Ili Salwani Mohamad

Dye-Sensitized Solar Cells Using Natural Dyes as Sensitizers From Malaysia Local Fruit 'Buah Mertajam'

We experimentally demonstrate the high conversion efficiency, low cost, green technology and easy to fabricate dye-sensitized solar cells (DSSCs) using natural anthocyanin dyes as sensitizers. The DSSCs was fabricated by using natural anthocyanin dyes which were extracted from different parts of the plants inclusive ‘Buah Mertajam’, ‘Buah Keriang Dot’, ‘Bunga Geti’, Hibiscus, Red Spinach and Henna. The natural anthocyanin dyes that found in flower, leaves and fruits were extracted by the simple procedures. This anthocyanin dye is used to replace the expensive chemical synthetic dyes due to its ability to effectively attach into the surface of Titanium dioxide (TiO2). A natural anthocyanin dyes molecule adsorbs to each particle of the TiO2 and acts as the absorber of the visible light. A natural anthocyanin dye from Buah Mertajam shows the best performance with the conversion efficiency of 5.948% and fill factor of 0.708 followed by natural anthocyanin dyes from ‘Buah Keriang Dot’, ‘Bunga Geti’, Hibiscus, Red Spinach and Henna. Buah Mertajam or scientifically known as eriglossum rubiginosum is a local Malaysia fruit.

Non-Dominated Sorting Genetic Algorithm in Optimizing Ninth Order Multiple Feedback Chebyshev Low Pass Filter

Optimization for complex circuit design often requires large amount of manpower and computational resources. In order to optimize circuit performance, it is critical not only for circuit designers to adjust the component value but also to fulfill objectives such as gain, cutoff frequency, ripple and etc. This paper proposes Non-dominated Sorting Genetic Algorithm II (NSGA-II) to optimize a ninth order multiple feedback Chebyshev low pass filter. Multi-objective Pareto-Based optimization is involved whereby the research aims to obtain the best trade-off for minimizing the pass-band ripple, maximizing the output gain and achieving the targeted cut-off frequency. The developed NSGA-II algorithm is executed on the NGSPICE circuit simulator to assess the filter performance. Overall results show satisfactory in the achievements of the required design specifications.

Organic Solar Cell: An Overview on Performance and Fabrication Techniques

This paper review based on the organic solar cell (OSC). In this review we investigates on the performance perspectives and theoretical of the solar cell using both simulation and spin coating fabrication technique. This paper reviews on progress several organic materials which use as active layer and issues on device efficiencies. This paper also review on development in device structure to get desired higher output in OSC.

Effects of Indium (In) to the Efficiency Tandem Cell Ga1-xInxP/Silicon for Solar Cell Application

In this paper, the contribution of Indium (In) to the Gallium Phosphide (GaP) composition of solar cell was investigated to know the effectiveness of the In when its being substitute to GaP layer on the top layer of Silicon (Si) substrate. The substitution was made to the Ga1-xInxP for the range of (0≤x≤0.5). The highest efficiency was 10.1235% for x=0.5 for the Ga1-xInxP. In contribution shows a higher efficiency compared to single layer GaP which only about 5.40608%. As the x composition increased, the efficiency becomes higher for each composition increment. The rate of efficiency, increased about 88% and improves current density with a value up to 13.1134mA/cm2.The efficiency obtained in this work is considerably high using simulation tools compared to the previous record for InGaP/Silicon reported in Feb 2014 about 6~11.2% by fabrication method.

GSM remote sensing for copper cable transmission line monitoring system using FPGA

Copper cable is used as a medium of communication whether for a fixed telephone line or internet service. Currently, the price of copper increases due to a high demand of global trading market. As a consequence, telephone cable stealing activities in Malaysia are also increased due to the copper used inside the telephone cable. Therefore, this project presents the works in designing and developing an innovative apparatus that will be able to help the local telecommunication company to monitor and detect not only the area or location of loss signal occurred but also the distance of the telephone cable being cut. This system applies the FPGA-based monitoring system using GSM (Global System for Mobile) network. 555 timer is used as a capacitance detector to detect the frequency value of the copper cable. The Altera DE2-70 board in the other hand is used to calculate the cable distance, which influenced by the cable frequency. After detecting an occurrence of a cable has been cut, this prototype will automatically activate an alarm signal and send an instant message (SMS) to alert the person in charge indicating the area and distance of the cable that has been cut.

The Effect of Temperature on Anatase TiO2 Photoanode for Dye Sensitized Solar Cell

Dye sensitized solar cell (DSSC) is a well-known photovoltaic device that is used for low power application. One of the main components for DSSC is semiconductor material photoanode which will provide the pathway for electron transportation and thus determine the energy conversion efficiency of the DSSC. The most commonly used material for the semiconductor photoanode is titanium dioxide (TiO2). TiO2 is a semiconductor material with wide bandgap material that is existed in three crystalline phase; rutile, anatase and brookite. This paper emphasizes the best annealing temperature for commercialized TiO2, 98% anatase powder where the temperature varies from 300 oC – 600 oC. Through this research, the best annealing temperature for anatase TiO2 photoanode is at 420 °C (0.094%) with the crystallite size of 18.76 nm and particle size of 19 nm that is favorable for the dye attached and thus enhances the energy conversion efficiency of the DSSC.

The Comparison Between Gallium Arsenide and Indium Gallium Arsenide as Materials for Solar Cell Performance Using Silvaco Application

The work presented in this paper is about the development of single and multilayer solar cells using GaAs and InGaAs in AM1.5 condition. The study includes the modeling structure and simulation of the device using Silvaco applications. The performance in term of efficiency of Indium Gallium Arsenide (InGaAs) and GaAs material was studied by modification of the doping concentration and thickness of material in solar cells. The efficiency of the GaAs solar cell was higher than InGaAs solar cell for single layer solar cell. Single layer GaAs achieved an efficiency about 25% compared to InGaAs which is only 2.65% of efficiency. For multilayer which includes both GaAs and InGaAs, the output power, Pmax was 8.91nW/cm² with the efficiency only 8.51%. GaAs is one of the best materials to be used in solar cell as a based compared to InGaAs.

Fabrication and characterization of ZnO:In thin film as photoanode for DSSC using natural fruit dyes

Dye synthesized solar cell (DSSC) is the third generation solar cell and is considered as low cost solar cell as it does not involved neither complicated fabrication process nor expensive materials. DSSC is made of two conductive glasses, photoanode, counter electrode, electrolyte and dye. Previously, majority of the researchers have been using titanium dioxide and ruthenium as the photoanode and dye respectively. This project is carried out to produce a lower cost DSSC by using natural fruit as the dye and exploring the potential of zinc oxide (ZnO) and indium (In) as the photoanode. The morphology of the thin film surfaces were analyzed using scanning electron microscopy which shows that the increment of indium dopant changes the rough surface texture of the thin film and directly reduces the empty spaces between the particles. Theoretically, this structure can help to reduce the light reflection on the solar cell surface. The thin ZnO:In films are immersed in 3 different fruit dyes (plum, apple and orange). The electrical properties of the DSSCs are displayed in the I-V curves and from this research, it shows that the highest efficiency of DSSC is gained from the dopant combination of ZnO0.8In0.2 for all the dyes. The best efficiency of this research is the DSSC using plum dye with 0.34% compared to apple dye and orange dye which give 0.23% and 0.19% respectively.Dye synthesized solar cell (DSSC) is the third generation solar cell and is considered as low cost solar cell as it does not involved neither complicated fabrication process nor expensive materials. DSSC is made of two conductive glasses, photoanode, counter electrode, electrolyte and dye. Previously, majority of the researchers have been using titanium dioxide and ruthenium as the photoanode and dye respectively. This project is carried out to produce a lower cost DSSC by using natural fruit as the dye and exploring the potential of zinc oxide (ZnO) and indium (In) as the photoanode. The morphology of the thin film surfaces were analyzed using scanning electron microscopy which shows that the increment of indium dopant changes the rough surface texture of the thin film and directly reduces the empty spaces between the particles. Theoretically, this structure can help to reduce the light reflection on the solar cell surface. The thin ZnO:In films are immersed in 3 different fruit dyes (plum, apple and ora...

Ferroelectric and relaxor ferroelectric to paralectric transition based on Lead Magnesium Niobate (PMN) materials

First ferroelectric materials were found in Rochelle salt was in a perovskite structure. Lead Magnesium Niobate (PMN) is a perovskites with a formula of PbMg1/3Nb2/3O3 (PMN) and are typical representatives for most of all ferroelectrics materials with relaxor characteristic. It posses high dielectric permittivity which nearly ~ 20,000[ with a broad dielectric permittivity characteristic, known as relaxor ferroelectric below room temperature. Some of the researcher might think that the transition from relaxor ferroelectric to paraelectric is similar to the characteristic as observed from ferroelectric to paraelectric, but it is not necessary. The puzzling is how do we categorise them. How is the domain structure look like typically in ceramic materials.