The numerical simulation tool SCAPS-1D was used to analyze perovskite solar cell having the architecture ITO/ PEDOT:PSS or GO /CH3NH3PbI3-xClx/ PCBM /Au contains inverted planar hetero-junction device. In this work, we investigated the effect of inserting the Graphene Oxide (GO) as Hole Transport layer (HTL) on the performance of perovskite solar cells. Simulation results show that the use of GO as a hole transport layer is efficient. The efficiency of PSCs based on GO HTL was increased by about 1.6 % compared to the conventional PEDOT:PSS HTL device. The obtained results of optimizing the thickness of GO HTL exhibited an optimum value around 10 nm with an efficiency of 12.35 %, Voc of 1.19 V and FF of 54.8 %. We have also shown that the performance of device for high GO carrier density is a better than with low ones. In addition, increasing the temperature beyond the optimum value obtained around 320 K for both HTL materials (GO and PEDOT:PSS) has detrimental effect on the performance of the perovskite solar cells however the device is more sensitive to the temperature with PEDOT:PSS than the GO ones. The effect of band gap of GO on the performance of device is also studied. The obtained results underline the determining role playedby this parameter with an optimum value around 3.25 eV.

Phosphorus nickel alloy, intended for anticorrosion coating, was prepared and deposited at room temperature on copper substrate by chronoamperometry technique in a sulphate bath. The effect of potential on the chemical composition, nucleation and growth, the structure and surface morphology during the electrodeposition of this alloy was presented in this work. X-ray microanalysis showed that the content of phosphorus in the prepared alloys decreases with increasing cathodic potential. Chronoamperograms analysis indicated that the nucleation process is instantaneous and of three-dimensional (3D) growth and is controlled by kinetics. X-ray diffraction analysis revealed an amorphous structure while SEM images showed a smooth appearance with pore presence.

In this paper, a new heterojunction structure based on ultrathin-film ITO sputtered on non-hydrogenated amorphous-silicon (a-Si) is developed for high-detectivity solar-blind UV-photodetector (UV-PD) based on silicon (Si) photonics technology. A strategic combination of Particle Swarm Optimization (PSO) and numerical analysis is used to find out the best design offering superior optoelectronic performance. The optimized design is then elaborated using RF magnetron sputtering technique. A comprehensive investigation of the device structural and optoelectronic properties was carried out, incorporating the influence of heat treatment at temperature values ranging from 300°C to 600°C. X-Ray Diffraction (XRD) measurements indicate that the crystallinity of the sputtered layers was enhanced by increasing the annealing temperature. Significantly, photoelectrical characterization showed that the annealed ITO/a-Si UV-PD exhibits high detectivity exceeding 10¹³ Jones with a highly improved UV-to-Vis rejection ratio of 5.7 × 10³. The ITO/a-Si heterojunction generated a built-in potential, enabling effective separation and transport of photo-induced carriers, thereby reducing recombination losses. Therefore, by well optimizing the proposed heterostructure and the annealing conditions, we were able to elaborate new highly detective, thin-film solar-blind UV-PD based on Si-photonics platform, which can be a promising alternative for future high-performance and cost-effective optoelectronic systems.

In this paper, a new heterojunction structure based on ultrathin-film ITO sputtered on non-hydrogenated amorphous-silicon (a-Si) is developed for high-detectivity solar-blind UV-photodetector (UV-PD) based on silicon (Si) photonics technology. A strategic combination of Particle Swarm Optimization (PSO) and numerical analysis is used to find out the best design offering superior optoelectronic performance. The optimized design is then elaborated using RF magnetron sputtering technique. A comprehensive investigation of the device structural and optoelectronic properties was carried out, incorporating the influence of heat treatment at temperature values ranging from 300°C to 600°C. X-Ray Diffraction (XRD) measurements indicate that the crystallinity of the sputtered layers was enhanced by increasing the annealing temperature. Significantly, photoelectrical characterization showed that the annealed ITO/a-Si UV-PD exhibits high detectivity exceeding 10¹³ Jones with a highly improved UV-to-Vis rejection ratio of 5.7 × 10³. The ITO/a-Si heterojunction generated a built-in potential, enabling effective separation and transport of photo-induced carriers, thereby reducing recombination losses. Therefore, by well optimizing the proposed heterostructure and the annealing conditions, we were able to elaborate new highly detective, thin-film solar-blind UV-PD based on Si-photonics platform, which can be a promising alternative for future high-performance and cost-effective optoelectronic systems.

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.

In this work, a new Ultraviolet Optically Controlled Graphene Field-Effect Transistor (UV-OC-GFET) based on Graded Band-Gap (GBG) ZnMgO photosensitive-gate is proposed. The device drain current model is numerically developed by self-consistently solving the Schrödinger/Poisson equations based on non-equilibrium Green's function (NEGF) formalism. The influence of GBG strategy with different profiles on the device sensing performances is analyzed. Our investigation reveals that the use of both GBG ZnMgO photo-gate and graphene nanoribbon channel offers the dual-benefit of improved electric field distribution in the photosensitive layer and enhanced drain current. This leads to outperforming the device Figure of Merits (FoMs). In this context, it is found that the proposed UV sensor with optimized band-gap profile exhibits giant responsivity exceeding 1.5 × 10⁶ A/W with superb detectivity of 7 × 10¹⁴ Jones, far surpassing that of the conventional Si-channel based phototransistors. Therefore, this innovative strategy based on graphene nanoribbon channel combined with GBG sensitive-gate pinpoints a new path towards achieving high-performance visible-blind UV-phototransistor, making it a potential alternative photoreceiver for chip-level optical communication and optoelectronic applications.

In this paper, embedded amorphous-silicon (a-Si) and titanium (Ti) ultrathin-films forming a multilayer structure is proposed as a new efficient absorber material for thin-film solar cells (TFSCs). Promising design strategy based on combining FDTD (finite difference time domain) with particle swarm optimization (PSO) was adopted to identify the a-Si/Ti multilayer structure offering the highest total absorbance efficiency (TAE). It is found that the proposed multilayer structure can serve as an effective absorber, yielding superb TAE exceeding 80%. The a-Si/Ti multilayer was then elaborated by successive growth of a-Si and Ti ultrathin layers using RF magnetron sputtering technique. The sputtered a-Si/Ti thin-film was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and UV–visible absorption spectroscopy. Measurements showed a unique optical behavior, promoting broadband absorbance over the visible and even NIR spectrum ranges. In particular, the prepared a-Si/Ti absorber exhibits an optical band-gap of 1.36 eV, which is suitable for photovoltaic applications. A performance assessment of the elaborated absorber was investigated by extracting I-V characteristics and electrical parameters under dark and 1-sun illumination. It is revealed that the proposed absorber demonstrates outstanding electrical and sensing performances. Therefore, promoting enhanced resistive behavior and light-scattering effects, this innovative concept of optimized a-Si/Ti multilayer provides a sound pathway for designing promising alternative absorbers for the future development of a-Si-based 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 °C to 600 °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 °C exhibits a high detectivity of 2.4 × 10¹² Jones, high signal to noise ratio of 2.64×10⁵ and a giant UV–Vis rejection ratio of 5.9 × 10³. 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.

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-Vis-NIR 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.

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 thin-film, 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.

Laser communication between satellites in the constellation and from the satellites to ground stations offers a gigantic data rate for the users. This principal advantage drives telecom companies to develop this technology to use it like a carrier signal, the most disadvantage of this technology is the need to very complicated pointing systems between the transmitter and the receiver due to a very small beam divergence, continually moving of satellites in orbits and the distance between the satellites (tens of thousands of kilometers). The laser beam suffers continuously from several factors like atmospheric turbulences, internal and external vibrations. All these factors lead to an increase in the bit errors rate and cause degradation in the communication quality. This paper deals with a new method of modelisation of external effects in transmission of signal light from a ground station to the satellite through atmospheric disturbances. Indeed, an in-depth investigation, of the influences of satellite vibrationsinlaser signal transmission between satellites constellation, has been conducted by studying the effect of the intensity of vibrations on the optical signal amplitude. Some solutions are proposed to improve the efficiency of optical satellites communications.

To boosting the performance of inverted p-i-n-type planar hetero-junction architecture photovoltaic cells based on CH₃NH₃PbI₃ perovskite materials, a thin buffer layer Bathocuproine (BCP) is introduced between the Electron Transporting Layer (ETL) PCBM and the metal contact. The trends in parameters Perovskite Solar Cells (PSCs) inserting BCP is studied using solar cell capacitance simulator (SCAPS-1D). The obtained results of optimizing the thickness of the Bathocuproine (BCP) buffer layer exhibited optimum value at 5 nm, with power conversion efficiency (PCE) of 17.30 %, V_OC of 1.39 V, and FF of 62.89 %. The carrier concentration was higher than 10¹⁷ cm^-3 increases sharply the conversion efficiency by about 0.35-2.3 %. Further, the lower metal work function (Ф_m<4.3 eV) enhances the electrical parameters where the efficiency up to 21.3 %.

Zinc Oxide (ZnO) and Nickel Oxide (NiO) thin films were prepared using the spray pyrolysis technique using three different quantities of solution 5, 10, and 15 ml, to modify their optical properties. Optical characterization of the obtained thin films showed that the bandgap and the transparency of NiO and ZnO decrease with increasing solution quantity. The films are highly transparent making them suitable for optoelectronic applications. It is worth noting that NiO has a low growth rate compared to ZnO due to its larger bandgap. The different parameters obtained for both films are then used to simulate the electrical characteristics and the responsivity of a NiO/ZnO heterojunction based PN photodiode. Both the electrical characteristics and the responsivity improve with increasing quantities of solution. These findings may help to find an optimal design for photodiode fabrication.

In this paper, novel self-powered, solar-blind UV photodetector (PD) designs based on a ZnO thin-film with engineered back metal layer (BML) were fabricated by RF magnetron sputtering and e-beam evaporation techniques. An exhaustive study concerning the impact of dissimilar BML (Au and Ni) on the device structural, optical and electrical properties was carried out. The measured I–V curves illustrated an asymmetrical behavior, enabling a clear and distinctive photovoltaic mode. Superb sensitivity of 10⁷, high I_ON/I_OFF ratio of 149dB, ultralow dark-noise current less than 11pA and responsivity exceeding 0.27A/W were reached for the prepared ZnO-based UV-PDs in self-powered mode. The role of the engineered BML in promoting effective separation and transfer of the photo-induced carriers was discussed using the band-diagram theory. The influence of the annealing process on the UV-sensor performance was also investigated. The annealed device at 500°C demonstrated a lower dark current of a few picoamperes and a high rejection ratio of 2.2×10³, emphasizing its exciting visible blindness characteristics. Therefore, the use of an engineered BML with optimized annealing conditions open up new perspectives to realizing high-performance, self-powered solar-blind UV-PDs based on simple thin-film-ZnO structure strongly desirable for various optoelectronic applications.

The mechanical behavior of few-layered borophene (η-LB), at different temperatures ranging from 10 to 800 K in conjunction with a variant strain-rate, is studied by employing molecular dynamics simulations based on the Stillinger-Weber potential. The uniaxial tensile deformations along the zigzag- and armchair-direction of the hexagonal lattice are considered for η-LB, with η = 1, 2, 3, 4. We find an extremely anisotropic mechanical response. Parameters such as Young’s modulus and fracture strength are higher along the armchair-traction than the zigzag one due to the corrugated structure along the zigzag-axis. The fracture resistances of η-LB are strongly sensitive to temperature, while their dependence on the strain-rate is relatively low. The influence of nitrogen intercalation as well as vacancy defects on elastic behavior is also determined and discussed. The results are significantly affected by the defect’s type, concentration, and location. Our findings provide useful insights for the design of LB for many applications requiring a practical large magnitude strain engineering.

In this paper, a new UV-photodetector (UV PD) design based on non-hydrogenated amorphous-silicon (a-Si) was fabricated using RF magnetron sputtering technique. The proposed structure consists on sputtering an ITO thin-film acting as a passivation layer on the a-Si layer to form a heterostructure design compatible with silicon photonics technology. X-Ray Diffraction (XRD) and UV–Vis spectra were carried out to assess the device structural and optical properties. Measurements emphasized the amorphous state of the sputtered Si thin-film. Interestingly, it was found that the elaborated device shows an exciting UV absorption capability (over than 95%) with drastically reduced visible photoresponse. The elaborated ITO/a-Si UV PD exhibits an ultra-low dark current less than 1 pA, a good responsivity of 0.13 A/W and a high I_ON/I_OFF ratio of 2.5 × 10⁴. Besides, the device demonstrates a high UV-to-Vis ratio exceeding 2.3 × 10³, thus confirming its visible blindness property. These enhancements are attributed to the role of ITO/a-Si heterostructure in promoting near-perfect UV absorption. In addition, this structure generates an electric field acting as effective driving force of the photo-induced e/h pairs, which leads to enhance the device generation/collection efficiency. Therefore, the use of ITO/a-Si design opens up new pathways for designing novel solar-blind UV PDs potentially appropriate for integrated silicon photonics technology.

This work aims to investigate the performance of a new Junctionless (JL) Ge-gate Tunneling-FET phototransistor for Infrared sensing applications. The electrical and optical performances of the considered sensor are numerically analyzed, where both switching and optoelectronic properties are reported. In this context, we address the influence of the Ge-gate doping level and high-k gate dielectric on the variation of optical Figures-of-Merit (FoMs) parameters such as responsivity, I_ON/I_OFF ratio and optical commutation speed. Interestingly, it was revealed that the proposed design provides promising pathways for enhancing the phototransistor FoMs as compared to the conventional FET-based sensors. In the second stage of our investigation, we provide a performance assessment of the proposed phototransistor by analyzing its switching capabilities as compared to the conventional design, where the device is implemented in an optical inverter circuit. The obtained results indicate the superior optoelectronic performance offered by the proposed design in comparison with the conventional devices in terms of optical commutation speed and optoelectronic gain. Therefore, this contribution can provide new insights concerning the benefit of adopting JL-TFET design for future high-performance and ultra-low power deep submicron CMOS optoelectronic applications.

Pb0 centers are the main defects at the Si(100)/SiO₂ interface in conventional MOS transistors. Besides, the charge pumping (CP) technique in which a MOSFET is repeatedly switched between inversion and accumulation has been widely used for studying single capture/emission events in deep submicron transistors. In CP, the minority carriers stored into interface traps in inversion recombine in accumulation with majority carriers from the substrate (n-channel case). This provides a CP current which can be studied. When it was accepted that in submicron MOSFETs the CP current was given by Icp = f.q.N, where f is the gate signal frequency, q the electron charge, N the number of traps entering Icp, recently, Tsuchiya and co-workers, pointed out steps heights equal to 2.q: Pb0 centers with their donor-like and acceptor-like states in the lower and upper halves of the silicon bandgap, respectively were therefore measured for the first time in submicron devices. In the present paper, the traps remaining electrically active at the Si(100)-SiO₂ interface in large area conventional MOSFETs after the full technological process including forming gas annealing are studied. This is achieved using techniques developed in recent years that use the variation of the gate signal frequency for different gate voltage swings. The trap time constant distributions that exist at this interface are studied as function of gate voltage and gate signal frequency. The results are discussed with regard to the CP models previously proposed and to CP curves simulation.

The present research letter is dedicated to a detailed analysis of a double-gate tunnel field-effect transistor (DG-TFET). The DG-TFET provides improved on-current (ION) than a conventional TFET via bandto-band (B2B) tunneling. However, DG-TFET is disadvantageous for low-power applications because of increased off-current (IOFF) due to the large ambipolar current (Iamb). In this research work, a Si/GaAs/ GaAs heterostructure DG-TFET is considered as research base for investigation of device performance. The electrical parameters of the DG-TFET device have been improved in comparison to the homostructure. The transfer (I-V) characteristics, capacitance - voltage (C-V) characteristic of homo structure Si/ Si/Si and hetero structure Si/GaAs/GaAs, DG-TFET both structures is analysed comparatively. The C-V characteristics of DG-TFET have obtained using operating frequency of 1 MHz. The ambipolar current Iamb is suppressed by 5 × 108 order of magnitude in proposed Si/GaAs/GaAs hetero DG-TFET as compared to Si/Si/Si homo DG-TFET up to the applied drain voltage very low equal to VDS = 0.5 V without affecting on- state performance. The simulation result shows a very good ION/IOFF ratio (1013) and low subthreshold slope, SS (~36.52 mV/dec). The various electrical characteristics of homo and hetero DGTFET such as on-current (ION), off - current (IOFF), time delay (ιd ), transconductance (gm) , and power delay product (PDP) have been improve in Si/GaAs/GaAs heterostructure DG-TFET and compared with Si/Si/ Si homo DG-TFET. The advantageous results obtained for the proposed design show its usability in the field of digital and analog applications.