Faculty of Electronic Engineering & Technology
Thumbnail Image
Parent Organisation
Country
MY
City
Pauh Putra, Perlis

Filters

Reset filters

Settings
Now showing 1 - 10 of 49
Thumbnail Image
Publication

Remazol orange dye sensitized solar cell

2017-01-03 , Siti Salwa Mat Isa , Muhammad Mahyiddin Ramli , Nor Azura Malini Ahmad Hambali , Muda M.R. , Shahrir Rizal Kasjoo , Muammar Mohamad Isa , Nurul Izza Mohd Nor , Norhawati Ahmad , Nazuhusna Khalid , Nur M. Selamat , Nur Asyikin Mohd Anhar

Water based Remazol Orange was utilized as the dye sensitizer for dye sensitized solar cell. The annealing temperature of TiO2 working electrode was set at 450 °C. The performance of the device was investigated between dye concentrations of 0.25 mM and 2.5 mM at three different immersion times (3, 12 and 24 hours). The adsorption peak of the dye sensitizer was evaluated using UV-Vis-Nir and the device performance was tested using solar cell simulator. The results show that the performance was increased at higher dye concentration and longer immersion time. The best device performance was obtained at 0.2% for dye concentration of 2.5 mM immersed at 24 hours.

View
No Thumbnail Available
Publication

Semiconducting biomass-based amorphous carbon films and their potential application in photovoltaic devices

2025 , Endhah Purwandari , Retno Asih , Sudarsono , Diky Anggoro , Gerald Ensang Timuda , Malik Anjelh Baqiya , Iman Santoso , Hideki Nakajima , Muhammad Mahyiddin Ramli , Agus Subekti , Darminto

Amorphous carbon (aC) is highly appealing because of its unique structure, electrical and optical properties, making it appropriate for various applications, especially in energy conversion. This work presents a comprehensive study on the synthesis of aC materials, including both intrinsic (i-type) and doped conditions (p- and n-type), to enhance the performance of photovoltaic films. Carbon materials are derived from biomass using a straightforward and environmentally conscious technique. The obtained carbon compound demonstrates an amorphous state with a substantial prevalence of the sp2 C=C component. Raman spectroscopy and electron microscopy confirmed the stacking of 2D layers forming a multilayer graphene structure. The carbon compound prepared AC films deposited onto a quartz glass surface via spray coating. The films have a thickness ranging from 247 to 478 nm. The dielectric constants of the optical parameters reveal resonant exciton features at a photon energy of ∼3.8 eV, whereas the real component exhibits semiconductive properties. The refractive indices of the p-, i-, and n-layers, which have gap energies in decreasing order, demonstrate a decline. The optical conductivity of aC is higher than that of amorphous silicon, specifically 0.54 × 103Ω−1cm−1, 0.48 × 103 Ω−1cm−1, and 0.53 × 103 Ω−1cm−1 for the p-, i-, and n-type films, respectively. Based on this outcome, it is reasonable to suggest that the recently developed material is potentially important as a photovoltaic device.

View
Thumbnail Image
Publication

Comprehensive study on gate recess step for the fabrication of high-speed InGaAs/InAlAs/InP pHEMT

2017-01-03 , Muammar Mohamad Isa , Norhawati Ahmad , Siti Salwa Mat Isa , Muhammad Mahyiddin Ramli , Nazuhusna Khalid , Nurul Izza Mohd Nor , Shahrir Rizal Kasjoo , Missous M.

We report a comprehensive etching study on the gate recess step for the fabrication of the novel high speed pHEMT devices. The experiments focused on the elimination of 'hump' structure as a result of an incomplete etching process at the InGaAs cap layer. In this work, two types of test samples were used, namely bulk InGaAs and epitaxial structure together with an etch stop layer. The result showed that the etch rate of bulk InGaAs is about 360 A/min and the percentage of dome height is consistent at approximately 25%. Meanwhile, the study on pHEMT epitaxial layer showed that the etching time of 3 minutes is sufficient in order to completely remove the cap layer. Gate leakage current of magnitude more than 10 times lower is observed on the devices that engaging Succinic Acid as the gate recess etching agent. The optimized processing steps will tailor for highly reproducible pHEMT fabrication process for high speed applications.

View
No Thumbnail Available
Publication

Review—Charge carrier mobility of organic thin film transistor: intrinsic and extrinsic influencing factors based on organic semiconducting materials

2023 , Nur Zuraihan Abd Wahab , Abdullah Abdulhameed , Ahmad Ghadafi Ismail , Muhammad Mahyiddin Ramli , Roslina Mohd Sidek , Suhaidi Shafie , Mohd Nazim Mohtar

The use of organic thin film transistors (OTFTs) is growing rapidly as an alternative to their inorganic counterparts due to their advantageous properties, such as easy processing and flexibility. The performance of OTFTs is still undergoing improvement and taking this as a recognition, this paper reviews various factors that influence the performance of the OTFTs, primarily in terms of field-effect mobility. The influencing factors reviewed in this article are divided into intrinsic and extrinsic factors for different organic semiconducting materials (OSMs). The intrinsic factors include the OSMs’ molecular orientation, OSM/dielectric interaction, and OSM/electrode interaction. The extrinsic factors are basically related to the OSM processing and OTFTs fabrication. For example, the article discusses how mixing, blending, and annealing affect the properties of the OSMs. The effect of the ambient atmosphere on OTFTs’ performance is also discussed. The aim of this article is to discuss the current trends related to one of the critical figures of merit of OTFTs, which is the mobility of charge carriers.

View
Thumbnail Image
Publication

Single wall carbon nanotubes dispersion study of different dye molecules and chitosan

2017-09-26 , Muhammad Mahyiddin Ramli , Siti Salwa Mat Isa , Mohd. Mustafa Al Bakri Abdullah , Sohiful Anuar Zainol Murad

Carbon Nanotubes (CNTs) is known for their hydrophobicity ability. However, this ability can become the bottleneck for the application of CNTs where a highly dispersion of materials are needed. In this project, different dispersing agents were investigated namely dye molecules and chitosan. Three different dyes are studied with different concentration, including 0.05 % of chitosan. The dispersion quality is determined by examining through UV-Vis-NIR. The best dispersion quality investigated here is when the concentration of dye molecules is higher, which is around 2.5 mM.

View
No Thumbnail Available
Publication

Binding dynamics and conformational stability of graphene-based nanomaterials with Mutant LOX-1: Insights from molecular docking and dynamics simulations in atherosclerosis

2024-12 , Farizah Hanim Lat , Ahmad Naqib Shuid , Mohd Yusmaidie Aziz , Muhammad Mahyiddin Ramli , Rafeezul Mohamed

Oxidized low-density lipoprotein (oxLDL) is a critical factor in endothelial dysfunction and serves as an important biomarker for oxidative stress. Recent research has focused on lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1), a receptor for oxLDL that plays a significant role in atherosclerosis progression. Mutant LOX-1 may show changes in its binding affinity for oxLDL, potentially leading to variations in oxLDL uptake and foam cell formation. Our previous investigation into graphene-based nanomaterials and their interactions with atherosclerosis-related proteins, including LOX-1, provided important insights into their binding characteristics. In this study, we delve deeper into the binding dynamics between graphene-based nanomaterials and mutant LOX-1, aiming to clarify their implications for atherosclerotic development. Using molecular docking techniques with AutodockVina and active site predictions from P2Rank, we evaluated the binding affinities of graphene, graphene oxide (GO), and reduced graphene oxide (rGO) to mutant LOX-1. Notably, all docking scores were below -5 kcal/mol, indicating strong interactions with the receptor. To investigate the dynamics of these interactions further, we performed molecular dynamics (MD) simulations using the CHARMM force field. Our simulations revealed significant conformational changes within the first 100 ns, particularly in the mutant LOX-1 and GO complex, which suggested improved binding stability. These results enhance our understanding of how graphene-based nanomaterials interact with mutant forms of LOX-1, offering potential avenues for targeted therapies in atherosclerosis management related to LOX-1 dysregulation.

View
Thumbnail Image
Publication

Interdigitated electrodes as impedance and capacitance biosensors: A review

2017-09-26 , Mazlan N. , Muhammad Mahyiddin Ramli , Mohd. Mustafa Al Bakri Abdullah , Dewi Suriyani Che Halin , Isa S. , Talip L. , Nuaim Siddiqi Danial , Sohiful Anuar Zainol Murad

Interdigitated electrodes (IDEs) are made of two individually addressable interdigitated comb-like electrode structures. IDEs are one of the most favored transducers, widely utilized in technological applications especially in the field of biological and chemical sensors due to their inexpensive, ease of fabrication process and high sensitivity. In order to detect and analyze a biochemical molecule or analyte, the impedance and capacitance signal need to be obtained. This paper investigates the working principle and influencer of the impedance and capacitance biosensors. The impedance biosensor depends on the resistance and capacitance while the capacitance biosensor influenced by the dielectric permittivity. However, the geometry and structures of the interdigitated electrodes affect both impedance and capacitance biosensor. The details have been discussed in this paper.

View
No Thumbnail Available
Publication

Effect of soaking time towards graphitization of empty fruit bunch (EFB) waste

2023 , Norizah Abd Karim , Che Mohd Ruzaidi Ghazali , Muhammad Mahyiddin Ramli , Marniati , Zulfadhli, M. R.M. , Mutiawati

Empty fruit bunch (EFB) are the second-highest waste produced in the oil palm industry which is 18 022 tonnes in a year. However, the presence of oil palm waste especially from empty fruit bunch (EFB) give a major problem to the disposal. Herein, EFB waste has been identified as a potential carbon source for synthetic graphite production. This is due to implement the lower heating temperature of synthetic graphite produced in controlled heating conditions. Several parameters have been manipulated to study the effect of various parameters on the graphitization process. Hence, in this study, the effect of soaking time towards graphitization of empty fruit bunch (EFB) waste has been investigated. EFB waste was heat treated with various soaking times which is 2 hours, 2.5 hours and 3 hours in controlled heating conditions with constant heating temperature at 500°C and heating rate at 10°/minute After heating treatment, the samples were characterized using X-ray Diffraction (XRD) and analyzed by X'Pert Highscore Plus software. The functional group of synthetic graphite was determined by using Fourier Transform Infrared spectroscopy (FTIR). The morphological study was carried out by using Scanning Electron Microscope (SEM). From the analysis, the best synthetic graphite produced is at the 2.5 hours soaking time with a constant heating temperature at 500°C and a constant heating rate at 10°/min.

View
No Thumbnail Available
Publication

Biomass Waste Incorporation in La₀.₆Sr₀.₄Co₀.₂Fe₀.₈O₃-α˗Ba(Ce₀.₆Zr₀.₄)₀.₉Y₀.1O₃-δ composite cathode: effects on microstructural and physical properties

2025 , Ismariza Ismail , Nur Ashafieka Abdullah , Norizah Abd Karim , Shazlina Johari , Muhammad Mahyiddin Ramli

This study explores the incorporation of rice straw as a pore-forming agent in fabricating the Laâ‚€.₆Srâ‚€.â‚„Coâ‚€.â‚‚Feâ‚€.₈O₃-α˗Ba(Ceâ‚€.₆Zrâ‚€.â‚„)â‚€.₉Yâ‚€.1O₃–δ (LSCF-BCZY) composite cathode, focusing on its microstructural and physical properties. Conventional cathode materials often face challenges in balancing porosity and structural stability, with synthetic pore formers posing environmental and consistency concerns. To address these issues, rice straw was introduced into the cathode matrix at varying weight percentages, and the composites were sintered at 1000 Â°C. The addition of rice straw was evaluated using X-ray diffraction, scanning electron microscopy, and densitometry. The results revealed that increasing rice straw content significantly enhanced cathode porosity, rising from 5.53 to 27.74%, with a concomitant reduction in density from 1.33 to 0.93 g/cm3, while maintaining the crystalline stability of the LSCF-BCZY composite. Enhanced porosity suggests improved reactant diffusion to active sites, potentially benefiting the cell's performance in future energy applications. This work highlights the potential of agricultural waste as a sustainable and effective alternative to synthetic pore formers in cathode fabrication.

View
Thumbnail Image
Publication

Effect of polyethylene glycol and sodium dodecyl sulphate on microstructure and self-cleaning properties of graphene oxide/TiO2 thin film

2020-09-01 , Azani A. , Dewi Suriyani Che Halin , Kamrosni Abdul Razak , Mohd. Mustafa Al Bakri Abdullah , Norsuria Mahmed , Muhammad Mahyiddin Ramli , Mohd Arif Anuar Mohd Salleh , Mohd Fairul Sharin Abdul Razak , Ayu Wazira Azhari , Chobpattana V. , Kaczmarek L.

In this study, a sol gel procedure for preparation of TiO2 thin films with graphene oxide (GO) was developed. The effect of PEG and SDS addition on the microstructure of the films as well as the photocatalytic activity of the thin film was also investigated. The morphology and surface structure of the films were studied by SEM and AFM while the photocatalytic activity of the films was analyzed by measuring the degradation of methylene blue under sunlight irradiation using UV-Vis spectrophotometer. It was found that GO/TiO2 thin film with PEG shows a smaller and porous particle while GO/TiO2 thin film with SDS formed a very smooth surface and very fine particles. Therefore, in AFM analysis reveals that surface roughness decreases with the addition of PEG and SDS. Finally, the photocatalytic activity showed that GO/TiO2 thin film with SDS have the most effective self-cleaning property which degrade 64% of methylene blue that act as model of contaminants.

View