Mohd Natashah Norizan
Thumbnail Image
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

Research Output

Filters

8 1
8
Reset filters

Settings
Now showing 1 - 8 of 8
  • Publication
    Effect of indium pre-flow on wavelength shift and crystal structure of deep green light emitting diodes
    ( 2021-01-01)
    Shamsul Amir Abdul Rais
    ;
    Hassan Z.
    ;
    Bakar A.S.A.
    ;
    Rahman M.N.A.
    ;
    Yusuf Y.
    ;
    Md Taib M.I.
    ;
    Sulaiman A.F.
    ;
    Hussin H.N.
    ;
    Mohd Fairus Ahmad
    ;
    Mohd Natashah Norizan
    ;
    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.
  • Publication
    A 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.
    ;
    Nor Farhani Zakaria
    ;
    Shahrir Rizal Kasjoo
    ;
    Ahmad M.F.
    ;
    Mohd Natashah Norizan
    ;
    Ili Salwani Mohamad
    ;
    Mohd Fairus Ahmad
    ;
    Shamsul Amir Abdul Rais
    ;
    Banu Poobalan
    ;
    Norhayati Sabani
    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.
  • Publication
    A study on electrical performance of SiC-based self-switching diode (SSD) as a high voltage high power device
    ( 2023-12)
    N. Z. A. A. Sha’ari
    ;
    Nor Farhani Zakaria
    ;
    Shahrir Rizal Kasjoo
    ;
    Mohd Natashah Norizan
    ;
    Ili Salwani Mohamad
    ;
    Mohd Fairus Ahmad
    ;
    Shamsul Amir Abdul Rais
    ;
    Banu Poobalan
    ;
    Norhayati Sabani
    ;
    A. F. A. Rahim
    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.
  • Publication
    Copper doping effect in the back surface field layer of CdTe thin film solar cells
    ( 2024-02-01)
    Nur Irwany Ahmad
    ;
    Kiong T.S.
    ;
    Doroody C.
    ;
    Rahman K.S.
    ;
    Mohd Natashah Norizan
    ;
    Mohd Fairus Ahmad
    ;
    Kar Y.B.
    ;
    Harif M.N.
    ;
    Amin N.
    In this work, the Solar Cell Capacitance Simulator (SCAPS-1D) is employed to evaluate the characteristics of CdTe thin films with ZnTe as the Back Surface Field (BSF) layer and estimate the effective copper doping ratio at both the atomic scale and the device operational response perspective. The electrical characteristics of ZnTe, at varying levels of copper doping, were derived using density functional theory (DFT) by applying the generalized gradient approximation (GGA) and Hubbard U corrections (DFT+U). The performance of ZnTe with different Cu concentrations as a BSF layer was evaluated by analysing the values of four key parameters that are open circuit voltage (VOC), short circuit current density (JSC), fill factor (FF), and conversion efficiency (η). The results indicate that an increase in Cu concentration from 0% to 3%, 6%, 10%, and 12% resulted in a reduction of the energy band gap. Specifically, the energy band gap decreased from 2.24 eV to 2.10 eV, 1.98 eV, 1.92 eV, and 1.88 eV, respectively. Optimal Cu doping promotes the favourable shift in the valence band maxima (VBM) and formation of p + -ZnTe, lowering thermionic emission and improving carrier lifetime, which results in an improved ohmic contact, η = 18.73% for 10% of Cu content. Excessive doping in contrast degraded the overall device performance by forming an unmatched carrier band offset at the front interface with CdS, increasing the acceptor type defect and CdTe compensation rate. Overall, the findings suggest that incorporating a controlled level of Cu, which in this case is around 10%, promotes the efficiency and stability of the proposed CdTe device configuration to a certain extent.
  • Publication
    Low-cost tilt monitoring system for spin coater calibration
    ( 2024-02-08)
    King C.Y.
    ;
    Mohd Fairus Ahmad
    ;
    Norhayati Sabani
    ;
    Mohd Natashah Norizan
    ;
    Nor Farhani Zakaria
    ;
    Nurjuliana Juhari
    ;
    Shamsul Amir Abdul Rais
    ;
    Amin M.R.R.M.
    The spin coating process became the most widely used technique in the fabrication industry for thin film coating on a substrate by centrifugal force. Unfortunately, frequent usage of spin coater might induce a tilted surface of the chuck (i.e. the sample holder). A tilted chuck might induce inhomogeneity of the coating layer. Among the machine's calibration techniques, nullifying the tilt before the spin coating process is the most important step. However, to our knowledge, none of the spin coaters was introduced with the chuck's tilt monitoring during the spin coating process. Thus, investigating the discrete condition during the spin coating process is necessary. In this work, the tilt monitoring system for the spin coater was implemented based on an Arduino Uno microcontroller and distance sensor. A spin coater has been implemented to test the tilt surface monitoring during spinning ranges from 350rpm to 1000rpm. The measurement was done under two conditions: flat (0.00 degrees) and tilted (5.71 degrees). The setup was able to measure up to 0.01 degrees of the tilt.
  • Publication
    First-principles investigation on the impact of copper concentration on zinc telluride as the back contact for cadmium telluride solar cells
    ( 2024-02-01)
    Ahmad N.I.
    ;
    Doroody C.
    ;
    Mohd Natashah Norizan
    ;
    Mohd Fairus Ahmad
    ;
    Rahman K.S.
    ;
    Radzwan A.
    ;
    ALOthman Z.A.
    ;
    Katubi K.M.
    ;
    Alzahrani F.M.
    ;
    Amin N.
    ;
    Kar Y.B.
    Cadmium telluride (CdTe) solar cells have attracted a lot of interest in recent years, attributed to their low cost and eco-friendly fabrication technique. However, the back contact is still the key issue for further improvement in device performance due to the work function difference between p-CdTe and metal contacts. In this study, the interatomic characteristics of zinc telluride (ZnTe) and Cu-doped ZnTe (ZnTe:Cu) as a back surface field (BSF) in CdTe structure is investigated using first-principles density functional theory (DFT) to overcome the Schottky barrier in CdTe solar cells. The incorporation of different doping levels of copper (Cu) in ZnTe on an atomic scale, where Zn1−xTe:Cux (x = 0, 2, 4, 6, 8, and 10) as the potential back surface field layers is investigated. The effect of doping concentration on electrical characteristics such as bandgap structure and density of states (DOS) were examined via ab initio with the Hubbard U (DFT + U) correction. The results showed an interesting gradual decrease in the bandgap energy of ZnTe from 2.24 eV to 2.10 eV, 1.98 eV, 1.92 eV, 1.88 eV, and 1.87 eV for the incremented value of Cu content of 3.13%, 6.25%, 9.38%, 12.50%, and 15.63%, respectively. Accordingly, it has been found that controlling of the effective copper doping, i.e., concentration, is crucial for developing efficient back contact junctions for high-efficiency CdTe thin-film solar cells.
  • Publication
    Visible Light-Assisted Charge Extraction in High-Band-Gap SrTiO3 through the Integration of a Triplet Sensitizer-Emitter Thin Film
    ( 2024-01-22)
    Jie K.V.Y.
    ;
    Mohd Fairus Ahmad
    ;
    Mohmad A.R.
    ;
    Ismail A.M.
    ;
    Mohd Natashah Norizan
    ;
    Ramli M.M.
    ;
    Safizan Shaari
    ;
    Sulaiman Y.
    ;
    Shamsul Amir Abdul Rais
    ;
    Shazlina Johari
    A challenge in PV designs, including those with an electron transport layer (ETL), is the presence of ‘parasitic absorbers’. These are layers that absorb light without significantly converting it to electrical current, impacting the total external quantum efficiency (EQE). Strontium titanate (STO), a high-band-gap (3.20 eV) perovskite metal oxide, holds promise as an electron transport layer (ETL) for solar energy harvesting. Despite STO’s potential, it primarily operates in the UV spectrum, not fully utilizing the broader light range, and hence can be the source of parasitic absorbers. In this study, we report a significant enhancement in the EQE of STO through the integration of a triplet sensitizer-emitter (TSE) system, designed to upconvert the visible spectrum into UV light and improve the charge extraction from STO. The TSE system uses carbazolyl dicyanobenzene (4CzIPN) as a sensitizer and p-terphenyl (TP) as an emitter. To investigate the EQE of such a system, we fabricate STO as a PV cell. The revised PV cell architecture (ITO/TiO2/STO/TSE/PEDOT:PSS/Al) is a modification of the conventional configurations (ITO/TiO2/STO/PEDOT:PSS/Al). With the TSE thin film, the modified STO PV cell shows better charge extraction under sunlight compared to the standard STO PV cell, indicating that the upconversion process can enhance the hole conductions from STO to PEDOT:PSS through the TSE system. We noted an EQE increase with intense light of λ > 345 nm in thicker TSE layers and a decrease in the EQE under similar light intensity in thinner TSE layers. The Kelvin probe force measurement (KPFM) data showed that the TSE layer receives holes from STO under illumination. Additionally, time-resolved photoluminescence (TRPL) experiments showed that the TSE/STO thin film is able to produce UV emission after irradiation with lower energy light. Then, the EQE variation in thicker TSE layers under intense irradiation can be attributed to the solid-state upconversion, indicating its thickness-dependent performance. These findings underline the strategies for maximizing the utilization of the solar spectrum in PV applications.
  • Publication
    Modification of Photoanode Surface Structure via Image Analysis on Organic Polymer Material based for Dye-Sensitized Solar Cell (DSSC) Applications
    ( 2021-12-01)
    Nur Liyana Mohd Rosli
    ;
    Norhayati Sabani
    ;
    Mohd Fairus Ahmad
    ;
    Mohd. Azarulsani Md. Azidin
    ;
    Nurjuliana Juhari
    ;
    Nor Farhani Zakaria
    ;
    Mohd Natashah Norizan
    ;
    Safizan Shaari
    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.
      1