Shahrir Rizal Kasjoo
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Preferred name
Shahrir Rizal Kasjoo
Official Name
Shahrir Rizal, Kasjoo
Alternative Name
Kasjoo, S.
Kasjoo, Shahrir R.
Kasjoo, S. R.
Shah K.
Main Affiliation
Scopus Author ID
36809748400
Researcher ID
ABI-6061-2020

Research Output

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  • 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.
  • Publication
    Noise Properties of Unipolar Nanodiodes at Elevated Temperatures
    ( 2021-12-01)
    Shahrir Rizal Kasjoo
    ;
    Singh A.K.
    ;
    Balocco C.
    ;
    Song A.
    A unipolar nanodiode known as the self-switching diode has been demonstrated as a room-temperature terahertz detector, with its noise-equivalent-power value comparable to those of the state-of-the-art Schottky diodes. Here, we study its performance at elevated temperatures and show an unusual reduction in low-frequency noise, which may be useful for practical applications. The experiments suggest that the increased thermionic emissions result in the reduced device resistance and hence the lowered noise. The observed noise behavior appears to be in good agreement with Hooge’s mobility fluctuation theory.
  • 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
    Graphene self-switching diode-based thermoelectric rectifier
    ( 2020-09-30)
    Kaushal B.
    ;
    Garg S.
    ;
    Prakash K.
    ;
    Shahrir Rizal Kasjoo
    ;
    Kumar S.
    ;
    Gupta N.
    ;
    Singh A.K.
    This Letter demonstrates thermoelectric rectification in graphene self-switching diode (GSSD) on SiO2/Si substrate. Nanometre-scale nonlinear semiconductor device, called self-switching diode (SSD), has been utilised. Applied bias leads to a change in potential profile and effective channel width of GSSD resulting in diode like I-V characteristics. The excellent electronic properties of graphene potentially make it suitable for producing SSD's with high responsivity and low noise equivalent power (NEP). The designed GSSD demonstrates a high Seebeck coefficient (S) of 200 μV/K, voltage detection sensitivity, and NEP of 97.964 V/W and 0.6064 nW/Hz1/2, respectively. Furthermore, the effect of applying backgate voltage on the Seebeck coefficient has also been demonstrated in this work. The GSSD is presented as a potential thermoelectric rectifier, which can convert the thermal energy into useful electrical energy.
  • Publication
    Low voltage low power FGMOS based current mirror
    ( 2017-11-22)
    Nurulain D.
    ;
    Musa F.A.S.
    ;
    Muammar Mohamad Isa
    ;
    Norhawati Ahmad
    ;
    Shahrir Rizal Kasjoo
    This paper presents the comparison of a conventional current mirror with the one utilizing floating gate MOSFET transistors (FGMOS) to achieve low power (LP) and low voltage (LV) design. The device structure has been simulated with 0.1μ CMOS technology and 1.2V voltage supply by using SAED 90nm PDK with the Synopsys Custom Designer tool. The FGMOS circuit has shown to have low power consumption of 9.62mW, smaller threshold voltage of 0.2V and Iout of 20 mA. The improvement of 40.1% from conventional current mirror has shown the LV and LP capability of FGMOS transistor.
  • Publication
    Self-switching diodes as RF rectifiers: Evaluation methods and current progress
    ( 2019-06-01)
    Zakaria N.
    ;
    Shahrir Rizal Kasjoo
    ;
    Isa M.
    ;
    Zarimawaty Zailan
    ;
    Arshad M.
    ;
    Sanna Taking
    In the advancement of the Internet of Things (IoT) applications, widespread uses and applications of devices require higher frequency connectivity to be explored and exploited. Furthermore, the size, weight, power and cost demands for the IoT ecosystems also creates a new paradigm for the hardware where improved power efficiency and efficient wireless transmission needed to be investigated and made feasible. As such, functional microwave detectors to detect and rectify the signals transmitted in higher frequency regions are crucial. This paper reviewed the practicability of self switching diodes as Radio Frequency (RF) rectifiers. The existing methods used in the evaluation of the rectification performance and cut-off frequency are reviewed, and current achievements are then concluded. The works reviewed in this paper highlights the functionality of SSD as a RF rectifier with design simplicity, which may offer cheaper alternatives in current high frequency rectifying devices for application in low-power devices.
  • Publication
    TCAD simulation of AlGaN/GaN HEMT grown on high-resistivity silicon substrate
    ( 2024-02-08)
    Sanna Taking
    ;
    Ofiare A.
    ;
    Ahmad N.
    ;
    Musa A.Z.
    ;
    Sendekisager K.
    ;
    Isa M.M.
    ;
    Shahrir Rizal Kasjoo
    ;
    Wasige E.
    This paper studies GaN device structure on silicon substrates. The fabricated device, with LG of 4-μm and WG of 100-μm, demonstrates a maximum drain current of 780mA/mm and a threshold voltage of - 4V. The two-dimensional Silvaco simulator tools are used to analyze and model the fabricated device. The simulation results closely match the experimental findings, validating the developed model's accuracy. These outcomes signify that the study can be a reference for modeling other GaN-based devices in future material growth and process development.
  • Publication
    Non-linear analysis of Self-Switching Diodes as microwave rectifiers
    ( 2017-01-01)
    Shahrir Rizal Kasjoo
    ;
    Zulfadhli Zailan
    ;
    Sanna Taking
    ;
    Wan Zuki Azman Wan Muhamad
    ;
    Muammar Mohamad Isa
    ;
    Arshad M.
    A planar device known as the Self-Switching Diode (SSD) has been demonstrated as a high-speed rectifier, up to terahertz frequencies. The rectifying properties of SSD are dependent on a nonlinear current-voltage characteristic of the device. In this research, the rectification of two SSD rectifiers has been reported and their performances were evaluated. The observed results showed a good agreement with the nonlinear theoretical analysis of both rectifiers by means of a Taylor series which can be utilized in improving the rectifying performance of any diode-based rectifier specifically for diodes with tunable threshold voltage such as SSDs.
  • Publication
    Analysis on square and circular inductor for a high Q-factor inductor
    ( 2021-12)
    Aimi Noorliyana Hashim
    ;
    Nazuhusna Khalid
    ;
    Nurul Izza Mohd Nor
    ;
    Shahrir Rizal Kasjoo
    ;
    Zaliman Sauli
    This paper presents the high-quality (Q) factor inductors using Silicon-on-sapphire (SOS) for the 10GHz to 20GHz frequency band. Inductors are designed on SOS because of their advantages, including high resistivity and low parasitic capacitance. This paper compares square and circular inductor topologies for high-quality (Q) factor inductors using HFSS software for the high-frequency band. Both inductors have been designed with the same width and thickness to make them comparable with each other. The comparison shows that a circular inductor achieves the highest Q-factor. Furthermore, the circular and square inductor's Q-factor, inductance, and resistance are analyzed. As a result, the circular inductor has the maximum Q-factor of 89.34 at 10.6GHz for 0.29nH, while the square inductor has obtained a maximum Q-factor of 80.72 at 10GHz for 0.40nH inductance.
  • Publication
    InGaAs Self-Switching Diode With Suppressed Harmonics For High Frequency Applications
    ( 2023-01-01)
    Sharma B.
    ;
    Garg S.
    ;
    Singh P.
    ;
    Garg S.
    ;
    Das G.
    ;
    Sharma D.K.
    ;
    Gupta N.
    ;
    Singh A.K.
    ;
    Kumar S.
    ;
    Shahrir Rizal Kasjoo
    In this study, a novel InGaAs-based nano- rectifier known as self-switching diode is presented to exhibit the suppressed harmonics for high frequency applications. The self-switching diode device exhibits current-voltage characteristics analogous to the conventional diodes, eliminating the need for a p-n junction and/or Schottky barrier. The direct and alternating current characteristics of the proposed device are investigated by filling its trenches with different dielectric materials. Further, the total harmonic distortion is quantified by implementing Fast Fourier Transform to estimate the corresponding harmonic components. The results suggest the introduction of dielectric materials with permittivity ranging from 1.0 to 9.3 into the trenches results in the significant reduction in total harmonic distortion from 69% to 60.4% at high frequencies.