Search Results (110)

A photovoltaic-integrated broadband photodetector based on vertically-stacked lateral-aligned III–V nanowire arrays is proposed and investigated. The staggered arrangement configuration drastically reduces the competition between solar cell and photodetector that is difficult to avoid in vertically-stacked planar structures, which enables broadband strong absorption. The lower GaAs nanowires (NWs) act as Mie scattering centers, which scatter the incident light passing through the gaps back to the upper layer, enhancing the absorption of InAs NWs over a wide wavelength range from the ultraviolet to the infrared. Meanwhile, the light trapping effect of the upper InAs nanowires improves the absorption of lower GaAs NWs. At a near-infrared wavelength of 1400 nm, the photovoltaic-integrated InAs nanowire photodetector exhibits a photocurrent density of 168.83 mA/cm² and responsivity of 0.168 A/W, 90% and 93% higher than the single layer InAs nanowires. The conversion efficiency of the GaAs nanowire solar cell is also improved after integration. This work may pave the way for the development of self-powered miniaturized broadband photodetectors. Full article

In this work, density functional theory (DFT)-based first-principles investigations are performed by Generalized Gradient Approximation (GGA) with the Perdew–Burke–Ernzerhof (PBE) functional in the CASTEP code. These simulations provide the insights of the structural, electronic, optical, thermodynamic, mechanical and hydrogen storage gravimetric ratios of lithium-based tetrahydrides (LiBH₄, LiAlH₄, and LiMnH₄) for hydrogen storage and photovoltaic (PV) applications. All these structures crystallize in orthorhombic Cmcm (No. 63) geometry with different lattice parameters and bonding strengths. Thermodynamic stabilities of hydrides are obtained by dispersion of phonons and phonon density of states. The measured band gaps of hydrides are 3.81 eV (LiBH₄), 4.60 eV (LiAlH₄), and 0.53 eV (LiMnH₄), which are calculated by GGA-PBE approach. Moreover, the optical characteristics with strong optical activity are observed from visible to ultraviolet (2 eV to 6 eV) regions. High dielectric response between 6 and 8 and absorption coefficient up to 10⁵ cm⁻¹ for hydrides are observed. Debye temperature has exceeded from 300 K to 600 K for all hydrides and saturation occurred closer to Dulong–Petit limit ~75 J mol⁻¹ K⁻¹. Mechanical stability in hydrides has been observed by Born-Hung mechanical stability criterion, demonstrating ductile nature. These natural hydrides have shown exceptional hydrogen storage capacities, as 18.5 wt% for LiBH₄, 10.6 wt% for LiAlH₄, and 6.1 wt% for LiMnH₄, are measured; these values have exceeded the U.S department of energy (DOE) targets (5.5 wt% H₂). These analyses prove that LiXH₄ (X = B, Al, Mn) hydrides are promising candidates for solid state hydrogen storage materials. Full article

Currently, the potential environmental concerns around the world for polycyclic aromatic hydrocarbon carcinogenic (PAHCs) contamination as carcinogenic compounds in industrial soils (automobile industry) are rising day by day. At present, the technology of treating contaminated soils using photocatalysts is commonly used; however, this study tested photolysis and photocatalysis through ultraviolet light (306 nm) due to its high treatment efficiency. FeCl₃ (0.3, 0.4 M) was used as an iron catalyst for each treatment in the presence of H₂O₂ (10%, 20%) as an oxidizing agent. The impact of light treatment on soils that contained various concentrations of PAHCs like naphthalene (NAP), chrysene (CRY), benzo(a) pyrene (BaP), indeno (1,2,3-cd) pyrene (IND) was investigated. The QuEChERS method was used to extract PAHCs, and a gas chromatograph mass spectrometer (GCMSMS) was used to determine concentration. The concentrations of PAHCs were measured for soils at intervals of every 2 h after exposure to ultraviolet rays. The results showed a decrease in PAHCs concentrations with increased exposure to UV irradiation, as the initial values were 26.8 ng/g (NAP), 97 ng/g (CRY), 9.1 ng/g (BaP) and 9.7 ng/g (IND), which decreased to 2.17 ng/g (NAP), 3.14 ng/g (CRY), 0.33 ng/g (BaP) and 0.46 ng/g (IND) at 20, 40, 30 and 40 h of UV exposure; moreover, with an increase in concentration of the catalyst (0.4 M FeCl₃ with 20% H₂O₂), NAP, CRY, BaP and IND became undetectable at 8, 26, 14 and 20 h, respectively. It was concluded that a significant effect of ultraviolet rays on the photolysis of PAHCs, along with Photovoltaic at 306 nm wavelength, was observed while using FeCl₃ (0.4 M) combined with H₂O₂ (20%) produced better results in a shorter time compared to FeCl₃ (0.3 M) with H₂O₂ (10%). Full article

The development of thin-film organic solar cells (TFOSCs) is pivotal for advancing sustainable energy technologies because of their potential for low-cost, lightweight, and flexible photovoltaic applications. In this study, silver-doped copper sulfide (CuS/Ag) metal nanoparticles (MNPs) were successfully synthesized via a wet chemical method. These CuS/Ag MNPs were incorporated at varying concentrations into a poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) blend, serving as the active layer to enhance the photovoltaic performance of the TFOSCs. The fabricated TFOSC devices were systematically evaluated based on the optical, electrical, and morphological characteristics of the active layer. By varying the concentration of CuS/Ag MNPs, the influence of nanoparticle doping on photocurrent generation was investigated. The device incorporating 1% CuS/Ag MNPs exhibited the highest power conversion efficiency (PCE) of 5.28%, significantly outperforming the pristine reference device, which achieved a PCE of 2.53%. This enhancement is attributed to the localized surface plasmon resonance (LSPR), which augments charge transport and increases optical absorption. The CuS/Ag MNPs were characterized using ultraviolet–visible (UV-Vis) absorption spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM), and energy-dispersive dispersion (EDX) analysis. These findings underscore the potential of CuS/Ag MNPs in revolutionizing TFOSCs, paving the way for more efficient and sustainable solar energy solutions. Full article

We fabricated TiO₂ thin films using the sol–gel method, incorporating TiO₂ nanoparticle sizes of 25 nm on the fluorine-doped tin oxide (FTO) substrates by spin coating and annelation at 600 °C. The influence of incorporating TiO₂ particles on the surface morphology, optical properties, and photovoltaic performance of TiO₂ thin-film dye-sensitized solar cells (DSSC) was examined. Structural characterization was analyzed using X-ray diffraction (XRD), while the morphologies were analyzed using scanning electron microscopy (SEM). The transmittance and absorbance of films were measured using an ultraviolet (UV)–visible (VIS)–near-infrared (NIR) spectrophotometer. The current–voltage (I-V) property was evaluated under simulated solar irradiation. The results demonstrated that the incorporation of TiO₂ particles enhanced the efficiency of DSSCs. The photovoltaic performance of DSSCs was improved with TiO₂ nanoparticle incorporation. The optimized DSSC incorporated TiO₂ films (TIFNA). TIFNA achieved a Jsc of 14.49 mA/cm², Voc of 0.69 V, fill factor of 60.5%, and efficiency of 6.05%, compared to 4.23% for the DSSC with unincorporated TiO₂ thin film. The improved performance was attributed to increased dye adsorption, better crystallinity, and enhanced electron transport. Full article

In this study, lanthanum–nitrogen co-doped titanium dioxide (La-N-TiO₂) thin films were fabricated using Ion Beam Assisted Deposition (IBAD) and subjected to accelerated ultraviolet (UV) aging experiments to systematically investigate the impact of co-doping on the films’ resistance to UV aging. X-ray diffraction (XRD) analysis revealed that La-N co-doping inhibits the phase transition from anatase to rutile, significantly enhancing the phase stability of the films. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) characterizations indicated that co-doping increased the density and surface uniformity of the films, thereby delaying the expansion of cracks and increase in roughness induced by UV exposure. Energy-dispersive X-ray spectroscopy (EDS) results confirmed the successful incorporation of La and N into the TiO₂ lattice, enhancing the chemical stability of the films. Contact angle tests demonstrated that La-N co-doping markedly improved the hydrophobicity of the films, inhibiting the rapid decay of hydrophilicity during UV aging. After three years of UV aging, the co-doped films maintained high structural integrity and photocatalytic performance, exhibiting excellent resistance to UV aging. These findings offer new insights into the long-term stability of photovoltaic self-cleaning materials. Full article

This work presents a high-performance novel photodetector based on two-dimensional boron nitride (BN) nanosheets functionalized with gold nanoparticles (Au NPs), offering ultra-broadband photoresponse from 0.25 to 5.9 μm. Operating in both photovoltaic and photoconductive modes, the device features rapid response times (<0.5 ms), high responsivity (up to 1015 mA/W at 250 nm and 2.5 V bias), and thermal stability up to 100 °C. The synthesis process involved CO₂ laser exfoliation of hexagonal boron nitride, followed by gold NP deposition via RF sputtering and thermal annealing. Structural and compositional analyses confirmed the formation of a three-dimensional network of atomically thin BN nanosheets decorated with uniformly distributed gold nanoparticles. This architecture facilitates plasmon-enhanced absorption and efficient charge separation via heterojunction interfaces, significantly boosting photocurrent generation across the deep ultraviolet (DUV), visible, near-infrared (NIR), and mid-infrared (MIR) spectral regions. First-principles calculations support the observed broadband response, confirming bandgap narrowing induced by defects in h-BN and functionalization by gold nanoparticles. The device’s self-driven operation, wide spectral response, and durability under elevated temperatures underscore its strong potential for next-generation broadband, self-powered, and wearable sensing and optoelectronic applications. Full article

Two-dimensional (2D) materials have revolutionized the field of optoelectronics by offering exceptional properties such as atomically thin structures, high carrier mobility, tunable bandgaps, and strong light–matter interactions. These attributes make them ideal candidates for next-generation photodetectors operating across a broad spectral range—from ultraviolet to mid-infrared. This review comprehensively examines the recent progress in 2D material-based photodetectors, highlighting key material classes including graphene, transition metal dichalcogenides (TMDCs), black phosphorus (BP), MXenes, chalcogenides, and carbides. We explore their photodetection mechanisms—such as photovoltaic, photoconductive, photothermoelectric, bolometric, and plasmon-enhanced effects—and discuss their impact on critical performance metrics like responsivity, detectivity, and response time. Emphasis is placed on material integration strategies, heterostructure engineering, and plasmonic enhancements that have enabled improved sensitivity and spectral tunability. The review also addresses the remaining challenges related to environmental stability, scalability, and device architecture. Finally, we outline future directions for the development of high-performance, broadband, and flexible 2D photodetectors for diverse applications in sensing, imaging, and communication technologies. Full article

The rapid growth of the private space industry has intensified the demand for lightweight, efficient, and cost-effective photovoltaic technologies. Metal halide perovskite solar cells (PSCs) offer high power conversion efficiency (PCE), mechanical flexibility, and low-temperature solution processability, making them strong candidates for next-generation space power systems. However, exposure to extreme thermal cycling, high-energy radiation, vacuum, and ultraviolet light in space leads to severe degradation. This study addresses these challenges by introducing three key design strategies: self-healing perovskite compositions that recover from radiation-induced damage, gradient buffer layers that mitigate mechanical stress caused by thermal expansion mismatch, and advanced encapsulation that serves as a multifunctional barrier against space environmental stressors. These approaches enhance device resilience and operational stability in space. The design strategies discussed in this review are expected to support long-term power generation for low-cost satellites, high-altitude platforms, and deep-space missions. Additionally, insights gained from this research are applicable to terrestrial environments with high radiation or temperature extremes. Perovskite solar cells represent a transformative solution for space photovoltaics, offering a pathway toward scalable, flexible, and radiation-tolerant energy systems. Full article

The sol–gel synthesis of titanium dioxide (TiO₂) nanostructures is investigated in the present work in order to optimize synthesis parameters and enhance the optical properties and cost-effectiveness of the obtained materials. TiO₂ is widely used in photocatalysis, photovoltaics, and environmental applications due to its high stability, tunable band gap, and strong light absorption. The sol–gel method offers a scalable, cost-effective route for producing nanostructured TiO₂, although the precise control over particle morphology remains challenging. For this reason, in the present work, a statistical design of experiments (DOE) approach is employed to systematically refine reaction conditions through the manipulation of precursor concentrations, solvent ratios, and reaction volume. The experimental results obtained indicate that acetic acid is a key catalyst and stabilizing agent, significantly improving nucleation control and particle formation. Moreover, it is also shown that solvent dilution, particularly with acetic acid, leads to the formation of TiO₂ nanorods with enhanced optical properties. Additionally, scanning electron micrographs revealed that controlled synthesis conditions can reduce the particle size distribution and improve structural uniformity. Moreover, X-ray diffraction analyses confirmed the formation of a pure anatase crystalline phase, while ultraviolet–visible spectroscopy analyses indicated the existence of an optimal band gap for photocatalytic applications. Finally, the cost analysis showed that acetic acid-assisted synthesis can reduce production costs and simultaneously maintain high optical properties. Therefore, the present study highlights that proper manipulation and control of reaction conditions during sol–gel syntheses can allow the manufacture of high-performance TiO₂ nanomaterials for advanced technological applications, also providing a foundation for the development of cost-effective materials. Full article

The corrosion within photovoltaic (PV) systems has become a critical challenge to address, significantly affecting the efficiency of solar-to-electric energy conversion, longevity, and economic viability. This review provides a comprehensive analysis of electrochemical corrosion mechanisms affecting solar panels and environmental factors that accelerate material degradation, including (i) humidity, (ii) temperature fluctuations, (iii) ultraviolet radiation, and (iv) exposure to saline environments, leading to reduced performance and premature failures. The role of encapsulation materials, solder interconnections, and conductive coatings in the corrosion formation process is examined. Various electrochemical and surface characterization techniques provide insights into material degradation and corrosion mechanisms within panels. Essential parameters are presented and discussed, including materials used, geographical location of analysis, environmental considerations, and corrosion characterization techniques, to enhance the assessment of solar panels. This review emphasizes the importance of corrosion management for sustainable PV systems and proposes future research directions for developing more durable materials and advanced coatings. Full article

This paper presents a new model for low-cost solar-powered Automatic Weather Stations based on the ESP-32 microcontroller, modern sensors, and intelligent forecasts for Brasilia. The proposed system relies on compact, multifunctional sensors and features an open-source firmware project and open-circuit board design. It includes a BME688, AS7331, VEML7700, AS3935 for thermo-hygro-barometry (plus air quality), ultraviolet irradiance, luximetry, and fulminology, besides having a rainfall gauge and an anemometer. Powered by photovoltaic panels and batteries, it operates uninterruptedly under variable weather conditions, with data collected being sent via WiFi to a Web API that adapts the MZDN-HF (Meteorological Zone Delimited Neural Network–Hourly Forecaster) model compilation for Brasilia to produce accurate 24 h multivariate forecasts, which were evaluated through MAE, RMSE, and R² metrics. Installed at the University of Brasilia, it demonstrates robust hardware performance and strong correlation with INMET’s A001 data, suitable for climate monitoring, precision agriculture, and environmental research. Full article

Perovskite solar cells (PSCs) have been regarded as a revolutionary technology in the photovoltaic field, offering a promising pathway for efficient and cost-effective solar energy conversion and demonstrating broad prospects for future green energy technologies. However, critical stability challenges, specifically degradation induced by humidity, light, or heat, severely hinder the commercialization of this technology. Specifically, ultraviolet (UV) radiation in the solar spectrum is a major factor leading to the degradation of perovskite materials. This review focuses on the challenges and strategies for addressing the photostability issues of PSCs. A variety of strategies have been explored, which can be classified as external protection (such as UV-blocking encapsulation technologies) and internal optimization approaches (including precise compositional tuning, the incorporation of functional additives, interface engineering, and improvements to charge transport layers). Finally, this review delves into the key scientific challenges and technological bottlenecks currently faced in addressing the UV stability of PSCs and proposes future directions for solving UV stability issues. It also provides an outlook on the future development prospects of these technologies. Full article

Conductive polymers play a crucial role in the advancement of modern technologies, particularly in the field of organic photovoltaics (OPVs). Due to advantages such as flexibility, low specific weight, ease of processing, and low production costs, polymeric materials present an attractive alternative to traditional photovoltaic materials. This study investigates the properties of a polymer blend composed of PCPDTBT (donor) and PNDI(2HD)2T (acceptor), used as the active layer in bulk heterojunction (BHJ) solar cells. The motivation behind this research was the search for a novel n-type polymer material with potentially better properties than the commonly used P(NDI2OD-T2). Comprehensive characterization of thin films made from the individual polymers and their blend was conducted using Fourier Transform Infrared Spectroscopy (FTIR), Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), Ultraviolet-Visible Spectroscopy (UV-Vis), four-point probe conductivity measurements, and photovoltaic testing. The prepared films were continuous, uniform, and exhibited low surface roughness (R_a < 2.5 nm). Spectroscopic analysis showed that the blend absorbs light in a broad range of the spectrum, with slight bathochromic shifts compared to individual polymers. Electrical measurements indicated that the blend’s conductivity (9.1 µS/cm) was lower than that of pure PCPDTBT but higher than that of PNDI(2HD)2T, with an optical band gap of 1.34 eV. Photovoltaic devices fabricated using the blend demonstrated an average power conversion efficiency (PCE) of 6.45%, with a short-circuit current of 14.37 mA/cm² and an open-circuit voltage of 0.89 V. These results confirm the feasibility of using PCPDTBT:PNDI(2HD)2T blends as active layers in BHJ solar cells and provide a promising direction for further optimization in terms of polymer ratio and processing conditions. Full article

This study presents an effective strategy to enhance the efficiency and stability of perovskite solar cells (PSCs) by integrating neodymium-doped upconversion nanoparticles (UCNPs) coated with a TiO₂ shell into the mesoporous electron transport layer. The incorporation of neodymium (Nd³⁺) as a novel sensitizer shifts the near-infrared (NIR) absorption band away from the water vapor absorption region in the solar spectrum. This modification enables UCNPs to efficiently convert NIR light into ultraviolet (UV) and blue wavelengths, which are readily absorbed by TiO₂, generating additional charge carriers and improving photovoltaic performance. The optimized PSCs, fabricated by blending 30% UCNPs@TiO₂ with commercial TiO₂ paste, achieved a peak power conversion efficiency (PCE) of 21.71%, representing a 20.4% improvement over the control (18.04%). This enhancement included a 0.9% increase in the open-circuit voltage (V_oc), a 6.6% rise in the short-circuit current density (J_sc), and an 11.9% boost in the fill factor (FF). Additionally, the optimized PSCs exhibited remarkable stability, retaining over 90% of their initial PCE after 900 h in humid conditions, compared to only 70% for the control. These improvements result from enhanced light absorption, reduced moisture infiltration, and lower defect-related recombination. This approach provides a promising pathway for developing highly efficient and durable PSCs. Full article