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.
Main Affiliation
Scopus Author ID
57191032557
Researcher ID
AFT-7132-2022

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  • Publication
    Optimization of MEH-PPV based single and double-layer TOLED structure by numerical simulation
    ( 2021-12)
    T. Kersenan
    ;
    Nor Farhani Zakaria
    ;
    Safizan Shaari
    ;
    Norhayati Sabani
    ;
    Nurjuliana Juhari
    ;
    Meor Ahmad Faris bin Meor Ahmad Tajudin
    ;
    A.F.A Rahim
    In this work, we simulated and characterized Poly [2-methoxy-5-(2’-ethylhexyloxy)-1, 4-phenylene vinylene] (MEH-PPV) based single and double-layer TOLED by using Silvaco ATLAS device simulator to achieve prominent values of electrical and optical properties of the device. MEH-PPV were used as the emitting layer (EML) in the single-layer, while addition of Poly [(3,4-ethylene dioxythiophene)-poly(styrene sulfonate)] (PEDOT-PSS) as the electron transport layer (ETL) were conducted in double-layer TOLED simulation. The EML and ETL thickness in both structures were varied between 10 – 150 nm, respectively, to observe and understand the underlying physics of the relation in the layer thickness to the electrical and optical characteristics. Furthermore, variation of the EML/ETL thickness ratio from 1:1 to 5:1 (with thickness in between 10 to 50 nm) had also been conducted. From this work, it is understood that the thickness of the EML layer plays the most important role in TOLED, and by balancing the carrier injections and recombination rate in appropriate EML/ETL thickness ratio, the electrical and optical properties can be improved. By optimizing the EML/ETL thickness and thickness ratio, an optimal forward current of 1.41 mA and luminescent power of 1.93e-18 W/μm has been achieved with both MEH-PPV and PEDOT-PSS layer thickness of 10 nm (1:1 ratio), respectively. The results from this work will assist the improvement of TOLED device to be implemented widely in low power and transparent electronic appliances.
  • Publication
    The modelling of SiC Gate Oxide thickness based on thermal oxidation temperatures and durations for high-voltage applications
    (Walailak University, 2023)
    Nuralia Syahida Hashim
    ;
    Banu Poobalan
    ;
    Nor Farhani Zakaria
    ;
    Manikandan Natarajan
    ;
    Safizan Shaari
    This research has shown that the oxide thickness for silicon carbide (SiC) based wide materials can be predicted using regression techniques in wet/dry nitrided or wet/dry non-nitrided thermal oxidation process conditions for high voltage applications by employing 2 different regression techniques: Polynomial and linear regression. The R-squared (R2) and Mean Absolute Percentage Error (MAPE) techniques are used to evaluate the regression models. Furthermore, this work investigates and presents a calculation of gate oxide thickness that is correlated to gate voltage ranges for high voltage applications. In this work, the thermal oxidation process environment is classified into 3 different processing conditions: conventional (dry and wet), dry nitrided (NO,N2O), and wet nitrided (HNO3 vapour). The findings from this study showed that wet oxidation combined with nitrided elements can produce thicker and better-quality gate oxide as compared to conventional dry and wet oxidation techniques. The outcome of this work clearly shows that gate oxide thickness may be derived from silicon carbide-based wide-bandgap materials utilizing linear and polynomial approaches using thermal oxidation durations at different temperatures for high-power applications. The regression models and formulations produced in this work are expected to aid the researchers in determining appropriate oxide thickness under practicable process conditions, with the exception of real thermal oxidation process conditions. Hence, the outcome of this work is expected to save the processing time, material, and cost of the power semiconductor device fabrication technology, mainly for high voltage applications.
  • Publication
    Silicon Self-Switching Diode (SSD) as a Full-Wave Bridge Rectifier in 5G networks frequencies
    ( 2022)
    Tan Yi Liang
    ;
    Nor Farhani Zakaria
    ;
    Shahrir Rizal Kasjoo
    ;
    Safizan Shaari
    ;
    Muammar Mohamad Isa
    ;
    Arun Kumar Singh
    ;
    Mohd Khairuddin Md Arshad
    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.
      1  14
  • 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.
      47  5
  • 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.
      4  19
  • Publication
    Temperature effects on electrical and structural properties of MEH-PPV/PEIE OLED Device
    ( 2020-06-16)
    Nurul Afiqah Nor Ismail
    ;
    Safizan Shaari
    ;
    Mohd Fairus Ahmad
    ;
    Norhayati Sabani
    ;
    Nurjuliana Juhari
    ;
    Nor Farhani Zakaria
    This paper explores the performance of configuration ITO/MEH-PPV/PEIE/Al OLED under the variations of temperature. The MEH-PPV and MEH-PPV/PEIE thin film were deposited on ITO substrates using spin coating technique with fixed spin speed of 3000 rpm and baked at low temperature ranging from 90 °C to 180 °C, respectively. The surface roughness values for MEH-PPV and MEH-PPV/PEIE films were analysed using AFM with 5 μm ' 5 μm scanning area. The roughness of MEH-PPV thin films were reduced from 2.825 nm to 1.625 nm when temperature increased. Contrary to MEH-PPV/PEIE films where the roughness increased linearly up to 3.397 nm when the temperature increased. The maximum absorption peak spectrum obtained from UV-Visible (UV-Vis) was found at 500 nm to 510 nm when baked temperature were varied. Furthermore, the turn on voltage from J-V characteristics gives no specific pattern across different temperature and agreed with the trend of surface roughness values. The turn-on voltage at T = 150 °C gives the lowest value of 3 V. Overall, the variations of low temperature gives an effects on structural and electrical properties of this OLED configuration.
      2  27
  • 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.
      47  3
  • Publication
    Hybrid Statistical and Numerical Analysis in Structural Optimization of Silicon-Based RF Detector in 5G Network
    ( 2022-02-01)
    Yi Liang T.
    ;
    Nor Farhani Zakaria
    ;
    Shahrir Rizal Kasjoo
    ;
    Safizan Shaari
    ;
    Muammar Mohamad Isa
    ;
    Mohd Khairuddin Md Arshad
    ;
    Singh A.K.
    ;
    Sobri S.A.
    In this study, a hybrid statistical analysis (Taguchi method supported by analysis of variance (ANOVA) and regression analysis) and numerical analysis (utilizing a Silvaco device simulator) was implemented to optimize the structural parameters of silicon-on-insulator (SOI)-based self-switching diodes (SSDs) to achieve a high responsivity value as a radio frequency (RF) detector. Statistical calculation was applied to study the relationship between the control factors and the output performance of an RF detector in terms of the peak curvature coefficient value and its corresponding bias voltage. Subsequently, a series of numerical simulations were performed based on Taguchi’s experimental design. The optimization results indicated an optimized curvature coefficient and voltage peak of 26.4260 V−1 and 0.05 V, respectively. The alternating current transient analysis from 3 to 10 GHz showed the highest mean current at 5 GHz and a cut-off frequency of approximately 6.50 GHz, indicating a prominent ability to function as an RF detector at 5G related frequencies.
      4  52
  • Publication
    Hybrid statistical and numerical analysis in structural optimization of silicon-based RF Detector in 5G Network
    ( 2022-02-01)
    Tan Yi Liang
    ;
    Nor Farhani Zakaria
    ;
    Shahrir Rizal Kasjoo
    ;
    Safizan Shaari
    ;
    Muammar Mohamad Isa
    ;
    Mohd Khairuddin Md Arshad
    ;
    Arun Kumar Singh
    ;
    Sharizal Ahmad Sobri
    In this study, a hybrid statistical analysis (Taguchi method supported by analysis of variance (ANOVA) and regression analysis) and numerical analysis (utilizing a Silvaco device simulator) was implemented to optimize the structural parameters of silicon-on-insulator (SOI)-based self-switching diodes (SSDs) to achieve a high responsivity value as a radio frequency (RF) detector. Statistical calculation was applied to study the relationship between the control factors and the output performance of an RF detector in terms of the peak curvature coefficient value and its corresponding bias voltage. Subsequently, a series of numerical simulations were performed based on Taguchi’s experimental design. The optimization results indicated an optimized curvature coefficient and voltage peak of 26.4260 V−1 and 0.05 V, respectively. The alternating current transient analysis from 3 to 10 GHz showed the highest mean current at 5 GHz and a cut-off frequency of approximately 6.50 GHz, indicating a prominent ability to function as an RF detector at 5G related frequencies.
      4  3
  • Publication
    Hybrid statistical and numerical analysis in structural optimization of silicon-based RF detector in 5G network
    ( 2022-01-21)
    Tan Yi Liang
    ;
    Nor Farhani Zakaria
    ;
    Shahrir Rizal Kasjoo
    ;
    Safizan Shaari
    ;
    Muammar Mohamad Isa
    ;
    Mohd Khairuddin Md Arshad
    ;
    Arun Kumar Singh
    ;
    Sharizal Ahmad Sobri
    In this study, a hybrid statistical analysis (Taguchi method supported by analysis of variance (ANOVA) and regression analysis) and numerical analysis (utilizing a Silvaco device simulator) was implemented to optimize the structural parameters of silicon-on-insulator (SOI)-based self-switching diodes (SSDs) to achieve a high responsivity value as a radio frequency (RF) detector. Statistical calculation was applied to study the relationship between the control factors and the output performance of an RF detector in terms of the peak curvature coefficient value and its corresponding bias voltage. Subsequently, a series of numerical simulations were performed based on Taguchi’s experimental design. The optimization results indicated an optimized curvature coefficient and voltage peak of 26.4260 V−1 and 0.05 V, respectively. The alternating current transient analysis from 3 to 10 GHz showed the highest mean current at 5 GHz and a cut-off frequency of approximately 6.50 GHz, indicating a prominent ability to function as an RF detector at 5G related frequencies.
      1  8