Shamsul Amir Abdul Rais
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Preferred name
Shamsul Amir Abdul Rais
Official Name
Shamsul Amir, Abdul Rais
Alternative Name
Rais, S. A.Abdul
Rais, S. A.A.
Rais, Shamsul Amir Abdul
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Scopus Author ID
54783286700

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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.

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Investigating the magneto-transport and thermal properties of 2D electron systems under the influence of the Aharonov–Bohm field and Eckart potential interaction

2024 , C.O. Edet , K. Lakaal , J. El Hamdaoui , K. Feddi , L.M. Pérez , E. Feddi , A.N. Ikot , Norshamsuri Ali @ Hasim , Shamsul Amir Abdul Rais , M. Asjad

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Modified CMFB circuit with enhanced accuracy for data converter application

2013 , Mohd Fairus Ahmad , Sohiful Anuar Zainol Murad , Mukhzeer Mohamad Shahimin , Shamsul Amir Abdul Rais , Ahmad Fariz Hasan

Enhanced feedback voltage of common mode feedback (CMFB) circuit is designed in this work for CMOS data sampling application using 0.18-μm Silterra process technology. The double error detecting point circuit is employed to associate with the feedback point in order to prevent the undesired voltage common mode at the output of operational transconductance amplifier (OTA). The PMOS input transistor for injecting the common mode voltage is used to fit in the limitation of voltage division in low power design. The feedback voltage is strongly pushed to have a stable value as to make the outputs of differential amplifier circuit swing at a nearly constant voltage at 1.2 V for enhancing accuracy of data converter.

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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.

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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.

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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.

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A simple sensor network designed as anti-theft alarm system for copper cables

2021-05-03 , Zainol M.Z. , Mohd Natashah Norizan , Ili Salwani Mohamad , Ahmad M.F. , Shamsul Amir Abdul Rais

At present, the copper resources supply is very demanding, with society develops quickly. The increment of copper cable theft is due to the interest of its characteristic of low transmission voltage, dispersed layout, and high Cu in the material composition. The public utilities such as telecommunication providers faced plenty of troubles and dangers as they are the primary target. As a result of cable theft, the consumers cannot use the telephony system or internet services at their premises. These affect the communication between families, clients, and business purposes, including for emergency cases. Therefore, to prevent cable theft widespread, this work creates a device that is capable of alarming the responsible party when the copper at a specified location has been cut-off or tempered by thieves. A prototype has been developed for this work. Upon detection of a cable cut occurrence, this system will automatically activate the alarm and provide a display to indicate the specific location of where the cable was cut off. The system is controlled by an MCU unit (PIC16F877A). This work is using cable feeders in which the arrangement of the resistor in parallel determines the distance of the cable is terminated with the aid of the voltage divider concept.

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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.

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