Fayçal Meddour

Bio: Fayçal Meddour is an academic researcher from University of Batna. The author has contributed to research in topics: Materials science & Solar cell. The author has an hindex of 4, co-authored 15 publications receiving 43 citations.

Performance enhancement of (FAPbI3)1-x(MAPbBr3)x perovskite solar cell with an optimized design

Abstract: In this paper, an optimized design of (FAPbI3)1-x(MAPbBr3)x perovskite solar cell is numerically investigated using SCAPS-1D software package. A variety of potential charge transport materials are investigated. Cu2O as HTL and ZnO as ETL outperform other choices; they are therefore considered as the best candidates. The impact of the electronic properties of both ZnO/perovskite and Perovskite/Cu2O interfaces on the solar cell performance is thoroughly investigated. We discovered that appropriate values of the conduction band offset (CBO+ = 0.29) and valence band offset (VBO+ = 0.09) assure a “spike-type” band alignment at both interfaces. This choice lowers the unwanted interfacial recombination mechanism, resulting in a challenging PCE. In addition, the impact of the work function of back contact is also investigated. According to simulation findings, Ni back electrodes with a work function of 5.04 eV is appropriate for Zn0.8Mg0.2O/(FAPbI3)0.85(MAPbB3)0.15/Cu2O perovskite solar cell. The optimized FTO/MgZnO/(FAPbI3)0.85(MAPbBr3)0.15/Cu2O/Ni PSC reaches a conversion efficiency as high as 25.86%. These findings will pave the way for the design of low-cost, high-efficiency solar cells.

An efficient small size electromagnetic energy harvesting sensor for low-DC-power applications

Abstract: An efficient small size electromagnetic energy harvesting sensor for low-DC-power applications is proposed. The sensor consists of two main parts: a dual polarisation square patch antenna used to collect the RF energy at a central frequency of 2.45 GHz, and two voltage doublers rectifier circuit for the RF-to-DC conversion. The overall size of the design is 50 × 50 × 6.2 mm3. Firstly, the antenna is designed using high-frequency structure simulator software; followed by the design of the rectifier circuit in advanced design system. After simulations, a sensor prototype is fabricated using F4B as the antenna substrate. Measurements show that the sensor achieves a comparatively high maximum measured efficiency of 41% for a power level of −10 dBm. The sensor has a simple structure, it is compact sized, light weight, and presents a high RF-to-DC conversion efficiency for low-RF-power levels which can be used to charge different low-DC-power devices.

Significant improvement of infrared graphene nanoribbon phototransistor performance: A quantum simulation study

Abstract: In this paper, we investigate an optimized design of textured graphene nanoribbon phototransistor via quantum simulations. The graphene layer with textured morphology performs dual role, notably as the carrier conduction channel and also as an absorber of light. The proposed design characteristics are numerically investigated via a non-equilibrium Green’s function (NEGF) mode-space formulism in the ballistic edge. The method suggested was tailored to the modern carrier transport model, Electron-photon and Electron-phonon interactions. Besides, a simple analytical model that considers graphene light trapping morphology is developed and introduced into the simulation. This model is regarded as a fitness function for Multi-Objective Genetic Algorithm (MOGA) optimization technique to improve the GNR phototransistor sensing capability. Simulations results show that, compared to a conventional phototransistor, the proposed design has higher responsivity (47.55 mA/W), good sensitivity (2.41 × 103), higher detectivity (6.09 × 1010 Jones), better Photocurrent to Dark Current Ratio (PDCR) (24.15) and keeping better scaling capability.

Modeling of a smart humidity sensor

Abstract: This work aims to achieve a design of a smart humidity sensor, the goal of this study is to eliminate the non-linearity and the cross sensitivity of the output sensor used The humidity sensor is a MEMS capacitive kind Using neuronal networks and Matlab environment we have done the training to design an analytical model ANN and create a model for this component in the PSPICE simulator library, where the output of this model is identical to the output of the MEMS humidity sensor used Because our sensor is a capacitive type, the obtained model on PSPICE reflects the humidity variation by a capacity variation, which is a passive magnitude; it requires a conversion to an active magnitude, why we realize a conversion capacity/voltage using a switched capacitor circuit SCC A linearization, by a Matlab program, is applied to ANN response whose goal is to create a database for an element of correction, can correct its nonlinear response The training for the new database provides us with the inverse model INV-ANN The three blocks; ANN model, model reverse INV-ANN and the capacity/voltage converter, represent the smart sensor

Nuclear Instruments and Methods in Physics Research A

Abstract: A novel prism has been devised which can be used in place of the ‘flag’ in an optical shadow-sensing type of displacement sensor, for example. In this way, theoretically the displacement sensitivity of the sensor can be doubled. Such a prism has been manufactured, and its displacement-doubling property has been verified.

Investigations on the sensing mechanism of humidity sensors based on electrospun polymer nanofibers

Abstract: Humidity sensing mechanism of sensors based on electrospun polyaniline (PANI) nanofibers was investigated. Dynamic adsorption and desorption behavior of the PANI nanofibers under different humidity levels were monitored by quartz crystal microbalance measurements and compared with their impedance response. It was found that the nanofiber sensor exhibited fast, reversible and highly sensitive impedance change as a function of water molecules adsorbed. Nyquist plots and Bode plots of the nanofiber humidity sensor under different humidity levels were obtained by electrochemical impedance spectra measurements at room temperature. An electrical equivalent circuit was established to model the impedance response to humidity variation of the nanofiber sensor. Calculated results using the model fitted quite well with the measured spectra. Exploration of the sensing mechanism was attempted by correlating the variation with humidity of three components of the equivalent circuit to the morphology of the electrospun nanofiber sensors.

Effect of Various Electron and Hole Transport Layers on the Performance of CsPbI3-Based Perovskite Solar Cells: A Numerical Investigation in DFT, SCAPS-1D, and wxAMPS Frameworks

Abstract: CsPbI3 has recently received tremendous attention as a possible absorber of perovskite solar cells (PSCs). However, CsPbI3-based PSCs have yet to achieve the high performance of the hybrid PSCs. In this work, we performed a density functional theory (DFT) study using the Cambridge Serial Total Energy Package (CASTEP) code for the cubic CsPbI3 absorber to compare and evaluate its structural, electronic, and optical properties. The calculated electronic band gap (Eg) using the GGA-PBE approach of CASTEP was 1.483 eV for this CsPbI3 absorber. Moreover, the computed density of states (DOS) exhibited the dominant contribution from the Pb-5d orbital, and most charges also accumulated for the Pb atom as seen from the electronic charge density map. Fermi surface calculation showed multiband character, and optical properties were computed to investigate the optical response of CsPbI3. Furthermore, we used IGZO, SnO2, WS2, CeO2, PCBM, TiO2, ZnO, and C60 as the electron transport layers (ETLs) and Cu2O, CuSCN, CuSbS2, Spiro-MeOTAD, V2O5, CBTS, CFTS, P3HT, PEDOT:PSS, NiO, CuO, and CuI as the hole transport layers (HTLs) to identify the best HTL/CsPbI3/ETL combinations using the SCAPS-1D solar cell simulation software. Among 96 device structures, the best-optimized device structure, ITO/TiO2/CsPbI3/CBTS/Au, was identified, which exhibited an efficiency of 17.9%. The effect of the absorber and ETL thickness, series resistance, shunt resistance, and operating temperature was also evaluated for the six best devices along with their corresponding generation rate, recombination rate, capacitance–voltage, current density–voltage, and quantum efficiency characteristics. The obtained results from SCAPS-1D were also compared with wxAMPS simulation results.