Nor Farhani Zakaria
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Nor Farhani Zakaria
Official Name
Nor Farhani, Zakaria
Alternative Name
Zakaria, N. Fa
Zakaria, N. F.
Zakaria, N.
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Scopus Author ID
57191032557
Researcher ID
AFT-7132-2022

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  • Publication
    Application of Taguchi method in optimization of structural parameters in self-switching diode to improve the rectification performance
    ( 2020-01-08)
    Nor Farhani Zakaria
    ;
    Shahrir Rizal Kasjoo
    ;
    Muammar Mohamad Isa
    ;
    Zarimawaty Zailan
    ;
    Mokhar M.B.M.
    ;
    Juhari N.
    This paper presents the use of Taguchi method in the optimization process of a Self-switching Diode (SSD) as a Terahertz rectifier to obtain the optimal parameters for rectification. The rectification performance is mainly contributed by a parameter known as curvature coefficient, γ which is derived from the current-voltage (I-V) behavior of the device and can be altered by varying the device's geometrical structure. The parameters involved are the channel length, channel width and trenches width of the device, and the rectification performance are observed based on the peak of γand its corresponding bias voltage. Using Taguchi method for design of experiment (DOE), effects on the interaction among these parameters are investigated by employing the orthogonal array and evaluation of the signal-to-noise (S/N) ratio both in the peak of γand its corresponding bias voltage. The proposed parameters using this method showed γ peak of 32 V-1 and 30 V-1 at DC bias of 30 mV and zero-bias, respectively.
  • 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
    An overview of semiconductor rectifier operating in the millimeter wave and terahertz region
    ( 2020-01-08)
    Mohd Mokhar, Mohd Bazli
    ;
    Shahrir Rizal Kasjoo
    ;
    Nurjuliana Juhari
    ;
    Nor Farhani Zakaria
    An imaging system operated at millimeter (MM) waves and terahertz (THz) frequencies can be used in many applications such as safety monitoring, public security, medical, healthcare and manufacturing. Typically, these systems utilize rectifying antenna (rectenna) to convert electromagnetic radiation into usable DC power which will be used to generate images. One of the main components of rectenna is the rectifier. Hence, this paper explores the current review on several semiconductor rectifiers that have been significantly deployed for MM-wave/THz imaging systems. This includes Schottky diodes, metal-insulator-metal (MIM) diodes, self-switching diodes (SSDs) and ballistic rectifiers (BRs). The rectifying performance of these devices are discussed in terms of their voltage responsivity and noise-equivalent power (NEP). The standard fabrication process of each device is also presented in this paper as well as their recent development and achievement as high-frequency rectifiers for MM-wave/THz imaging systems.
  • Publication
    Simulation and characterization of an inverter logic gate by utilizing InGaAs-based planar devices
    ( 2023-12)
    Faradilla Aziz
    ;
    Shahrir Rizal Kasjoo
    ;
    Nor Farhani Zakaria
    ;
    Fauzi Packeer
    ;
    A. K. Singh
    Electronic circuits known as logic gates can perform basic logical operations like inverters, AND, and OR gates. These logic gates serve as the basis for digital electronics, and they are a common component in various electronic devices, such as computers, smartphones, and other types of digital systems. This research presents an inverter logic gate made of planar devices, which have significantly simpler structures than multi-layered transistors and diodes, namely the self-switching diode (SSD) and side-gated transistor (SGT). The inverter logic gate is realized by simply connecting both SSD and SGT in parallel. The electrical characteristics and performances of the inverter logic gate are assessed based on InGaAs material using SILVACO Inc.'s ATLAS device simulator software. The simulation results show that the functionality of the proposed planar inverter is comparable to that of a conventional inverter logic gate based on the standard truth table of the device. This has demonstrated the feasibility of building logic gates using a combination of SSDs and SGTs. In addition, the planar structure of SSD and SGT allows for a relatively low-cost device fabrication process as well as offering a high-frequency operation due to low parasitic elements in the devices.
  • Publication
    A brief overview of detectors used for terahertz imaging systems
    ( 2020-01-08)
    Shahrir Rizal Kasjoo
    ;
    Mohd Mokhar, Mohd Bazli
    ;
    Nor Farhani Zakaria
    ;
    Nurjuliana Juhari
    This paper presents a short review on terahertz imaging systems based on several types of technology used in the terahertz detection schemes. Some commercial products from ThruVision Systems Limited Company have utilized GaAs Schottky diode detector at 0.25 THz to produce passive terahertz images for public and homeland security. On the other hand, TeraSense Group Incorporated Company has developed and invented a ground-breaking technology which employs sensor consisting of a matrix of plasmonic semiconductor detectors in their latest products to generate terahertz images in the 0.1 - 1.0 THz frequency range. Recently, the utilization of two-terminal unipolar nanodiodes, known as the self-switching diodes (SSDs), as terahertz detectors has shown promising results. The planar structure of SSD not only enables the device to operate at high frequencies due to low intrinsic parasitic capacitance, but also allows the realization of the device using only a single lithography step. This makes the fabrication process of SSDs faster, more simple, and at lower cost when compared to other electronic devices such as Schottky diodes. The development and recent achievement of SSDs as terahertz detectors are also presented in this paper.
  • Publication
    Photoluminescence measurement of triplet sensitizer-emitter solution using a customized 3D-printed sample holder
    ( 2024-06)
    Kelvin Voon Yan Jie
    ;
    Safizan Shaari
    ;
    Mohd Fairus Ahmad
    ;
    Nor Farhani Zakaria
    ;
    Norhayati Sabani
    This study explores the photoluminescence (PL) measurement of triplet sensitizer-emitter (TSE) solutions using a custom 3D-printed sample holder, within the context of triplet-triplet annihilation based molecular photon upconversion (TTA-UC) systems targeting the Vis-to-UV spectral region. TTA-UC converts low-energy visible photons to higher-energy ultraviolet (UV) photons, holding promise for solar energy harvesting and photonics applications. Two TSE couples, 4CzIPN/TP and 4CzIPN/QP, were investigated, and their upconverted fluorescence spectra showed peaks at 344 nm and 354 nm / 370 nm, respectively, confirming efficient upconversion capabilities. The 3D-printed sample holder facilitated reproducible PL measurements, enabling the calculation of quantum yields (ΦUC). The 4CzIPN/TP and 4CzIPN/QP couples exhibited low quantum yields (0.028% and 0.043%, respectively), suggesting the need for improved deoxygenation methods to enhance the triplet-triplet annihilation process and overall quantum efficiency. Despite modest yields, successful UV upconverted fluorescence observation underscores the feasibility of the Vis-to-UV TTA-UC system. This study provides insights into TTA-UC optimization and demonstrates the utility of the 3D-printed sample holder for affordable and precise PL measurements, paving the way for future advancements in photonics and solar energy 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
    The structural and electrical characterization of PEDOT:PSS/MEH-PPV doped with PEIE OLED fabricated using spin coating technique
    ( 2020-01-08)
    Juhari N.
    ;
    Shukri N.I.A.
    ;
    Norhayati Sabani
    ;
    Safizan Shaari
    ;
    Mohd Fairus Ahmad
    ;
    Nor Farhani Zakaria
    This paper investigates the performance of the uniformity and absorption spectrum of MEHPPV+PEIE thin films also the electrical properties for configuration of ITO/PEDOT: PSS/MEH+PEIE/Al. The sample used 0.5 wt % of PEDOT: PSS solution while 5 mgml-1 concentration of MEH-PPV solution was doped with four different concentrations of PEIE with values of 0.1 wt%, 0.3 wt%, 0.5 wt% and 0.7 wt% respectively. The untreated PEDOT: PSS and MEH-PPV+PEIE was deposited using spin coating technique at a fixed spun speed of 3000 rpm to obtain smooth surface roughness thin film. The root mean square (RMS) value, absorption spectrum and current density (A/cm-2) of the PEDOT: PSS and MEH-PPV+PEIE films were analyzed using Atomic Force Microscope (AFM), UV-Visible (UV-Vis) Spectrophotometer and Semiconductor Parametric Analyzer (SPA), respectively. The surface roughness of the films were linearly increased when the dopant concentration increased with the maximum RMS value of ∼4.74 nm. Besides, absorption peak wavelength also was red-shifted from 500 nm to 551 nm under an influence of PEIE dopant concentrations. However, the turn on voltage gives no significant trend when dopant concentration was increased but the emission of the light was emitted when the voltage was below 8 V. Among four different dopant concentrations of MEH-PPV+PEIE, the brighter light emission was observed at 0.3 wt% of PEIE. Apparently, the concentration of dopant solution gives a significant contribution to the performance of OLED in terms of structural, optical and electrical properties.
  • Publication
    Design and simulation of InGaAs-based planar electronic nanodevices as terahertz rectifiers based on curvature coefficient analysis
    ( 2019)
    Nor Farhani Zakaria
    The “Terahertz gap” frequencies between 0.1 to 10 THz possess unique characteristics with a lot of promising application in various fields such as safe imaging, medical and explosive detections. However, limited numbers of optimal (current responsivity, β > 3.5 V-1) detectors and sources in this region leave researchers only a few alternatives in exploring the region. In this work, characterizations using ATLAS device simulator aimed to increase β performance of Self-switching Diode (SSD) and simulations of new planar devices; the Planar Barrier Diode (PBD) and Self-switching Planar Barrier Diode (SSPBD) are reported. The β is mainly contributed by a parameter known as the curvature coefficient, γ which is derived from the current-voltage (I-V) behavior of the device. As such, the γ was analyzed in this work, not only by varying the device’s geometrical structure, but also by implementing different dielectric relative permittivity of the insulating material ranging from 1.0 – 10 under temperature range of 300 – 600 K. The results showed that increased temperature degraded the SSD’s and PBD’s rectifying performance due to increased reverse current which can deteriorate the nonlinearity of the device’s I-V characteristic. For SSD, the γ of ~32 V-1 and 30 V-1 has been achieved at 30 mV and zero-bias, respectively. The cut-off frequency, fc of SSD attained in this work was ~80 GHz, operating at unbiased condition. In addition, an enhanced barrier is introduced in the new PBD device, which contributed to higher switching speed in the channel. The working principle of the new PBD is explained using thermionic emission theory. By employing the optimized structure parameters, the zero-bias γ of ~4 V-1, with peak of ~14 V-1 at 0.10 V bias were achieved. With DC bias of 50 mV to exploit the rectification peak, the fc of the PBD was attained at 270 GHz. In addition, hybrid structure of SSPBD shows improved performance in fc with detection of 360 GHz at zero-bias. Zero-bias γ of ~6 V-1, with peak of ~19 V-1 at 70 mV bias were observed in the SSPBD. The β of >3.5 V-1 in all simulated devices indicates optimal conversion ability as a rectifying device. The results obtained in this work proved the functionality of SSD as mm-wave rectifiers, and the new devices of PBD and SSPBD as THz rectifiers and may assist in future improvement of the devices.
  • Publication
    Silicon Self-Switching Diode (SSD) as a Full-Wave Bridge Rectifier in 5G Networks Frequencies
    ( 2022-12-01)
    Yi Liang T.
    ;
    Nor Farhani Zakaria
    ;
    Shahrir Rizal Kasjoo
    ;
    Safizan Shaari
    ;
    Muammar Mohamad Isa
    ;
    Mohd Khairuddin Md Arshad
    ;
    Singh A.K.
    The rapid growth of wireless technology has improved the network’s technology from 4G to 5G, with sub-6 GHz being the centre of attention as the primary communication spectrum band. To effectively benefit this exclusive network, the improvement in the mm-wave detection of this range is crucial. In this work, a silicon self-switching device (SSD) based full-wave bridge rectifier was proposed as a candidate for a usable RF-DC converter in this frequency range. SSD has a similar operation to a conventional pn junction diode, but with advantages in fabrication simplicity where it does not require doping and junctions. The optimized structure of the SSD was cascaded and arranged to create a functional full-wave bridge rectifier with a quadratic relationship between the input voltage and outputs current. AC transient analysis and theoretical calculation performed on the full-wave rectifier shows an estimated cut-off frequency at ~12 GHz, with calculated responsivity and noise equivalent power of 1956.72 V/W and 2.3753 pW/Hz1/2, respectively. These results show the capability of silicon SSD to function as a full-wave bridge rectifier and is a potential candidate for RF-DC conversion in the targeted 5G frequency band and can be exploited for future energy harvesting application.