Browsing by Author "Al-Dhlan, Kawther A"

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Bandwidth Broadening of Piezoelectric Energy Harvesters Using Arrays of a Proposed Piezoelectric Cantilever Structure
(MDPI AG, 8/17/2021) Salem, Marwa S; Ahmed, Shimaa; Shaker, Ahmed; Alshammari, Mohammad T; Al-Dhlan, Kawther A; Alanazi, Adwan; Saeed, Ahmed; Abouelatta, Mohamed
One of the most important challenges in the design of the piezoelectric energy harvester is its narrow bandwidth. Most of the input vibration sources are exposed to frequency variation during their operation. The piezoelectric energy harvester’s narrow bandwidth makes it difficult for the harvester to track the variations of the input vibration source frequency. Thus, the harvester’s output power and overall performance is expected to decline from the designed value. This current study aims to solve the problem of the piezoelectric energy harvester’s narrow bandwidth. The main objective is to achieve bandwidth broadening which is carried out by segmenting the piezoelectric material of the energy harvester into n segments; where n could be more than one. Three arrays with two, four, and six beams are shaped with two piezoelectric segments. The effect of changing the length of the piezoelectric material segment on the resonant frequency, output power, and bandwidth, as well as the frequency response is investigated. The proposed piezoelectric energy harvesters were implemented utilizing a finite element method (FEM) simulation in a MATLAB environment. The results show that increasing the number of array beams increases the output power and bandwidth. For the three-beam arrays, at n equals 2, 6 mW output power and a 9 Hz bandwidth were obtained. Moreover, the bandwidth of such arrays covered around 5% deviation from its resonant frequency. All structures were designed to operate as a steel wheel safety sensor which could be used in train tracks. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
Comprehensive design and analysis of thin film Sb2S3/CIGS tandem solar cell: TCAD simulation approach
(IOP Publishing Ltd, 2024-06) Salem, Marwa S; Shaker, Ahmed; Aledaily, Arwa N; Alanazi, Adwan; Al-Dhlan, Kawther A; Okil, Mohamed
This research presents a design and analysis of a tandem solar cell, combining thin film wide bandgap Sb2S3 (1.72 eV) and narrow bandgap CIGS (1.15 eV) for the top and bottom sub-cells, respectively. The integration of all thin film layers enhances flexibility, rendering the tandem solar cell suitable for applications such as wearable electronics. To optimize the power conversion efficiency (PCE) of the tandem solar device, advanced technology computer-aided design (TCAD) simulation tools are employed to estimate loss mechanisms and fine-tune parameters for each layer. An experimentally validated optoelectronic model is introduced, calibrated and validated against fabricated reference solar cells for the individual top and bottom cells. The calibrated model is then utilized to propose optimization routines for the Sb2S3/CIGS tandem solar cell. The initial tandem cell exhibits a JSC of 15.72 mA cm−2 and a PCE of 15.36%. The efficiency drop in the tandem configuration is identified primarily in the top cell. A systematic optimization process for the top cell is initiated, exploring various configurations, including HTL-free and ETL-free setups. Moreover, an np homojunction structure for the top cell is proposed. Optimization routines are applied that involve determining optimal thickness and doping concentration of the n-layer, investigating the effect of p-layer doping concentration, and exploring the influence of the work function of the front contact. As a result, the tandem cell efficiency is significantly improved to 23.33% at the current matching point (CMP), with a J SC of 17.15 mA cm−2. The findings contribute to the advancement of thin-film tandem solar cell technology, showcasing its potential for efficient and flexible photovoltaic applications .
Design considerations of CdSe solar cells for indoor applications under white LED illumination
(Elsevier B.V, 2024-07) Salem, Marwa S; Shaker, Ahmed; Okil, Mohamed; Li, Luying; Chen, Chao; Aledaily, Arwa N; Al-Dhlan, Kawther A; Zekry, Abdelhalim
This work sheds light on the potential of Cadmium Selenide (CdSe) solar cells for indoor applications. CdSe boasts a wide direct bandgap, high carrier mobility, and a high absorption coefficient, making it an attractive candidate for harnessing ambient indoor light. Our study centers around an experimental solar cell architecture composed of FTO/CdSe/PEDOT:PSS/CuI/ITO, which exhibits a power conversion efficiency (PCE) of 6.00 %. Through a meticulous analysis of the core technological aspects of this cell, we successfully replicate the measured current-voltage characteristics and other experimental data, affirming the validity of our simulation modeling approach. Moving forward, we delve into the design and optimization of CdSe-based solar cells under white LED illumination. We emphasize the pivotal role of a double-hole transport layer (HTL) configuration over a single HTL, with a focus on optimizing the alignment between the HTL/back contact and HTL/absorber interfaces. The strategic incorporation of a heavily doped p-type HTL material, boasting both a deep valence band maximum (VBM) and a shallow conduction band minimum (CBM), is identified as paramount, especially for a deep VBM absorber like CdSe. Adding double HTL materials also facilitates efficient hole collection within the CdSe thin film while mitigating undesirable electron-hole recombination at the critical interface between the hole collection layer and the electrode. The implementation of a double HTL configuration based on CuI/ZnTe:Cu or CuI/BCS significantly enhances performance, resulting in a PCE in the order of 20 % under 200 lux and 2900 K LED illumination. Moreover, we introduce the single HTL design to provide other alternatives for efficiency boosting. Upon increasing the work function of the front contact, it is found that the valence band offset between the HTL and the absorber can be engineered, resulting in a PCE above 21.5 %.
Influence of base doping level on the npn microstructure solar cell performance: A TCAD study
(Elsevier B.V., 2021-11) Salem, Marwa; Zekry, A; Abouelatta, M; Alshammari, Mohammad T; Alanazi, Adwan; Al-Dhlan, Kawther A; A.Shaker, A
Optical Materials Volume 121, November 2021, 111501 Short Communication Influence of base doping level on the npn microstructure solar cell performance: A TCAD study Author links open overlay panelMarwaSalemabA.ZekrycM.AbouelattacMohammad T.AlshammaridAdwanAlanazidKawther A.Al-DhlandA.Shakere a Department of Computer Engineering, Computer Science and Engineering College, University of Ha'il, Ha'il, Saudi Arabia b Department of Electrical Communication and Electronics Systems Engineering, Faculty of Engineering, Modern Science and Arts University (MSA), Cairo, Egypt c Department of Electronics and Communications, Faculty of Engineering, Ain Shams University, Cairo, Egypt d Department of Computer science and information, Computer Science and Engineering College, University of Ha'il, Ha'il, Saudi Arabia e Department of Engineering Physics and Mathematics, Faculty of Engineering, Ain Shams University, Cairo, Egypt Received 5 April 2021, Revised 16 August 2021, Accepted 18 August 2021, Available online 24 August 2021. crossmark-logo https://doi.org/10.1016/j.optmat.2021.111501 Get rights and content Highlights • Device simulation of proposed npn microstructure solar cell was comprehensively performed. • The impact of base high doping on the device performance was fully discussed. • The results show that for NB ranging from 5 × 1017 cm−3 to 2 × 1019 cm−3, the cell could achieve a competitive efficiency, from 15.4% to 9%, respectively. • For base doping ranging from 5×1017 cm-3 to 2×1019 cm-3, a competitive efficiency is 15.4% to 9%, respectively. Abstract Silicon industry has a mature learning curve which is the driver for 90% share of the PV market. Yet, the cost/m2 of the planar crystalline silicon solar cell is still high. To reduce the cost of silicon-based solar cells, heavily doped wafers can be used in a proposed npn microstructure in which photoexcited carries are vertically generated while the collection of carriers is accomplished in the lateral direction. In this work, we report on the influence of the heavily p + base doping concentration, Na, on the performance of the cell for different base widths. All simulations are performed by using SILVACO TCAD under AM1.5 illumination. The results show that for Na extending from 5 × 1017 cm−3 to 2 × 1019 cm−3, the cell could achieve a competitive efficiency, from 15.4% to 9%, respectively.
Numerical analysis of hole transport layer-free antimony selenide solar cells: Possible routes for efficiency promotion
(Elsevier, 2022-07) Salem, Marwa S; Shaker, Ahmed; Abouelatta, M; Alanazi, Adwan; Al-Dhlan, Kawther A; Almurayziq, Tariq S
Amongst the numerous absorbers confronted in thin-film solar cell technology, antimony selenide (Sb2Se3) is regarded as an extremely promising contender as it is a non-toxic and earth-abundant besides its high-level absorption coefficient. To boost the power conversion efficiency (PCE) of Sb2Se3 solar cells, we report some design recommendations by utilizing device simulation. The device model is firstly validated by calibration of an experimental cell having a configuration of FTO/CdS/Sb2Se3/Spiro-OMeTAD/Au. Then, the optimization of a hole transport layer (HTL) free structure is carried out by tuning the conduction band offset between the electron transport layer (ETL) and the Sb2Se3 absorber and by inspecting the key absorber parameters to get the maximum available power conversion efficiency. In this context, the ternary compound material ZnMgO is found to match the optimum band alignment. Moreover, the impact of ETL parameters, like thickness, doping, and surface treatment by ammonia etching, has been analyzed to understand its underlying physics and to provide possible ways for device efficiency promotion. All simulations, conducted in this paper, are accomplished by SCAPS device simulation software under standard one Sun (AM1.5G, 100 mW/cm2) illumination at 300 K.
On the Investigation of Interface Defects of Solar Cells: Lead-based vs Lead-free Perovskite
(IEEE Access, 2021) Salem, Marwa. S; Salah, Mostafa M; Mousa, Mohamed; Shaker, Ahmed; Zekry, Abdelhalim; Abouelatta, Mohamed; Alshammari, Mohammad T; Al-Dhlan, Kawther A; Gontrand, Christian
Perovskite solar cells (PSCs) have drawn significant consideration as a competing solar cell technology because of the drastic advance in their power conversion efficiency (PCE) over the last two decades. The interfaces between the electron transport layer (ETL) and the absorber layer and between the absorber layer and the hole transport layer (HTL) have a major impact on the performance of the PSCs. In this paper, we have investigated the defect interfaces between ETL/absorber layer and absorber layer/HTL of calibrated experimental lead-based and lead-free PSCs. The influence of the defect interfaces is studied in order to find the optimum value for the maximum possible PCE. While the PCE has not been enhanced considerably for the lead-based, it is boosted from 1.76% to 5.35% for lead-free PSCs. Also, bulk traps were found to have minor role in comparison with interface traps for the lead-free cell while they have a significant impact for the lead-based cell. The results presented in this work would shed some light on designing interface defects of various types of practical PSC structures and demonstrates the crucial impact of the interface defects on lead-free vs lead-based PSCs. All simulation studies are performed by using SCAPS-1D simulator.