Sunlight Research Articles

Effective Lifetime of Nonequilibrium Carriers in Perovskite‐Inspired Cu2AgBiI6

Perovskite‐inspired materials (PIMs) are potential alternatives to lead halide perovskites, as they not only inherit the benign optoelectronic properties but also diminish the stability and toxicity issues of lead halide perovskites. As a newly discovered PIM, Cu2AgBiI6 has exhibited promising potential for photovoltaic applications. However, studies on its fundamental properties related to photovoltaic performance are scarce, particularly from a theoretical perspective. Herein, the effective lifetime of nonequilibrium carriers (photo‐excited charge carriers) is systematically investigated, a critical property affecting the photovoltaic performance of Cu2AgBiI6, based on the nonadiabatic molecular dynamics simulations. It is found that under the standard solar spectrum illumination, the dominant recombination mechanism affecting the effective lifetime can be band‐to‐band nonradiative decay, band‐to‐band radiative decay, or Shockey–Read–Hall defect‐assisted decay. The specific mechanism is highly dependent on the radiative recombination coefficient and the density of defect recombination levels. The effective lifetime can vary from 0.1 ms to 10 ns. When considering different illumination conditions (generation rates), Auger decay can also become the dominant recombination mechanism, with the effective lifetime varying from 0.1 s to 0.1 ns. These findings can be vital for further experimental researches aimed at enhancing the power conversion efficiency of Cu2AgBiI6‐based solar devices.

The epidemiological profile of cancer in Beni Mellal: a cross-sectional descriptive study

In Morocco, where cancer is a major public health problem, the characteristics of cancer in the Beni Mellal-Khenifra region of Morocco are unknown. Our objective was to establish the epidemiological profile of cancer in this region and the main risk factors influencing cancer. We conducted a cross-sectional study, including all types of cancer, with a sample of 100 patients at the Beni Mellal regional oncology center. Data collected in June and July 2021 using a questionnaire, pre-tested, and analyzed using SPSS and Excel. The questionnaire included sections on cancer-related clinical characteristics and other items related to cancer risk exposures. Gyneco-mammary cancers occupied the first position (49%). The most common localization of cancer in women was breast cancer, with a proportion of 63% of cases recorded during the period studied. In men, lung cancer was the most frequent location at 17%. We found some possible risk factors for cancer: tobacco and alcohol use, dietary habits, use of hormonal contraceptive methods, low income, pollution, sun radiation, exposure to asbestos, family history of cancer, and diseases associated with cancer. Women’s cancers are very common in the region. Several factors are responsible for this frequency. These results suggest several avenues for further research.

Heat and Mass Transfer within Unsteady Nanofluid Movement in the Presence of Sustained Solar Radiation

The unsteady movement of nanofluid on porous inclined media is essential for absorbing and transferring heat from solar radiation. From renewable energy sources, solar is limitless, sustainable and universally accessible without creating conflict. In this study, heat and mass transfer have been explored by unsteadily moving nanofluid with the occurrence of Sun rays and viscous dissipation. Tiwari-Das and Darcy-Forchheimer models are encompassed with convective heat transfer and mass suction/injection. Then, the non-linear higher-order set of ordinary differential equations was obtained from fundamental non-linear partial differential equations by using similarity transformation. Both semi-analytical and numerical strategies have been adopted. Comparisons with published articles have detected and observed similar outcomes. Accordingly, thermal Grashof number elevates nanofluid motion while postponing drag force creation. Permeability and Darcy’s number have publicized a contradictory trend in the nanofluid’s movement and temperature. Nanofluid’s temperature expands by incident solar radiation and Eckert number but not by absorption. There is less heat transfer rate by convective than conductive through magnifying magnetic field and nanoparticles’ concentration. Nanofluid constructed by Cu–H2O produces more drag force and less heat transfer rate than that of Cu–C3H8O2. Heat transfer from solar energy is applicable for cooking, heating water and producing electricity.

Dual surface defects induced efficient interfacial electron transfer in S-scheme hollow ZnO@ZnS heterojunction for uranium (VI) removal

Photocatalytic reduction is a promising way to remove radioactive uranium U(VI) in wastewater. Herein, an S-scheme ZnO@ZnS heterojunction with hollow structure and dual-vacancies of Zn and S (ZnV, SV) is developed. The hollow confined space enhances light trapping ability through multiple light scattering and reflection, while the existence of vacancies extends light absorption, further enhancing the utilization of solar spectrum. Furthermore, the density function theory (DFT) calculations demonstrate that co-sharing of metal atoms at the interface and the ZnV and SV dual-vacancies induce enhanced internal electric field (IEF), leading to facilitated S-scheme charge transfer, thereby resulting in improved retention of redox potential and suppressed carrier recombination dynamics. ZnO@ZnS shows a highest U(VI) removal rate of 96.48% along with a highest U enrichment of 514.33 mg/g, which is 3.6 and 2.7-folds enhanced compared to pristine ZnO and ZnS, respectively. Through various quenching experiments, a potential new mechanism for the catalytic reduction of U(VI) is proposed. Our findings reveal the involvement of h+ in the reaction, highlighting its significant catalytic role in the reduction process. Moreover, ZnO@ZnS performs excellent U(VI) extraction ability in open-air conditions without any sacrificial agents, revealing the great significance for practical applications.

Unlocking the Power of Solar Synergy: Enhanced Nitrophenol Degradation using ADGCAAQ Photocatalyst

The remarkable mechanical and chemical characteristics of graphene have garnered significant interest in scientific investigations aimed at addressing severe environmental problems and energy shortages. A concerning problem is the careless disposal of industrial wastes that contain a variety of organic contaminants in water bodies. In order to create the ADGCAAQ light harvesting photocatalyst, a simple and extremely effective condensation process involving 1, 4-diamino anthraquinone (AAQ) and graphene generated from aloe vera (ADG) has been urbanized. Several approaches are used to analyze the newly constructed photocatalyst, indicating that it has the requisite potential to degrade 4-nitrophenol. By analyzing the degradation rate and order reaction of the degradation process, the kinetics of the degradation route have been used to analyze the mechanistic pathway for the degradation of 4-nitrophenol using a reducing agent and the ADGCAAQ photocatalyst. Under outside solar spectrum conditions, the photocatalytic activity of ADGCAAQ photocatalyst tested with 4-nitrophenol shows significant degradation efficiency with reducing agent H2O2.

Forward modeling of the Mg I 12.32 μm line from a 3D magnetohydrodynamic model of an enhanced network

Context. The Mg I 12 μm lines, 12.22 and 12.32 μm, represent a pair of emission lines, and their line cores originate around the temperature minimum region. These lines exhibit the highest ratio of Zeeman to Doppler broadening in the infrared solar spectrum, making them crucial for accurately investigating the solar magnetic field. Aims. We synthesized the Mg I 12.32 μm Stokes profiles from a 3D magnetohydrodynamic (MHD) model and studied the validity of different methods for extracting the magnetic field. The observational profiles at different spatial resolution were simulated, which are helpful for the design of future solar telescopes with large apertures. Methods. We used a 3D MHD simulation model for an enhanced network computed using the Bifrost code. We performed nonlocal thermal equilibrium calculations for Stokes profiles of the Mg I 12.32 μm line using the Rybicki–Hummer code. Results. From the simulation we determined the average formation height of the Mg I 12.32 μm line to be around 450 km. The various solar features have different formation heights, and the variance of formation height in magnetic concentration regions is about 160 km. The wavelength-integrated method is proven effective in calibrating the integrated Stokes profiles to obtain the longitudinal (Bl) and horizontal (BH) field components for weak magnetic fields; the Bl is below 300 G. Furthermore, the weak field approximation was found to be valid only for estimating magnetic fields with Bl below 150 G. The Stokes I profiles clearly show Zeeman triple splitting around the magnetic flux concentration with a grid resolution of 48 km. We determined that a resolution of 0.97″, equivalent to the diffraction limit of a telescope with a diameter of 3.2 m, was necessary to detect the Zeeman splitting for the simulated snapshot. Our results from this 3D MHD model are valuable for interpreting data from the Accurate Infrared Magnetic Field Measurements of the Sun (AIMS) telescope and designing future solar infrared telescopes.

Comprehensive performance analysis of CST-PV system based on spectral beam splitting film

Abstract In this paper, a novel linear Fresnel concentrator (LFC) with a rotating platform was constructed, and a novel concentrated solar thermal and photovoltaic (CST-PV) hybrid system utilizing spectral beam splitting was established on the LFC. A spectral beam-splitting film (SBSF) was coated on the PV cell’s inner glass wall, replacing the LFC’s primary reflector. The SBSF can transmit the solar spectrum of 300-1100 nm to the photovoltaic (PV) cells and reflect the remaining solar wavelengths to the absorber to generate heat. The LFC’s cosine efficiency and end efficiency after azimuthal compensation by a rotating platform were calculated through theoretical analysis. The effects of temperature on the efficiency of PV and linear Fresnel solar systems were studied through experimental and numerical simulations. The comprehensive utilization efficiency evaluation method was established. The results show that the LFC’s end efficiency and cosine efficiency in this paper, after azimuthal compensation, increased by 31.7% and 33.7%, respectively, compared with the east-west and north-south axis placement. The comprehensive utilization efficiency of the CST-PV system based on SBS is 61.58%, which increased by 13.47% compared to that of the single fixed PV system.

Solar Tracking and Monitoring System

Abstract: We will eventually have to deal with the depletion of fossil fuels and other non-renewable energy sources as they are running out rapidly. Having a large number of renewable alternative energy sources is crucial. The sun's radiation properties meet both requirements. As a result, new technologies focused on solar energy harvesting are starting to appear. Concentrated or photovoltaic panels may yield the highest efficiency. Due to the planet's rotation, which causes humans to view the sun at different times of the day the efficiency may reduce. Devices that direct a solar panel or concentrating panel during the day are incorporated in the design, along with light-trackers to boost the system's effectiveness. A solar tracker can monitor the sun's radiation in single direction. The device monitors daily tilt of the sun for optimal performance. The work focuses on the fundamentals of solar panel parameters and their application, as well as the design and construction of an automatic solar tracker prototype utilizing Arduino code based on microcontroller. By simulating the sun's 12-month tracking in a matter of minutes, the device incorporates automation mechanisms into the tracking system.

Geopolymer Paving Blocks Made From Fly Ash and Bagasse Ash Under Different Curing Conditions

This research aimed to study the geopolymer paving blocks made from fly ash and bagasse ash under different curing conditions. The fly ash was replaced by bagasse ash at 10, 20 and 30% by weight of the binder. Sodium hydroxide and sodium silicate solutions were used as activated solutions. Three curing methods were studied: curing with plastic wrap (PT), curing at 35 °C for 1 hour (OV), and curing with sunlight (SU). Compressive strength and water absorption were investigated. The surface characteristics of the geopolymer paving block were studied using microstructure techniques. Sun curing provided the highest compressive strength. The water absorption values increased with an increase in the replacement percentage of bagasse ash. The surface of the geopolymer paving blocks showed remnants of the starting materials from the reaction. The geopolymer paste from the geopolymerization reaction was also found. This indicated the beneficial use of waste materials to produce environmentally friendly building materials.

Durable self-cleaning anti-fog and antireflective micro-nano structures fabricated by laser marker ablation of Si coated glass

This study presents an approach for fabricating super hydrophilic self-cleaning anti-fog micro-nano structures on silicon-coated glass utilizing a laser marking machine. The surface features a periodic microstructure interspersed with irregular nanoparticles, which contribute to its durable superhydrophilicity, maintaining a 0° contact angle for up to one year—the longest duration recorded to date. Moreover, it sustained its anti-fogging and self-cleaning abilities for 467 days, establishing the lengthiest duration for maintaining a 0° contact angle and retaining anti-fogging performance without visible deterioration. The sample also retained excellent anti-fogging and self-cleaning properties even after 43 days of outdoor exposure. Such remarkable performance was attributed not only to surface chemistry and roughness but also to the presence of dense, uniform, and minimally varying microstructures. The unique structure also enhanced the solar spectrum (AM 1.5) weighted average transmission by 3.84 % over control glass in the wavelength range of 400–1100 nm. It holds promising potential for use in automotive rearview mirrors, windows, and solar cells.

A stretchable gel-type floating material boosts photo-Fenton-adsorption for efficient purification of mineral processing wastewater

Organic floatation reagents and heavy metals are the main pollutants produced from mineral processing industries. Traditional powder material is facing the challenges of difficult solid–liquid separation and fast dissolution during the wastewater treatment. In this paper, a stretchable halloysite based gel-type floating material (GF-HNTs@Mo/Fe) was synthesized to trigger photo-Fenton and adsorption reaction for the purification of the beneficiation wastewater. GF-HNTs@Mo/Fe exhibits good hydrophilicity which is very beneficial to suspend in water to absorb sun light and contact with pollutants under the force of hydrogen bond. Compared to single HNTs@MoS2/FeOOH powder material, GF-HNTs@Mo/Fe can be fabricated to any size and reserve most performance. Under optimized conditions, GF-HNTs@Mo/Fe can continuously remove aniline aerofloat (AAF), Cd2+ and COD both from simulated wastewater and actual lead zinc copper ore beneficiation wastewater over ultra-long time of 288 h, and still remain over 50 % treatment ability. Especially, after 13d treatment of actual beneficiation wastewater, 97.12 % of Cd2+, 85.46 % of AAF, 53.28 % of COD and 46.67 % of TOC still could be eliminated by GF-HNTs@Mo/Fe. Owing to the robust mechanical strength of GF-HNTs@Mo/Fe, it can be easily recovered for reuse and avoid secondary pollution. This GF-HNTs@Mo/Fe floating photo-Fenton-adsorption system not only solves solid–liquid separation issue in powder system, but decreases the drawback of performance loss when powder material was fabricated to bulk material.

Stability of Plasmonic Mg-MgO Core-Shell Nanoparticles in Gas-Phase Oxidative Environments.

Magnesium is a recent addition to the plasmonic toolbox: nanomaterials that efficiently utilize photons' energy due to their ability to sustain localized surface plasmon resonances. Magnesium nanoparticles protected by a native oxide shell can efficiently absorb light across the solar spectrum, making them a promising photocatalytic material. However, their inherent reactivity toward oxidation may limit the number of reactions in which Mg-MgO can be used. Here, we investigate the stability of plasmonic Mg-MgO core-shell nanoplates under oxidative conditions. We demonstrate that the MgO shell stabilizes the metallic Mg core against oxidation in air at up to 400 °C. Furthermore, we show that the reactivity of Mg-MgO nanoplates with water vapor (3.5 vol % in N2) decreases with temperature, with no oxidation of the Mg core detected from 200 to 400 °C. This work unravels the potential of Mg-MgO nanoparticles for a broad range of catalytic transformations occurring in oxidative environments.

Hybrid minigrid system comprising energy storage systems with optimal frequency control empowering the new Egypt large optical telescope site

Proposed hybrid minigrid two area system simulation model encompassing Photo Voltaic (PV) system, Wind Turbines (WT), diesel generators and Energy Storage Systems with intelligent based optimal Frequency Controllers (FCs) empowering the new Egypt large optical telescope (ELOT) site is presented in this research. Technical study and specifications for a PV solar system of 1000 Kw is introduced. Intelligent fine optimized Proportional Integral Derivative (PID) and Fuzzy self-tuned PID (FSTPID) controllers are designed through applying Harris Hawk optimizer (HHO). The proposed HHO employed method performance is validated under number of eventualities which include vacillations of load, sun radiation and wind speed. The objective function and control parameters are the integral time summation of absolute deviations and the parameters of controllers, consecutively. The system dynamic response and simulation results show that the proposed HHO based FSTPID type FCs are effective in reducing frequency and tie line power signals’ deviations in a diminutive time for such minigrid hybrid system. For supplemental validations, simulation results obtained are compared with genetic algorithm to get the proposed controllers’ gains.

Solar-Driven Biomass Reforming for Hydrogen Generation: Principles, Advances, and Challenges.

Hydrogen (H2) has emerged as a clean and versatile energy carrier to power a carbon-neutral economy for the post-fossil era. Hydrogen generation from low-cost and renewable biomass by virtually inexhaustible solar energy presents an innovative strategy to process organic solid waste, combat the energy crisis, and achieve carbon neutrality. Herein, the progress and breakthroughs in solar-powered H2 production from biomass are reviewed. The basic principles of solar-driven H2 generation from biomass are first introduced for a better understanding of the reaction mechanism. Next, the merits and shortcomings of various semiconductors and cocatalysts are summarized, and the strategies for addressing the related issues are also elaborated. Then, various bio-based feedstocks for solar-driven H2 production are reviewed with an emphasis on the effect of photocatalysts and catalytic systems on performance. Of note, the concurrent generation of value-added chemicals from biomass reforming is emphasized as well. Meanwhile, the emerging photo-thermal coupling strategy that shows a grand prospect for maximally utilizing the entire solar energy spectrum is also discussed. Further, the direct utilization of hydrogen from biomass as a green reductant for producing value-added chemicals via organic reactions is also highlighted. Finally, the challenges and perspectives of photoreforming biomass toward hydrogen are envisioned.

Boosting conversion efficiency by bandgap engineering of ecofriendly antimony trisulfide indoor photovoltaics via a modeling approach

With the exponential growth of the Internet of Things (IoT), indoor photovoltaics (IPVs) have emerged as a pivotal technology for powering low-power devices, drawing heightened interest due to their adaptability to indoor environments. The Photovoltaic Conversion Efficiency (PCE) of IPV cells is critically dependent on their ability to match the indoor spectrum with the device's response characteristics. In this realm, Antimony Trisulfide (Sb2S3), characterized by its wide bandgap and high absorption coefficient, emerges as a promising candidate for low-light applications. Our study focuses on the modeling and numerical analysis of Sb2S3 thin-film IPV cells by wxAMPS software, aiming to refine both the device structure and its photoelectric performance for effective indoor light harvesting. In a strategic shift from conventional CdS materials, we utilized SnO2—known for its high transmissivity, non-toxicity, and wide bandgap—as the electron transport layer (ETL) in Sb2S3 IPV cells. This substitution notably enhanced the short-wave response, elevating the spectral response from 45 % to 80 % at 400 nm. Additionally, we introduced a bandgap-tunable ZnOS buffer layer. This innovation proved instrumental in rectifying the band alignment mismatch between SnO2 and Sb2S3 layer, thereby optimizing interfacial electron transport properties. The integration of the ZnOS buffer layer effectively improved the fill factor from 40.0 % to 64.7 % of the Sb2S3 IPV cell by solving the band mismatch problem. The resulting optimized Sb2S3 IPV cell demonstrated exceptional response characteristics across the full visible spectrum (400–750 nm) and showed notable photoelectric performance under both fluorescent lamps (FLs) and light-emitting diodes (LEDs). Moreover, a detailed analysis was conducted on the performance differences of the device under indoor light sources compared to solar spectrum conditions, along with the underlying mechanisms. Finally, the Sb2S3 IPV cell achieved a peak theoretical efficiency of 46.25 % under cold white FL lighting, a testament to the optimal match between the device structure and this specific emission power spectrum. This modeling research not only underscores the feasibility of employing antimony-based photovoltaic technologies in indoor settings but also offers theoretical guidance for further advancements in this domain.

Solar-matched S-scheme ZnO/g-C3N4 for visible light-driven paracetamol degradation

In pursuit of an efficient visible light driven photocatalyst for paracetamol degradation in wastewater, we have fabricated the ZnO/g-C3N4 S-Scheme photocatalysts and explored the optimal percentage to form a composite of graphitic carbon nitride (g-C3N4) with zinc oxide (ZnO) for enhanced performance. Our study aimed to address the urgent need for a catalyst capable of environmentally friendly degradation of paracetamol, a common pharmaceutical pollutant, using visible light conditions. Here, we tailored the band gap of a photocatalyst to match solar radiation as a transformative advancement in environmental catalysis. Notably, the optimized composite, containing 10 wt.% g-C3N4 with ZnO, demonstrated outstanding paracetamol degradation efficiency of 95% within a mere 60-min exposure to visible light. This marked enhancement represented a 2.24-fold increase in the reaction rate compared to lower wt. percentage composites (3 wt.% g-C3N4) and pristine g-C3N4. The exceptional photocatalytic activity of the optimized composite can be attributed to the band gap narrowing that closely matched the maximum solar radiation spectrum. This, coupled with efficient charge transfer mechanisms through S-scheme heterojunction formation and an abundance of active sites due to increased surface area and reduced particle size, contributed to the remarkable performance. Trapping experiments identified hydroxyl radicals as the primary reactive species responsible for paracetamol photoreduction. Furthermore, the synthesized ZnO/g-C3N4 composite exhibited exceptional photostability and reusability, underscoring its practical applicability. Thus, this research marks a significant stride towards the development of an effective and sustainable visible light photocatalyst for the removal of pharmaceutical contaminants from aquatic environments.

Synergetic Triple Absorber Based High‐Efficiency Solar Cell Design

AbstractComputational analysis of triple absorber‐based solar cell structure is undertaken. This solar cell device configuration allows better utilization of the incident solar spectrum. Three different absorbers with a band gap in the range 1–1.5 eV are sandwiched between high‐doped p+ and n+ regions in descending order of electron affinity to form an energy‐matched multiple absorber device. A comprehensive analysis of key device parameters influencing performance, including band gap, conduction band alignment, interfacial defects, and thickness, is presented. The optimized triple absorber device shows beyond Shockley–Queisser limit (SQ limit) performance under the constraint of passivated interfaces with defect density below 1013 cm−2. Wide spectrum coverage leads to high short circuit current and an efficiency of 40.3%, which is higher than the SQ limit for single band gap solar cell.

The Lost “Linant de Bellefonds Stela” of the Chief-Treasurer Maya and its Hymn and Prayer to the Sun-God

Summary Publication of a new stela of the Chief-Treasurer Maya (time of Tutankhamun-Horemheb) with a long hymn addressed to the rising sun. The closest versions of the text are those of pNakht (London BM EA 10471, 21), the London stela of Horemheb (BM EA 551), and the pyramidion of Amenhotep Huy in the Rijksmuseum van Oudheden, Leiden (AM 6-b) – one sequence about the sun rays and the Haunebut (line 5) is original in view of the available documentation. The stela (now lost) which was in the possession of Linant de Bellefonds in 1850, is only known thanks to a handwritten copy by Auguste Mariette. There can be no doubt that it comes from the tomb of Maya at Saqqara.

Unveiling excitons in two-dimensional -pnictogens.

In this paper, we investigate the optical, electronic, vibrational, and excitonic properties of four two-dimensional -pnictogen materials-nitrogenene, phosphorene, arsenene, and antimonene-via density functional theory calculations and the Bethe-Salpeter equation. These materials possess indirect gaps with significant exciton binding energies, demonstrating isotropic behavior under circular light polarization and anisotropic behavior under linear polarization by absorbing light within the visible solar spectrum (except for nitrogenene). Furthermore, we observed that Raman frequencies red-shift in heavier pnictogen atoms aligning with experimental observations; simultaneously, quasi-particle effects notably influence the linear optical response intensively. These monolayers' excitonic effects lead to optical band gaps optimized for solar energy harvesting, positioning them as promising candidates for advanced optoelectronic device applications.

Comparisons of Direct Normal Irradiation for the Optimization of Active Daylighting Systems

Active daylighting technology, encompassing techniques for utilizing natural light without converting it into heat or electrical energy, proves highly beneficial in sun-rich countries like Morocco. Unlike solar technologies, which capture global radiation, daylighting technology specifically leverages direct sun radiation. This study focuses on three semi-empirical models: Perrin de Brichambaut, Kasten, and Ghouard, utilizing data from the PVGIS website to develop and evaluate these systems. Comparison of experimentally obtained direct normal irradiation results against these models and the PVGIS website identifies the Kasten model as the most suitable choice, supported by the high R2 values of 0.9954, 0.9933, 0.9951, and 0.9906 for winter, spring, summer, and autumn, respectively. Furthermore, the model exhibits a minimum Mean Absolute Error (MAE) of 12.34, 24.29, 25.93, and 29.51 W/m², an optimal Mean Squared Error (MSE) of 238.16, 1129.5, 1039.9, and 1520.7 W²/m⁴, and a variance of 216.40, 1099.3, 1015.4, and 1460 for the respective seasons. These results strongly indicate the Kasten model's suitability for the climatic conditions of the studied site in Morocco, showcasing high correlation coefficients and low prediction errors. The findings underscore the Kasten model as the most fitting choice for optimizing active daylighting technology in Morocco's climate.