Now showing 1 - 10 of 11
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Synthesis Methods of Tin Oxide as Photoanode for Dye-Sensitized Solar Cell Performance: A Short Review

2021-12-01 , Idris S.N. , Mohd Natashah Norizan , Ili Salwani Mohamad , Norsuria Mahmed , Magiswaran K. , Sobri S.A.

This review focused on the synthesis methods of tin oxide (SnO2) nanoparticles as a photoanode for dye-sensitized solar cell (DSSC) and how it impacts the performance. There are many different techniques and various nanoparticles were produced and usually characterized by X-ray diffraction (XRD) to determine crystalline structure of SnO2, scanning electron microscopy (SEM) to examine the surface morphology and size details and J-V solar simulator to verify current-voltage characteristics. In summary, considering all the methods reviewed, sol-gel is reported as the best method to produce SnO2 nanoparticles for DSSC fabrication with the highest efficiency recorded of 3.96%.

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Elucidating the Effects of Interconnecting Layer Thickness and Bandgap Variations on the Performance of Monolithic Perovskite/Silicon Tandem Solar Cell by wxAMPS

2023-06-01 , Ili Salwani Mohamad , Doroody C. , Alkharasani W.M. , Mohd Natashah Norizan , Chelvanathan P. , Shahahmadi S.A. , Amin N.

In this study, we investigated the pathways for integration of perovskite and silicon solar cells through variation of the properties of the interconnecting layer (ICL). The user-friendly computer simulation software wxAMPS was used to conduct the investigation. The simulation started with numerical inspection of the individual single junction sub-cell, and this was followed by performing an electrical and optical evaluation of monolithic 2T tandem PSC/Si, with variation of the thickness and bandgap of the interconnecting layer. The electrical performance of the monolithic crystalline silicon and CH3NH3PbI3 perovskite tandem configuration was observed to be the best with the insertion of a 50 nm thick (Eg ≥ 2.25 eV) interconnecting layer, which directly contributed to the optimum optical absorption coverage. These design parameters improved the optical absorption and current matching, while also enhancing the electrical performance of the tandem solar cell, which benefited the photovoltaic aspects through lowering the parasitic loss.

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Electrical Performance of Curcuma longa Extract Dye using SnO2-Based Photoanode Dye-Sensitized Solar Cell

2022-12-01 , Siti Norhafizah Idris , Ili Salwani Mohamad , Norsuria Mahmed , Mohd Natashah Norizan , Magiswaran K. , Abas Z.A.

Due to their low output costs, straightforward manufacturing, and high effectiveness, dye-sensitized solar cell (DSSC) has a large following interest in the solar energy industry. Furthermore, due to its outstanding properties, tin oxide (SnO2) is an appealing semiconducting material suitable as a photoanode in DSSCs. In this research, the photoelectrodes of DSSC were fabricated using commercial SnO2 nanoparticles and sensitized with inorganic and organic dyes, N719 and Curcuma longa (turmeric) extract dye. On top of that, a platinum (Pt) counter electrode, iodide electrolyte and fluorine-doped tin oxide (FTO) coated glass substrate were used to fabricate the DSSC. The crystallographic structure and surface morphology of the SnO2 nanopowder were identified using X-ray diffraction (XRD) and scanning electron microscopy (SEM) characterizations respectively. In addition, UV-Visible and current density-voltage curves were used to analyze the optical properties of the photoanodes and the cell’s electrical performance. As a result, it was found that the DSSC fabricated with N719 dye exhibited higher efficiency in contrast with the turmeric extract dye with SnO2 photoanodes.

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Magnetic-Based Coreshell Nanoparticles as Potential Adsorbents for the Removal of Cu2+ under Ultraviolet (UV) Light

2021-11-12 , Husni H.N. , Norsuria Mahmed , Ge Y. , Mohd Natashah Norizan , Dewi Suriyani Che Halin , Kamrosni Abdul Razak , Ili Salwani Mohamad

The magnetite (Fe3O4) and maghemite (gFe2O3) nanoparticles, magnetite-silica-silver chloride (Fe3O4-SiO2-AgCl) and maghemite-silica-silver chloride (gFe2O3-SiO2-AgCl) coreshell structures have successfully been synthesized by using a simple wet chemistry method. The efficiency of these particles as the adsorbents for the removal of copper ion, Cu2+ in aqueous solution under UV light was investigated. Two different parameters were studied, namely the adsorbents contact time (60, 120, 180, 240 and 300s) and the solution-stirring rate (100, 200 and 300 rpm). From the results, the removal percentage of the copper ions from the solution were above 90% after 5 hours of adsorption process at 300 rpm by using Fe3O4 (94%) and gFe2O3 (92%) nanoparticles. The maximum removal of copper ions was nearly 100% when gFe2O3-SiO2-AgCl & Fe3O4-SiO2-AgCl coreshell particles were used. The samples that were prepared without magnetic core such as AgCl-SiO2, AgCl and SiO2 particles, showed lower percentage of the copper ions removal (78%, 60% and 20%, respectively). This situation shows that the magnetic nanoparticles plays and important role during the adsorption process due to their large active sites for the adsorption to occur.

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Analysis of Symmetric Two and Four-coil Magnetic Resonant Coupling Wireless Power Transfer

2022-04-01 , Ali A. , Mohd Najib Mohd Yasin , Rambe A.H. , Ismahayati Adam , Ramli N. , Hasliza A Rahim @ Samsuddin , Thennarasan Sabapathy , Mohd Natashah Norizan , Sobri S.A.

This study examined the efficiency of power transfer for two-coil and four-coil spiral magnetic resonant coupling wireless power transfer (WPT) using distance to coil diameter (D/dm) ratio and reflection coefficient, S21 value. Adding resonators reduced the total resistance in the two-coil WPT system while increasing the S21 values of the whole system. A same-size spiral coil was proposed for the system and simulated using computer simulation technology (CST). A prototype with similar specifications for a four-coil design was implemented for verification. The proposed method yielded an optimal efficiency of 76.3% in the four-coil system, while the two-coil WPT yielded a 23.2% efficiency with a 1.33 D/dm ratio.

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Copper doping effect in the back surface field layer of CdTe thin film solar cells

2024-02-01 , Nur Irwany Ahmad , Kiong T.S. , Doroody C. , Rahman K.S. , Mohd Natashah Norizan , Mohd Fairus Ahmad , Kar Y.B. , Harif M.N. , Amin N.

In this work, the Solar Cell Capacitance Simulator (SCAPS-1D) is employed to evaluate the characteristics of CdTe thin films with ZnTe as the Back Surface Field (BSF) layer and estimate the effective copper doping ratio at both the atomic scale and the device operational response perspective. The electrical characteristics of ZnTe, at varying levels of copper doping, were derived using density functional theory (DFT) by applying the generalized gradient approximation (GGA) and Hubbard U corrections (DFT+U). The performance of ZnTe with different Cu concentrations as a BSF layer was evaluated by analysing the values of four key parameters that are open circuit voltage (VOC), short circuit current density (JSC), fill factor (FF), and conversion efficiency (η). The results indicate that an increase in Cu concentration from 0% to 3%, 6%, 10%, and 12% resulted in a reduction of the energy band gap. Specifically, the energy band gap decreased from 2.24 eV to 2.10 eV, 1.98 eV, 1.92 eV, and 1.88 eV, respectively. Optimal Cu doping promotes the favourable shift in the valence band maxima (VBM) and formation of p + -ZnTe, lowering thermionic emission and improving carrier lifetime, which results in an improved ohmic contact, η = 18.73% for 10% of Cu content. Excessive doping in contrast degraded the overall device performance by forming an unmatched carrier band offset at the front interface with CdS, increasing the acceptor type defect and CdTe compensation rate. Overall, the findings suggest that incorporating a controlled level of Cu, which in this case is around 10%, promotes the efficiency and stability of the proposed CdTe device configuration to a certain extent.

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The Effect of Spinacia oleracea Dye Absorption Time on ZnO-based Dye-Sensitized Solar Cells’ Electrical Performance

2022-12-01 , Magiswaran K. , Ili Salwani Mohamad , Norsuria Mahmed , Mohd Natashah Norizan , Idris S.N. , Abas Z.A.

Dye-sensitized solar cells (DSSC) have attracted much attention over the past 20 years due to their significance in energy conversion. However, the dye soaking time may significantly impact the efficacy of the photoanode semiconductor to carry the electronic charge to which the dye molecules adhere. An optimized dye soaking time may prevent the recombination of photo-excited electrons that are injected into the semiconductor of the DSSC. This study scrutinized the dependence of the zinc oxide (ZnO) photoanode soaking time of Spinacia oleracea (spinach) dye on the photocurrent-voltage characteristics. The ZnO film layer (photoanode) was prepared with commercial ZnO nanopowder and applied onto a fluorine-doped tin oxide (FTO) glass substrate using the doctor blade method. The prepared DSSCs’ were subjected to a variety of characterizations, including current density-voltage (J-V) characterization, UV-visible characterization, scanning electron microscope (SEM), and X-ray diffraction (XRD). Comparing four variations of dye soaking time, ZnO-based DSSC photoanode soaked in the dye for an hour achieved an optimum efficiency of 0.03 %. This study proved that the efficiency of a DSSC can be improved by optimizing the dye soaking time.

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Comparative analysis on virtual private network in the internet of things gateways

2022-10-01 , Zakaria M.I. , Mohd Natashah Norizan , Muammar Mohamad Isa , Jamlos M.F. , Mustapa M.

A virtual private network (VPN) connects a private network to the internet, primarily the public network, through a secure tunnel. Using a local area network (LAN) segment, users can send and receive data from their colleagues in different locations on the network. The development of VPN allows users to gain access to company applications and databases. Therefore, data can be transmitted through a secure tunnel without the need to configure port forwarding for the internet of things (IoT) gateway, allowing users to access it from any location in the world. A method such as dataplicity and pitunnel was examined to compare with the conventional setting. This research paper examines the current deployment of VPN connections in IoT gateways, discussing their characteristics, benefits, and drawbacks, as well as comparing them. The advantage of this method is that the IoT gateway is always accessible and has internet connectivity, which is a significant benefit. Dataplicity is a more trustworthy option because they offer excellent assistance for both the backend and frontend environments.

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First-principles investigation on the impact of copper concentration on zinc telluride as the back contact for cadmium telluride solar cells

2024-02-01 , Ahmad N.I. , Doroody C. , Mohd Natashah Norizan , Mohd Fairus Ahmad , Rahman K.S. , Radzwan A. , ALOthman Z.A. , Katubi K.M. , Alzahrani F.M. , Amin N. , Kar Y.B.

Cadmium telluride (CdTe) solar cells have attracted a lot of interest in recent years, attributed to their low cost and eco-friendly fabrication technique. However, the back contact is still the key issue for further improvement in device performance due to the work function difference between p-CdTe and metal contacts. In this study, the interatomic characteristics of zinc telluride (ZnTe) and Cu-doped ZnTe (ZnTe:Cu) as a back surface field (BSF) in CdTe structure is investigated using first-principles density functional theory (DFT) to overcome the Schottky barrier in CdTe solar cells. The incorporation of different doping levels of copper (Cu) in ZnTe on an atomic scale, where Zn1−xTe:Cux (x = 0, 2, 4, 6, 8, and 10) as the potential back surface field layers is investigated. The effect of doping concentration on electrical characteristics such as bandgap structure and density of states (DOS) were examined via ab initio with the Hubbard U (DFT + U) correction. The results showed an interesting gradual decrease in the bandgap energy of ZnTe from 2.24 eV to 2.10 eV, 1.98 eV, 1.92 eV, 1.88 eV, and 1.87 eV for the incremented value of Cu content of 3.13%, 6.25%, 9.38%, 12.50%, and 15.63%, respectively. Accordingly, it has been found that controlling of the effective copper doping, i.e., concentration, is crucial for developing efficient back contact junctions for high-efficiency CdTe thin-film solar cells.

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Comparative analysis on virtual private network in the internet of things gateways

2022-10-01 , Mohd Idzaney Zakaria , Mohd Natashah Norizan , Muammar Mohamad Isa , Mohd Faizal Jamlos , Mustapa Muslim

A virtual private network (VPN) connects a private network to the internet, primarily the public network, through a secure tunnel. Using a local area network (LAN) segment, users can send and receive data from their colleagues in different locations on the network. The development of VPN allows users to gain access to company applications and databases. Therefore, data can be transmitted through a secure tunnel without the need to configure port forwarding for the internet of things (IoT) gateway, allowing users to access it from any location in the world. A method such as dataplicity and pitunnel was examined to compare with the conventional setting. This research paper examines the current deployment of VPN connections in IoT gateways, discussing their characteristics, benefits, and drawbacks, as well as comparing them. The advantage of this method is that the IoT gateway is always accessible and has internet connectivity, which is a significant benefit. Dataplicity is a more trustworthy option because they offer excellent assistance for both the backend and frontend environments.