doped ZnTe were deposited on ultra-thin glass (UTG) substrates using the radio frequency (RF) magnetron sputtering approach at varying substrate temperatures from room temperature to 300 °C. The finding reveals that the surface morphology significantly changes as the substrate temperature increases. Besides, incorporating Cu into ZnTe resulted in a denser and rougher surface, likely due to material densification and accelerated grain growth at higher temperatures. X-ray diffraction (XRD) analysis indicated that the crystallite size of the ZnTe and Cu-doped ZnTe increased with higher temperatures. Optical spectroscopy results demonstrated an increase in the optical band gap of ZnTe with increasing substrate temperature, while Cu-doping introduced a significant variability in the bandgap, particularly at different doping levels. In terms of electrical properties, ZnTe thin films exhibited carrier concentrations around 1014 cm−3. Conversely, the introduction of 5% and 8% Cu into ZnTe increased carrier concentrations, ranging from 1017 to 1020 cm−3, respectively, depending on substrate temperature and the amount of Cu concentration. Introducing Cu in the ZnTe structure may modify the characteristics of ZnTe thin films, potentially influencing its suitability as a BSF layer in CdTe solar cells by affecting its structural, optical, and electrical properties. -
PublicationAdsorption efficiency and photocatalytic activity of silver sulphide-activated carbon (Ag₂S-AC) composites(Elsevier B.V., 2025)
;Siti Norsaffirah Zailan ; ;Aissa Bouaissi ;Zahra Ramadlan Mubarokah ; ;Nurfina Yudasari ;Siti Salwa Mohammad ShirajuddinBackground: This study investigates the adsorption efficiency and photocatalytic activity of silver sulphide-activated carbon (Ag₂S-AC) composites derived from ground coffee waste (GCW). Methods: In this work, GCW was preceding to carbonized at 500 ± 2°C for hours and formed biochar. Then, GCW was subjected to activation using hydrochloric acid (HCl), phosphoric acid (H₃PO₄) and potassium hydroxide (KOH). The mixture was left to soak for 24 h at room temperature, followed by carbonization at 350 and 500˚C. In the meantime, the silver sulphide (Ag₂S) was synthesized by using an ion exchange method. Sodium sulphide (Na₂S) was used as sulphur source and mixed with silver nitrate (AgNO₃) and sodium citrate (NaCit) for two hours, then dried in oven at 50 ± 2°C for 10 h. Next, the carbonized AC was subsequently combined with synthesized silver sulphide, resulting in the creation of Ag₂S-activated carbon composites that functioned both as adsorbent and photocatalyst. Their capabilities as adsorbents and photocatalyst were studied by using copper ions (Cu2+) and methylene blue (MB) solution. Significance findings: Based on results, GCW and all the prepared activated carbons are in the amorphous phase, except for the Ag₂S-AC composites, where the Ag₂S peak reflection can be observed from the X-ray diffraction (XRD) pattern. GCW shows rough and dense surface morphology. The AC shows different pore sizes and structures depending on the chemical activators used, where AC-KOH shows the largest pore size (165.31 μm). The existence of micropores can be observed in all the activated carbon samples. For the adsorption of Cu2+, all samples show more than 99 % of the removal efficiency. While for photocatalytic testing, the Ag₂S-H₃PO₄ sample shows the highest degradation rate (97.7 %) of MB solutions. -
PublicationElectrical Performance of Curcuma longa Extract Dye using SnO2-Based Photoanode Dye-Sensitized Solar Cell( 2022-12-01)
;Siti Norhafizah Idris ; ; ; ;Magiswaran K.Abas Z.A.Due to their low output costs, straightforward manufacturing, and high effectiveness, dye-sensitized solar cell (DSSC) has a large following interest in the solar energy industry. Furthermore, due to its outstanding properties, tin oxide (SnO2) is an appealing semiconducting material suitable as a photoanode in DSSCs. In this research, the photoelectrodes of DSSC were fabricated using commercial SnO2 nanoparticles and sensitized with inorganic and organic dyes, N719 and Curcuma longa (turmeric) extract dye. On top of that, a platinum (Pt) counter electrode, iodide electrolyte and fluorine-doped tin oxide (FTO) coated glass substrate were used to fabricate the DSSC. The crystallographic structure and surface morphology of the SnO2 nanopowder were identified using X-ray diffraction (XRD) and scanning electron microscopy (SEM) characterizations respectively. In addition, UV-Visible and current density-voltage curves were used to analyze the optical properties of the photoanodes and the cell’s electrical performance. As a result, it was found that the DSSC fabricated with N719 dye exhibited higher efficiency in contrast with the turmeric extract dye with SnO2 photoanodes.1 -
PublicationEnhancement of Power Conversion Efficiency with Zinc Oxide as Photoanode and Cyanococcus, Punica granatum L., and Vitis vinifera as Natural Fruit Dyes for Dye-Sensitized Solar Cells( 2022-11-01)
; ; ; ;Jamalullail N. ; ; ;Sandu A.V. ;Baltatu M.S.Vizureanu P.Ruthenium N719 is a well-known material used as the dye in commercial dye-sensitized solar cell (DSSC) devices. However, it poses risks to human health and the environment over time. On the other hand, titanium dioxide (TiO2) has low electron mobility and high recombination losses when used as a photoanode in this photovoltaic technology device. In addition, using Ruthenium as the dye material harms the environment and human health. As an alternative sensitizer to compensate Ruthenium on two different photoanodes (TiO2 and ZnO), we constructed DSSC devices in this study using three different natural dyes (blueberry, pomegranate, and black grape). In good agreement with the anthocyanin content in the fruits, black grape, with the highest anthocyanin content (450.3 mg/L) compared to other fruit dyes (blueberry—386.6 mg/L and pomegranate—450.3 mg/L), resulted in the highest energy conversion efficiency (3.63%) for the natural dye-based DSSC. Furthermore, this research proved that the electrical performance of natural dye sensitizer in DSSC applications with a ZnO photoanode is better than using hazardous Ru N719 dye with a TiO2 photoanode owing to the advantage of high electron mobility in ZnO.1 31