Browsing by Author "Abouelatta, Mohamed"

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Analysis of Hybrid Hetero-Homo Junction Lead-Free Perovskite Solar Cells by SCAPS Simulator
(MDPI, 09/12/2021) Salem, Marwa. S; Shaker, Ahmed; Zekry, Abdelhalim; Abouelatta, Mohamed; Alanazi, Adwan; Alshammari, Mohammad T; Gontand, Christian
In this work, we report on the effect of substituting the active intrinsic i-layer on a conventional pin structure of lead-free perovskite solar cell (PSC) by a homo p-n junction, keeping the thickness of the active layer constant. It is expected that when the active i-layer is substituted by a p-n homo junction, one can increase the collection efficiency of the photo-generated electrons and holes due to the built-in electric field of the homo junction. The impact of the technological and physical device parameters on the performance parameters of the solar cell have been worked out. It was found that p-side thickness must be wider than the n-side, while its acceptor concentration should be slightly lower than the donor concentration of the n-side to achieve maximum efficiency. In addition, different absorber types, namely, i-absorber, n-absorber and p-absorber, are compared to the proposed pn-absorber, showing a performance-boosting effect when using the latter. Moreover, the proposed structure is made without a hole transport layer (HTL) to avoid the organic issues of the HTL materials. The back metal work function, bulk trap density and ETL material are optimized for best performance of the HTL-free structure, giving Jsc = 26.48, Voc = 0.948 V, FF = 77.20 and PCE = 19.37% for AM1.5 solar spectra. Such results highlight the prospective of the proposed structure and emphasize the importance of using HTL-free solar cells without deteriorating the efficiency. The solar cell is investigated by using SCAPS simulator.
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.
Design of power efficient routing protocol for smart livestock farm applications
(ASTES Publishers, 2020-12) Abou Emira, Shahenda S; Youssef, Khaled Y; Abouelatta, Mohamed
The demand on livestock as a source of protein is increasing with the dramatic increase of world population which approaches 8 billion. As a result, the monitoring of the performance of livestock breeding is becoming essential. The technique which could increase livestock production and improve the efficiency of operation is digitalization of livestock management.This could be achieved by models' realization that relates the rates of productivity and the parameters of operation which count on collecting big volume of data that results from digitalization process. In fact, the adoption of IoT technology in livestock environments is usually challenged by energy problems and power efficient communication technologies. In this paper a modified AODV protocol is proposed to enhance the traditional AODV protocol used in MANET networks that was mainly concerned with optimal route selection based on shortest path to send the data packets through it. The proposed technique models and simulates operational parameters of intermediate nodes as a factor to decide on the optimal path selection in IoT based MANET networks in addition to the shortest path that leads to transmission power gain of the source node. The results show a significant power performance enhancement that reaches average power saving of 33.3% compared to the traditional AODV protocol. © 2020 ASTES Publishers. All rights reserved
Full optoelectronic simulation of all antimony chalcogenide thin film tandem solar cell: Design routes from 4-T to 2-T configuration
(Ain Shams University, 2024-06) Salem, Marwa S; Shaker, Ahmed; Chen, Chao; Li, Luying; Abouelatta, Mohamed; Aledaily, Arwa N; Zein, Walid; Okil, Mohamed
Antimony chalcogenide, as a newcomer to light harvesting materials, is regarded as an auspicious contender for incorporation as a photoactive layer in thin film tandem solar cells (TFTSCs). The current study introduces the design of all-antimony chalcogenide TFTSC comprised of an Sb2S3 (1.7 eV) front subcell and an Sb2Se3 (1.2 eV) rear subcell. The challenges to migrating from four-terminal (4-T) to two-terminal (2-T) designs are highlighted and possible solutions are proposed. To commence, a calibration procedure for the two subcells is conducted in alignment with experimental investigations. The benchmarked solar cells yield a power conversion efficiency (PCE) of 8.08 % for the upper subcell and 10.58 % for the lower subcell. Subsequently, upon integration of both subcells within the initial 4-T Sb2S3/Sb2Se3 TFTSC, the resultant PV cell attains a PCE of 12.27 %. Before transitioning it to a more efficient 2T tandem configuration, we explore alternative inorganic HTL materials to the Spiro-OMeTAD HTL to overcome its practical considerations. Cu2O is found to be the best HTL alternative to be included for both subcells. Upon stacking into the tandem structure, the combined cell exhibited an efficiency of 15.68 % and a notable Jsc of 16.23 mA/cm2 . To further enhance the tandem performance, the device structure is optimized by engineering the CBO of two sub-cells and employing a double ETL design for the front sub-cell. At the considered current matching criterion, the tandem device PCE and Jsc are boosted to 27.86 % and 17.60 mA/ cm2 , respectively. Based on this full optoelectronic analysis, developed in the Silvaco TCAD environment, a 2-T all antimony chalcogenide tandem configuration can be realized and optimized, paving the way for future experimental endeavors.
Full Optoelectronic Simulation of Lead-Free Perovskite/Organic Tandem Solar Cells
(MDPI AG, 2023-02) Salem, Marwa S; Shaker, Ahmed; Abouelatta, Mohamed; Saeed, Ahmed
Organic and perovskite semiconductor materials are considered an interesting combination thanks to their similar processing technologies and band gap tunability. Here, we present the design and analysis of perovskite/organic tandem solar cells (TSCs) by using a full optoelectronic simulator (SETFOS). A wide band gap lead-free ASnI2Br perovskite top subcell is utilized in conjunction with a narrow band gap DPPEZnP-TBO:PC61BM heterojunction organic bottom subcell to form the tandem configuration. The top and bottom cells were designed according to previous experimental work keeping the same materials and physical parameters. The calibration of the two cells regarding simulation and experimental data shows very good agreement, implying the validation of the simulation process. Accordingly, the two cells are combined to develop a 2T tandem cell. Further, upon optimizing the thickness of the front and rear subcells, a current matching condition is satisfied for which the proposed perovskite/organic TSC achieves an efficiency of 13.32%, Jsc of 13.74 mA/cm2 , and Voc of 1.486 V. On the other hand, when optimizing the tandem by utilizing full optoelectronic simulation, the tandem shows a higher efficiency of about 14%, although it achieves a decreased Jsc of 12.27 mA/cm2 . The study shows that the efficiency can be further improved when concurrently optimizing the various tandem layers by global optimization routines. Furthermore, the impact of defects is demonstrated to highlight other possible routes to improve efficiency. The current simulation study can provide a physical understanding and potential directions for further efficiency improvement for lead-free perovskite/organic TSC.
On design of IoT-based power quality oriented grids for industrial sector
(ASTES Publishers, 2021-01) Gomaa, Nesma N; Youssef, Khaled Y; Abouelatta, Mohamed
Manufacturing industry is facing several challenges in power quality and energy consumptions that play a significant role in the cost of goods sold in addition to the operational efficiency of manufacturing plants. The current techniques are not enough to manage the manufacturing processes from power perspectives as it is focusing only on the monitoring of the power grids using smart meters connected to SCADA systems. In this paper, a novel technique is proposed that is based on energy-aware manufacturing process control model using internet of things technology. The model is applied on cabling industry use case in addition to implementation of a MATLAB model for this purpose whereas the IoT physical layer is collecting, analyzing and communicating the electric power parameters correlated with the manufacturing process parameters received from PLC IoT nodes. Accordingly, the effective power quality is enhanced using manufacturing process control rather than additional correction nodes in traditional techniques. On applying the model on cabling use case, the Total Harmonic Distortion (THD-current) is improved 10 times to be 3.1% against 31.4% and the power factor is improved by 33% from 0.7 to 0.93 without additional correction nodes. © 2020 ASTES Publishers. All rights reserved
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.
Performance Improvement of npn Solar Cell Microstructure by TCAD Simulation: Role of Emitter Contact and ARC
(Multidisciplinary Digital Publishing Institute (MDPI), 2022-09) Marwa S, Salem; Zekry, Abdelhalim; Shaker, Ahmed; Abouelatta, Mohamed; Almurayziq, Tariq S; Alshammari, Mohammad T; El-Banna, Mohamed M
In the current study, the performance of the npn solar cell (SC) microstructure is improved by inspecting some modifications to provide possible paths for fabrication techniques of the structure. The npn microstructure is simulated by applying a process simulator by starting with a heavily doped p-type substrate which could be based on low-cost Si wafers. After etching deep notches through the substrate and forming the emitter by n-type diffusion, an aluminum layer is deposited to form the emitter electrode with about 0.1 µm thickness; thereby, the notches are partially filled. This nearly-open-notches microstructure, using thin metal instead of filling the notch completely with Al, gives an efficiency of 15.3%, which is higher than the conventional structure by 0.8%. Moreover, as antireflection coating (ARC) techniques play a crucial role in decreasing the front surface reflectivity, we apply different ARC schemes to inspect their influence on the optical performance. The influence of utilizing single layer (ZnO), double (Si3N4/ZnO), and triple (SiO2/Si3N/ZnO) ARC systems is investigated, and the simulation results are compared. The improvement in the structure performance because of the inclusion of ARC is evaluated by the relative change in the efficiency (∆η). In the single, double, and triple ARC, ∆η is found to be 12.5%, 15.4%, and 17%, respectively. All simulations are performed by using a full TCAD process and device simulators under AM1.5 illumination.
Performance Investigation of a Proposed Flipped npn Microstructure Silicon Solar Cell Using TCAD Simulation
(Multidisciplinary Digital Publishing Institute (MDPI), 2022-07) Salem, Marwa S; Zekry, Abdelhalim; Shaker, Ahmed; Abouelatta, Mohamed; ElBanna, Mohamed M; Almurayziq, Tariq S; Ramadan, Rabie A; Alshammari, Mohammad T
This work aims at inspecting the device operation and performance of a novel flipped npn microstructure solar cell based on low-cost heavily doped silicon wafers. The flipped structure was designed to eliminate the shadowing effect as applied in the conventional silicon-based interdigitated back-contact cell (IBC). Due to the disappearance of the shadowing impact, the optical performance and short-circuit current density of the structure have been improved. Accordingly, the cell power conversion efficiency (PCE) has been improved in comparison to the conventional npn solar cell microstructure. A detailed analysis of the flipped npn structure was carried out in which we per- formed TCAD simulations for the electrical and optical performance of the flipped cell. Additionally, a comparison between the presented flipped microstructure and the conventional npn solar cell was accomplished. The PCE of the conventional npn structure was found to be 14.5%, while it was about 15% for the flipped structure when using the same cell physical parameters. Furthermore, the surface recombination velocity and base bulk lifetime, which are the most important recombination parameters, were studied to investigate their influence on the flipped microstructure performance. An efficiency of up to 16% could be reached when some design parameters were properly fine-tuned. Moreover, the impact of the different physical models on the performance of the proposed cell was studied, and it was revealed that band gap narrowing effect was the most significant factor limiting the open-circuit voltage. All the simulations accomplished in this analysis were carried out using the SILVACO TCAD process and device simulators.
Performance Optimization of the InGaP/GaAs Dual-Junction Solar Cell Using SILVACO TCAD
(Hindawi, 2/19/2021) Salem, Marwa S.; Saif, Omar M.; Shaker, Ahmed; Abouelatta, Mohamed; Alzahrani, Abdullah J.; Alanazi, Adwan; Elsaid, M. K.; Ramadan, Rabie A.
Article Sections Research Article | Open Access Volume 2021 |Article ID 8842975 | https://doi.org/10.1155/2021/8842975 Marwa S. Salem, Omar M. Saif, Ahmed Shaker, Mohamed Abouelatta, Abdullah J. Alzahrani, Adwan Alanazi, M. K. Elsaid, Rabie A. Ramadan, "Performance Optimization of the InGaP/GaAs Dual-Junction Solar Cell Using SILVACO TCAD", International Journal of Photoenergy, vol. 2021, Article ID 8842975, 12 pages, 2021. https://doi.org/10.1155/2021/8842975 Hide citation Performance Optimization of the InGaP/GaAs Dual-Junction Solar Cell Using SILVACO TCAD Marwa S. Salem ,1,2 Omar M. Saif,3 Ahmed Shaker ,4 Mohamed Abouelatta ,5 Abdullah J. Alzahrani,1 Adwan Alanazi ,1 M. K. Elsaid,5 and Rabie A. Ramadan 1,6 1Department of Computer Engineering, College of Computer Science and Engineering, University of Ha’il, Ha’il, Saudi Arabia 2Department of Electrical Communication and Electronics Systems Engineering, Faculty of Engineering, Modern Science and Arts University (MSA), Cairo, Egypt 3Canadian International College, Engineering School, Giza, Egypt 4Engineering Physics and Mathematics Department, Faculty of Engineering, Ain Shams University, Cairo, Egypt 5Department of Electronics and Communications, Faculty of Engineering, Ain Shams University, Cairo, Egypt 6Department of Computer Engineering, Faculty of Engineering, Cairo University, Cairo, Egypt Show less Academic Editor: Elias Stathatos Published 19 Feb 2021 Abstract In this work, an optimization of the InGaP/GaAs dual-junction (DJ) solar cell performance is presented. Firstly, a design for the DJ solar cell based on the GaAs tunnel diode is provided. Secondly, the used device simulator is calibrated with recent experimental results of an InGaP/GaAs DJ solar cell. After that, the optimization of the DJ solar cell performance is carried out for two different materials of the top window layer, AlGaAs and AlGaInP. For AlGaAs, the optimization is carried out for the following: aluminum (Al) mole fraction, top window thickness, top base thickness, and bottom BSF doping and thickness. The electrical performance parameters of the optimized cell are extracted: , , , and the conversion efficiency () equals 36.71%. By using AlGaInP as a top cell window, the electrical performance parameters for the optimized cell are , , , and . So, AlGaInP is found to be the optimum material for the InGaP/GaAs DJ cell top window layer as it gives 4% higher conversion efficiency under 1 sun of the standard AM1.5G solar spectrum at 300 K in comparison with recent literature results. All optimization steps and simulation results are carried out using the SLVACO TCAD tool.
Role of Quasi-Fermi potential in modeling III-V TFETs: InAs as a case study
(Ain Shams University, 2022-10) Shaker, Ahmed; Sayed, Islam; Abouelatta, Mohamed; Fikry, Wael; Salem, Marwa; El-Banna, Mohamed
TFET accurate physically based models are highly required to analyze and predict the device character- istics for its future utilization in circuits. In order to precisely model TFETs, it is essential to understand the several aspects related to the physics-based modeling of these devices. Using 2D TCAD simulation, we showed that in order to appropriately model the electrostatic potential in InAs-based TFETs, the electron quasi-Fermi potential (eQFP) should be taken to depend on biasing conditions, both VDS and VGS, contrary to the case of Si-based TFETs in which the eQFP is considered independent of VGS which is widely encoun- tered in the literature. The study is carried out for InAs double-gate homojunction tunnel FETs (DG- TFETs). In addition, we applied the main key factor of dependence of eQFP on a modified TFET model and it is revealed that the interpretation of eQFP correctly predicts the electrostatic potential and the drain-to-source band to band tunneling current. 2022 THE AUTHORS. Published by Elsevier BV on behalf of Faculty of Engineering, Ain Shams Uni- versity. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/ by-nc-nd/4.0/).
Validation and Evaluation of a Behavioral Circuit Model of an Enhanced Electrostatic MEMS Converter
(Multidisciplinary Digital Publishing Institute (MDPI), 2022-06) Salem, Mona S; Zekry, Abdelhalim; Abouelatta, Mohamed; Shaker, Ahmed; Salem, Marwa S
In this current study, the validation and evaluation of a behavioral circuit model of electro- static MEMS converters are presented. The main objective of such a model is to accurately find the converter behavior through the proper choice of its circuit elements. In this regard, the model enables the implementation of the electrostatic MEMS converter using commercially available off-shelf circuit elements. Thus, the overall vibration energy harvesting system can be implemented and tested with- out the need for fabricating the converter. As a result, the converter performance can be verified and evaluated before its fabrication which saves the expenses of fabricating trailed prototypes. To test the model, we apply it to an enhanced converter in which the conventional electrostatic MEMS converter is modified by depositing the tantalum pentoxide, Ta2O5 , a high dielectric constant material, on its fingers’ sidewalls. Such a deposition technique causes an appreciable increase in the overall converter capacitance and, in turn, the output power, which is boosted from the range of µw to the range of mW. Next, the converter behavioral circuit model, which is based on representing its capacitances variations with respect to the input displacement, x caused by the vibration signal, C–x curve, is built up. The model is qualitatively validated and quantitatively evaluated. The enhanced converter performance is investigated through the interaction of its model with the power conditioning circuit. From the simulation results, it is revealed that the converter behavioral circuit model accurately accomplishes the vibration energy conversion operation. As a result, the specification of the required controlling pulses for the converter operation is accurately determined. Finally, the model accuracy is validated by calibrating its performance with a traditionally simulated and fabricated electrostatic MEMS converter.