This work aims at analyzing the effect of both Ag middle layer and annealing effects on the structural, optical and electrical properties of Al-doped ZnO (AZO) thin-films. In this framework, AZO/Ag/AZO tri-layers were deposited on glass substrates using RF magnetron sputtering technique. Structural, optical and electrical characterizations were carried out using XRD, UV-Vis Spectrophotometry and Hall measurements, respectively. The obtained XRD patterns demonstrated the enhanced crystallinity of the annealed AZO/Ag/AZO multilayer structure. In addition, transmittance spectra of prepared samples revealed the enhanced visible transparency of the annealed structure, showing a high average transparency of 85%. It is found also that the use of annealing and Ag middle layer can enlarge the band gap (3.53 eV). This is attributed to the increase of the free charge carrier, which can shift the Fermi Level. Electrical characterizations demonstrate that annealing process can modulate the electrical properties of the AZO/Ag/AZO thin-film, offering a high mobility of 17 cm 2 /Vs and a favorable sheet-resistance of 46 Ω/eq. Therefore, the present study can provide guidelines for the fabrication of alternative buffer layer, which can be appropriate for various thin-film solar cell technologies.

This work aims at analyzing the effect of combining Junctionless (JL) technology and gate-trench strategy for improving the electrical and switching performances of SiC power MOSFET devices. The device is modeled using numerical approaches to assess its performance for power electronic applications. It is found that the proposed device can allow achieving higher derived current capability and maintains low off-state current. In addition, the proposed gate-trench JL MOSFET demonstrates improved on-resistance and high breakdown characteristics, resulting in a superior Figure-of-Merit (FoM) value of BV 2 /Ron= 2580 MV/mΩ.cm -2 . To analyze the switching characteristics of the proposed transistor, the device is implemented in an inverter-gate circuit. It is shown that the analyzed power-MOSFET using combined JL and gate-trench aspects offers improved switching performances with low noise margin effects. Therefore, the proposed gate-trench JL MOSFET can address the trade-off between high breakdown characteristics and improved switching properties, suggesting it as a potential cost-effective alternative transistor for power electronics applications.

In a current study, we present an innovative model for optimization of hysteresis cycle parameters. Proposed model is applied to a steel sheet. In doing so, we have defined the interest of the use of Jiles-Atherton phenomenological model and we have specified our study on the case of the inverse model. The exploit of Particle Swarm Optimization technique was discussed with details. B(H) curves produced by modeling and experimentation are shown for the quasi-static frequency under sinusoidal magnetic excitation applied to a GNO Fe3%Si steel sheet. Simulation results are analyzed and compared with experimental obtained B(H) curve. In a first situation, a study was conducted after optimization, while in the second one; the specified investigation was carried out with optimization. The simulated and optimized B(H) curve and the experimental data show and confirm an excellent agreement. A highly successful performance has been made, validating our proposed Model.

This work aims at analyzing the effect of both Ag middle layer and annealing effects on the structural, optical and electrical properties of Al-doped ZnO (AZO) thin-films. In this framework, AZO/Ag/AZO tri-layers were deposited on glass substrates using RF magnetron sputtering technique. Structural, optical and electrical characterizations were carried out using XRD, UV-Vis Spectrophotometry and Hall measurements, respectively. The obtained XRD patterns demonstrated the enhanced crystallinity of the annealed AZO/Ag/AZO multilayer structure. In addition, transmittance spectra of prepared samples revealed the enhanced visible transparency of the annealed structure, showing a high average transparency of 85%. It is found also that the use of annealing and Ag middle layer can enlarge the band gap (3.53 eV). This is attributed to the increase of the free charge carrier, which can shift the Fermi Level. Electrical characterizations demonstrate that annealing process can modulate the electrical properties of the AZO/Ag/AZO thin-film, offering a high mobility of 17 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> /Vs and a favorable sheet-resistance of 46 Ω/eq. Therefore, the present study can provide guidelines for the fabrication of alternative buffer layer, which can be appropriate for various thin-film solar cell technologies.

In this paper, TCO (Transparent Conductive Oxide) incorporating ultrathin Ag intermediate film is proposed as a new buffer layer to enhance the efficiency of CIGS thin-film solar cells (TFSCs). In this regard, versatile multilayer thin-films based on ZnO/Ag/ZnO and ITO/Ag/ITO structures were deposited on glass using RF magnetron sputtering technique to determine the optoelectronic parameters of the multilayer structures. The elaborated samples were then characterized using SEM, EDS, XRD, and UV-Visible absorption spectroscopy techniques to investigate the structure morphological, optical, and electronic properties. The deposited multilayer thin-films showed amorphous-like structure and exhibited a broadband absorbance over the visible and even NIR spectrum ranges, indicating its potential application as alternative buffer layers for thin-film solar cells. In this context, TCO/Ag/TCO/CIGS solar cells have been numerically investigated using the deposited multilayer optoelectronic properties. It was revealed that the estimated efficiency of the ZnO/Ag/ZnO/CIGS-based solar cell could reach 18.5% with an open circuit voltage of 0.7 V and a short-circuit current density of 34.8 mA/cm(2). The performances exhibited by the investigated solar cell demonstrated that ZnO/Ag/ZnO multilayer can be used as an alternative to the conventional CdS buffer layer for developing high-performance non-toxic CIGS solar cells.

In this work, the experimental analysis of the impact of annealing on the structural and optical performances of SiC/Ag/SiC thin-film multilayer structure deposited by RF sputtering technique has been performed. A comprehensive investigation of the developed heterostructure by analyzing the optical and structural characteristics was carried out using appropriate experimental facilities such as X-Ray Diffraction (XRD) and UV-Vis spectra measurements, in order to assess the optical and structural performances including the effects of annealing process. It was demonstrated that the annealing treatment paves a path toward developing high-performance visible-blind UV sensors, where the annealed structure exhibited a superior light-rejection ratio in comparison with that of the unannealed counterpart. Moreover, XRD structural measurements revealed the absence of peaks corresponding to the SiC bottom and top layers, confirming the amorphous state of the sputtered unannealed and annealed multilayer structures. Therefore, this work may help clarify the roles of annealing process in improving the properties of SiC/Ag/SiC multilayer structure to develop high-performance thin-films for CMOS-based optoelectronics and photovoltaic applications.

The purpose of the present work is to experimentally investigate a new high-performance broadband photodetector (PD) based on all-amorphous ZnO/Si heterostructure incorporating Ag ultrathin films. The sensor was developed using the RF magnetron sputtering method at room temperature conditions. In this context, a-ZnO/ Ag/a-ZnO/a-Si/Ag/a-Si embedded ultrathin-films were sputtered on the glass substrate. The device structural, morphological, optical, and photodetection characteristics were studied by performing XRD, SEM, EDX, UV-Vis-NIR spectroscopy, and photoresponse characterizations. The analysis showed an improved absorbance behavior over a wide spectral range. It was demonstrated that the use of a-ZnO/a-Si heterostructure with Ag intermediate ultrathin-films incorporation leads to achieving multiband photodetection property with low dark noise effects, where the photodetector provides high responsivity values of 208 mA/W, 160 mA/W, and 180 mA/ W over UV, Visible and NIR spectral ranges. These improvements are attributed to the combined effects of improved light-scattering due to the effect of agglomeration of silver on the surface, and the absorbance improvement enabled by optical micro-cavity effects generated by the inserted Ag ultrathin-films. Therefore, the present experimental study can offer new strategies for the development of highly-detective broadband multi spectral photosensors based on a-Si photonics platform, which are suitable for optoelectronic applications.

In this paper, the combination of ZnO top layer and intermediate Ag ultrathin films is proposed to enhance the performance of Amorphous-Silicon (a-Si) Schottky Barrier Diodes (SBDs). The latter was fabricated by means of RF magnetron sputtering technique. Accordingly, ZnO/Ag/ZnO/a-Si/Ag/a-Si embedded thin-films were sputtered at room temperature conditions on glass substrate. The morphological and structural properties of the prepared structure were analyzed by performing XRD and SEM characterizations. Characterizations showed an amorphous-like structure of the prepared samples. The electrical parameters of a-Si SBDs with and without Ag middle layer were extracted from current-voltage measurements. It was revealed that the use of ZnO top layer combined with Ag ultrathin-films leads to enhance the electrical behavior of a-Si SBD, where the device offers low series resistance of $2\times 10^{3}\ \Omega$ and high derived current capability, while maintaining low off current. This improvement is attributed to the enhanced resistive behavior due to the presence of Ag thin-films. Therefore, the present investigation can provide new strategies for the elaboration of highly-performance SBDs based on a-Si platform, which are suitable for the emerging optoelectronic applications.

This work aims at investigating the structural and electrical characteristics of Al-doped ZnO (AZO) ultrathin-layers. In this context, the latter were developed on glass substrates by means of RF magnetron sputtering at room temperature conditions. The influence of RF sputtering power on the film electrical and structural characteristics was analyzed by carrying Hall measurements and XRD experimental characterizations. The obtained XRD spectra revealed the amorphous state of the developed AZO thin─layers, which is related to their ultralow thickness. In addition, electrical characterization demonstrated the ability of the RF sputtering power for modulating the film electrical behavior. It was found that the lowest sheet resistance and highest carrier mobility (55 cm 2 /Vs) could be achieved by using a low RF power value of 60 W. thus, the presented investigation can be effective for the preparation of efficient Al-doped ZnO ultrathin-films effective for optoelectronic and photovoltaic devices.

In the present study, (NiO)-niobium (Nb)/ niobium oxide (NbO)- nickel (Ni) bilayer structure was prepared by using Radio Frequency (RF) magnetron sputtering technique. The sub-layers were deposited successively on glass substrate. The magnetic properties of the prepared samples were carried out at room temperature in both perpendicular and parallel magnetic field to the sample. The Preisach model was used to fit the magnetic behavior of the developed NiO-Nb/NbO-Ni bilayer thin films. XRD measurements were performed to assess the structural properties of the elaborated thin-films. It is found that the obtained results correlates well with the experimental ones, were a good agreement between the experimental data and the theoretical modeling is recorded. Therefore, the obtained results indicate the effectiveness of the proposed methodology based on experiments assisted by accurate modeling approaches and provides a sound pathway for developing potential alternative materials for sensing and spintronics applications.

In this paper, a new high-performance tunable band-selective (UV-Visible) photodetector (PD) based on RF sputtered a-SiC active layer is demonstrated. SiC thin-films were deposited on glass substrate by RF magnetron sputtering method at different sputter power values ranging from 60 W to 120 W. The samples morphological, structural, optical and photodetection properties were investigated by carrying out XRD, SEM, EDS, UV-Vis spectroscopy and photoresponse measurements. It was revealed that the sputtering power could modulate the optical behavior of a-SiC alloy, tuning favorable visible absorbance at high sputter power. This phenomenon is correlated with the influence of the RF power on the SiC film structural properties and compositions. Interestingly, measurements showed that a-SiC PD elaborated at 60 W of RF power can detect UV radiation with a high responsivity of 138 mA/W, low noise effects, superior detectivity of 7.8 x 1012 Jones, while maintaining the visible blindness property. On the other hand, the prepared device at high sputtering power exhibits extended photoresponse characteristics, yielding 426 mA/W and 77 mA/ W of responsivity values over UV and visible ranges, respectively. Therefore, the present investigation can provide a new strategy for the design and fabrication of photodetector devices based on SiC platform with broadband and solar-blind adjustable sensing purposes according to the desired application. (c) 2022 Elsevier B.V. All rights reserved.

In this study, metal-semiconductor-metal (MSM) ultraviolet (UV) photodetector (PD) structure based on amorphous-silicon Carbide (a-SiC) was developed by RF sputtering deposition. $\text{ZnO}$ thin-film behaving like as passivation and efficient UV absorber layer was sputtered on the a-SiC film forming a heterostructured device. A comprehensive study of the device structural and optical performances is performed by XRD and UV-Vis spectra measurements. Significantly, the fabricated device exhibits an excellent ultraviolet absorption ability (85%). Moreover, the elaborated MSM UV-PD reveals a good responsivity of 37 $\text{mA}/\mathrm{W}$ , an extremely reduced dark current of 10 $\text{pA}$ and high $\mathrm{I}_{\mathrm{o}\mathrm{N}}/\mathrm{I}_{\mathrm{o}\mathrm{F}\mathrm{E}}$ ratio of 120 $\text{dB}$ at self-powered mode. These improved performances can be explained by the effect of the heterostructure nature of the developed ZnO/a-SiC, which leads to enhance photo-induced carrier generation mechanism and also transport of carriers. The obtained results suggest that the fabricated amorphous UV MSM PD herein show a cost-effective approach for developing novel self-powered UV photosensors potentially appropriate for high temperature and power applications.

In this paper, Graded Band-Gap (GBG) amorphous-silicon Carbide (a-SiC) thin-film was successfully fabricated using RF magnetron technique on glass substrate. Accordingly, a-SiC ultrathin layers were sputtered at dissimilar RF power values. XRD and Spectrophotometry measurements were performed to assess the structural, optical and electronic properties of the prepared a-SiC samples. It was found that all samples exhibit an amorphous state. Besides, characterizations showed that the a-SiC band gap can be tuned by using dissimilar RF power values during the sputtering process. In this context, GBG a-SiC film is elaborated by a sequential sputtering process at various RF power values ranging from 60 W to 120 W. It was revealed that the optical band gap is reduced from 2.54 eV to 1.9 eV for the RF power values of 60 W and 120 W, respectively. This is mainly attributed to the effect of the Si and C content on the electronic behavior of the SiC alloy, where the variation of the RF power can induce significant changes regarding the Si/C ratio of the SiC sample. These significant results suggest the elaboration of GBG a-SiC, which can be highly suitable for various applications including photovoltaic and optoelectronic devices.

In this work, an experimental investigation of the impact of the thickness parameter on the magnetic, structural and hysteresis cycle characteristics of thin Ni-based (Ni/NiO) multi-layers was carried out. The multilayer structure has been deposited using RF sputtering technique at room temperature. A comprehensive study of the deposited structure was performed by analyzing the structural and hysteresis cycle characteristics via appropriate experimental facilities such as X-Ray Diffraction (XRD) and magnetometer (VSM) platform, in order to plot the experimental cycles of hysteresis properties as a function of temperature and the thickness of the multilayer structure.

In this paper, the optimization, elaboration and characterization of an efficient spectral beam splitter based on a simple RF sputtered ITO/Ag/ITO (IAI) ultra-thin multilayer structure are presented. An experimental investigation assisted by Genetic Algorithm (GA) metaheuristic optimization was carried out to achieve high-performance spectral splitter for tandem solar cell applications. The RF magnetron sputtering method was used to elaborate the optimized IAI structure. The optical and structural properties of the sputtered splitter were also analyzed using UV-Vis-IR spectroscopy and X-ray diffraction (XRD) measurements. It is found that the elaborated splitter structure offers 84% of transparency and a high reflectance of 87% with an optimum cut-off wavelength of 800 nm. This is attributed to the design approach, which leads to promote spectral splitting mechanism by inducing efficient optical modulation. Interestingly, a new Figure of Merit (FoM) parameter, which evaluates the optical splitting performances is proposed. Moreover, a new Perovskite/InGaAs tandem cell is proposed and analyzed to show the impact of the elaborated spectrum splitter on the solar cell efficiency. It is revealed that the investigated solar cell exhibits an improved efficiency approaching 30%. The latter value far surpasses that provided by Perovskite tandem cells. These results indicate that our spectrum splitting approach can open a new pathway towards designing high-performance tandem photovoltaic devices.

High-performance multispectral photodetectors (PDs) are highly attractive for the emerging optoelectronic applications. In this work, a new broadband PD based on p-NiO/Ag/n-ITO heterostructure was fabricated by RF magnetron sputtering technique at room temperature. The tri-layered structure offering multispectral detection property was first identified using theoretical calculations based on combined FDTD and Particle Swarm Optimization (PSO) techniques. The crystal structure of the elaborated sensor was analyzed using X-ray diffraction (XRD) method. The device optical properties were investigated by UV-Vis-NIR spectroscopy. The NiO/Ag/ITO heterostructured PD shows a high average absorbance of 63% over a wide spectrum range of [200 nm-1100nm]. Compared with NiO and ITO thin-films, the performances of the heterostructured device are considerably enhanced. It was found that the prepared PD with NiO/Ag/ITO heterostructure merges the benefits of multispectral photodetection with reduced optical losses and efficient transfer of photo-induced carrier. The device demonstrated a high I-ON/I-OFF ratio of 78 dB and an enhanced responsivity under UV, visible and NIR lights (171 mA/W at 365 nm, 67 mA/W at 550 nm and 93 mA/W at 850 nm). The broadband photodetection property enabled by the optimized NiO/Ag/ITO heterostructure opens a new route for the elaboration of low-cost devices that can offer multiple sensing purposes, which are highly suitable for optoelectronic applications.

Cost-effective multispectral photodetectors (PDs) exhibiting a high UV-Visible-NIR photoresponse offer an avenue for developing environmental monitoring devices, imaging sensors, object discrimination, and optical links. However, PDs based on a single semiconductor as light-sensitive layer are unable to provide broadband photodetection properties. In this work, a new PD device based on ZnO-ZnS Microstructured Composite (MC) which achieves a high UV-Visible-NIR photoresponse is demonstrated. The ZnO-ZnS MC is elaborated by combining vacuum thermal evaporation technique and a suitable annealing process. Scanning Electron Microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and UV-VisNIR spectroscopy were used to elucidate the morphological, structural and optical properties of the prepared sample. It was demonstrated that the ZnO-ZnS MC can be useful to enhance the visible absorbance efficiency by promoting efficient light-scattering effects. It is revealed that the prepared UV-Vis-NIR PD offers a low dark current of 5 nA, a high I-ON/I-OFF ratio of 78 dB and an enhanced responsivity in UV, visible and NIR ranges. The proposed multispectral PD demonstrates a high I-ON/I-OFF current ratio under self-powered working regime. Therefore, the proposed ZnO-ZnS MC is believed to provide new insights in developing efficient, self-powered and low-cost multispectral PDs for high-performance optoelectronic systems. (C) 2020 Elsevier B.V. All rights reserved.

In this paper, ZnO-ZnS composite structure is proposed as a new efficient and earth-abundant absorber material for thin-film solar cells (TFSCs). Promising elaboration strategy based on combining vacuum thermal evaporation technique and oxidation process under an annealing temperature of 500 ?C was used to prepare ZnO-ZnS composite with high sun-light absorption capabilities. The fabricated microstructure was then characterized by Scanning Electron Microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and UV?Visible absorption spectroscopy. The influence of the annealing time on the structural and optical performances of the prepared samples was investigated. Surface analysis demonstrated the ZnO decoration of ZnS thinfilm, where SEM images showed dense and pinhole-free ZnO-ZnS composite with micrometer-sized grains and a few voids visible at thin-films surface. Optical characterization showed that the prepared thin-film absorber exhibits an optical band-gap of 2.65 eV with a high Total Absorption Efficiency (TAE) of 62% and an absorption coefficient exceeding 2 ? 104 cm- 1. In addition, I-V characteristics under dark and 1-sun illumination of the microstructured ZnO-ZnS composite were extracted. It was revealed that the proposed absorber showcases a high visible photoresponse. Therefore, promoting effective light-scattering effects, this innovative ZnO-ZnS composite offers a sound pathway to prepare alternative low-cost absorbers for the future development of TFSCs.

The rapid progress of wide band gap SiC semiconductor material opens up new opportunities to develop efficient monolithically integrated ultraviolet (UV) photonic and power systems for a wide range of advanced applications. In this paper, low-noise solar-blind UV photodetector (PD) based on all-amorphous ZnO/SiC heterostructure was fabricated via RF magnetron sputtering technique. The device structural and optical properties were investigated before and after thermal treatment at different annealing temperature values varying from 300 degrees C to 600 degrees C. UV-Visible spectroscopy revealed that the annealing process has a beneficial effect in terms of high UV absorbance and solar-blindness properties. Photoelectrical characterization demonstrated the high UV photoresponse and low dark noise of the prepared UV PD based on all-amorphous ZnO/SiC structure. Improvement of the device performances were achieved by an appropriate annealing process. After post-annealing, the thermally treated ZnO/SiC UV PD at 500 degrees C exhibits a high detectivity of 2.4 x 10(12) Jones, high signal to noise ratio of 2.64x10(5) and a giant UV-Vis rejection ratio of 5.9 x 10(3). Therefore, the present study may provide new perspectives for fabricating ultralow dark noise solar-blind UV PD based on all-amorphous ZnO/SiC heterostructure, which promotes the development of integrated UV photonic systems based on SiC platform.

In this paper, the role of introducing Germanium (Ge)/IGZO heterostructure in enhancing the Infrared (IR) photodetection properties of thin-film phototransistor (Photo- TFT) is presented. Numerical models for the investigated device are developed using ATLAS device simulator. The influence of Ge photosensitive layer thickness on the sensor IR photoresponse is carried out. It is revealed that the o...