http://dspace2020.uniten.edu.my:8080/handle/123456789/5 Scholarly Publication from UNITEN Community (College of Engineering) 2026-07-11T17:47:41Z http://dspace2020.uniten.edu.my:8080/handle/null Title: Degradation of perovskite thin films and solar cells with candle soot c/ag electrode exposed in a control ambient Authors: Islam M.A.; Mohafez H.; Sobayel K.; Hatta S.F.W.M.; Hasan A.K.M.; Khandaker M.U.; Akhtaruzzaman M.; Muhammad G.; Amin N. Abstract: Perovskite solar cells (PSCs) have already achieved efficiencies of over 25%; however, their instability and degradation in the operational environment have prevented them from becom-ing commercially viable. Understanding the degradation mechanism, as well as improving the fabrication technique for achieving high-quality perovskite films, is crucial to overcoming these short-comings. In this study, we investigated details in the changes of physical properties associated with the degradation and/or decomposition of perovskite films and solar cells using XRD, FESEM, EDX, UV-Vis, Hall-effect, and current-voltage (I-V) measurement techniques. The dissociation, as well as the intensity of perovskite peaks, have been observed as an impact of film degradation by humidity. The decomposition rate of perovskite film has been estimated from the structural and optical changes. The performance degradation of novel planner structure PSCs has been investigated in detail. The PSCs were fabricated in-room ambient using candle soot carbon and screen-printed Ag electrode. It was found that until the perovskite film decomposed by 30%, the film properties and cell efficiency remained stable. © 2021 by the authors. Licensee MDPI, Basel, Switzerland. 2021-01-01T00:00:00Z http://dspace2020.uniten.edu.my:8080/handle/123456789/21675 Title: DC traction power substation using eighteen-pulse rectifier transformer system Authors: Toh C.L.; Tan C.W. Abstract: Twelve-pulse rectification system had been widely integrated in today’s DC traction power sub-station (DC-TPSS). This configuration had successfully mitigated low order harmonic distortion. As some research findings had confirmed that the DC voltage and current ripple factors may further minimize by increasing the number of rectification pulses to 18, 24, or 36. This paper had presented a simulation study to investigate the prospect of implementing an eighteen-pulse rectification system in a DC-TPSS. The theory of phase-shifting transformer used to produce an 18-pulse rectifier is presented with simulation verification. Simulation result shows that 3.69% of grid current distortion index is recorded without installing any filters. In addition, the DC voltage and current ripple may also be further reduced for about 30% compared to a conventional twelve-pulse rectification system. © 2021, Institute of Advanced Engineering and Science. All rights reserved. 2021-01-01T00:00:00Z http://dspace2020.uniten.edu.my:8080/handle/123456789/18778 Title: Synthesis of sphere-like-crystal CdS powder and thin films using chemical residue in chemical bath deposition (CBD) for thin film solar cell application Authors: Ameen M. Ali; Nowshad Amin; Shahidan Radiman; Kamaruzzaman Sopian; Halina Misran; Lamya M. Ali; Yulisa Yusoff Abstract: CdS microcrystal, with sphere like morphology, was synthesised from the residue obtained after the chemical bath deposition (CBD) of CdS thin layers usually deposited for CdTe and/or CIGS thin film solar cells, specifically by recycling the chemical waste. The residue was collected and reused to deposit cadmium sulphide (CdS) thin films on glass substrate by thermal evaporation. The films were subsequently annealed in vacuum at 250 °C, 350 °C and 420 °C for 40 min. The structural and optical properties were characterized by XRD, SEM, and UV–Vis spectrometry. All the films were found to exhibit high transmittance (over 70 to 90%). The optical band gap energy was found to be in the range of 2.28–2.37 eV, which is very suitable to be used as buffer or window for CdTe or CIGS thin film solar cells. 2018-01-01T00:00:00Z http://dspace2020.uniten.edu.my:8080/handle/123456789/11430 Title: Fast voltage collapse evaluation via fuzzy decision tree method Authors: Abidin, H.I.H.Z.; Lo, K.L.; Hussein, Z.F. Abstract: Voltage stability is considered to be a complex field of study since it has a number of contributing factors. Due to this, numerous studies or research has been made to look into various methods of analysis, detection and mitigation. In general, these methods would involve either complex computation for accurate results but suffers from high computation time. Some methods may also be simple and fast but then has the disadvantage of inaccuracy. This paper presents an alternative method of analysing the voltage stability problem by incorporating machine learning techniques, i.e. fuzzy decision tree method. The author proposed a general overview on how the algorithm is created. The algorithm is then tested using an IEEE 300 bus test system to test the algorithm's capability. Results presented show that the proposed FDT has a lot of future potential as an online tool for voltage stability analysis. © 2003 IEEE. 2003-01-01T00:00:00Z