UV Vis NIR Research Articles

The Modeling of Concentrators for Solar Photovoltaic Systems

Concentrating photovoltaic (CPV) systems have emerged as a transformative technology that incorporates radiation concentrators into the photovoltaic system to enable radiation to be concentrated onto a receiver—the solar cells. Different concentrator configurations have different impacts on the performance of the solar photovoltaic system. This research work aims to analyze the impact of different concentrators, comparing and identifying the most efficient structures for capturing and concentrating solar energy. Aiming at a deep analysis and comparison among concentrators shapes, this research work presents a unique investigation and revision among different structures such as flat, triangular, LFR, and parabolic concentrators. Moreover, since, in the UV–visible–NIR region, metals’ reflectance varies with the incident wavelength, five metals were considered: aluminum, gold, platinum, copper, and silver. Additionally, the research focuses on studying the effects of parameters critical to the quality of the concentration on the power obtained and on the uniformity of the radiation distribution on the surface of the receiver, as well as on the number of solar rays that reach the receiver. The power on the receiver increases proportionally with the number of reflector concentrators in the system and their reflectance. For parabolic geometries, the optical efficiency is affected by the receiver’s shadow on the concentrator and, in the case of the LFR, by a non-ideal alignment of the reflectors in relation to the receiver. However, in parabolic concentrator geometries, uniformity is usually lower, since in these configurations, the radiation is focused on specific areas of the receiver, usually the central zone.

Structural, optical analysis, stress-strain, and dielectric properties of selenium oxide/LaFeO3/blend nanocomposites with tunable properties for optoelectronics and micro-supercapacitors

This work focuses on developing flexible nanocomposites by introducing two types of ceramic nanofillers into a biopolymeric blend for optoelectronic and energy-storing applications. Selenium oxide (SeO2) nanoparticles (NPs) and LaFeO3 NPs were prepared by hydrothermal and solid-state reactions, respectively, and incorporated into the polyvinyl alcohol/polyvinyl pyrrolidone (PVA/PVP) through the solution casting process. Transmission electron microscope and X-ray diffraction tests revealed the creation of hexagonal SeO2 and orthorhombic LaFeO3 NPs, with average sizes of 17 and 93 nm. The blend's degree of crystallinity was dependent on SeO2 NPs and LaFeO3 contents. The infrared absorption spectra revealed the interactions/complexation of the fillers with the blend reactive groups. The scan e-microscope (field emission mode) investigated the films' surface morphology and detected the elements they contain. LaFeO3/SeO2 content impacted stress-strain behavior, raised the tensile strength from 64 to 70.9 MPa, and dramatically lowered the strain at break and toughness. UV–vis-NIR measurements exhibited that the transmittance, extinction coefficient, and refractive index can be tuned by SeO2 and LaFeO3/SeO2 content. The direct (Eg.d)/indirect (Eg.id) band gaps were reduced from 5.25/4.9 eV to 4.95/4.7 eV. The dielectric parameters (constant, loss, energy density, and conductivity) were significantly increased after loading 5.0 wt% LaFeO3/SeO2. The dielectric moduli and Cole-Cole plots were also investigated. The structural modifications and enhancement of the optical features and dielectric parameters make the resulted samples the best candidates for optoelectronic devices and energy-storing applications such as sensors and supercapacitors.

Defects induced SnOx-TiO2 nanocomposite thin films for improved visible light driven photocatalysis and photoelectrochemical applications

Advanced oxidative removal of organic pollutants from water bodies using nanoparticles of metal oxide photocatalysts is a concurrent hot topic. In the present study, SnOx-TiO2 heterogeneous nanocomposite thin film photocatalysts have been synthesized using SnO and TiO2 precursors by binder-free doctor blade technique. X-ray diffraction was used to confirm the presence of anatase TiO2 as a major phase at elevated temperatures. Raman spectra analysis confirmed phase transformation and defect induction. X-ray photoelectron spectroscopy was utilized to determine the purity and chemical condition of the synthesized thin films. The porous nature of the thin film surface was observed using field emission scanning electron microscopy. UV–Vis-NIR spectroscopy results showed a reduction of bandgap from 3 eV to 2.6 eV with enhanced light absorption. The superior oxygen evolution reaction, redox nature and charge carrier generation were demonstrated using photo-electrochemical techniques. Improved photoresponse of the photocatalysts was observed using chrono-amperometry technique. The superior visible light-driven photocatalytic activity of the samples was demonstrated utilizing cationic and anionic model pollutant dyes. The reusability of the catalyst is ensured through successive photodecomposition processes. These results show a facile fabrication of defects induced heterogenous nanocomposite photocatalyst thin films with improved visible light activity.

Optical properties of NiO films: Effect of nitrogen-doping, substrate temperature and band gap estimation using machine learning

In this study, nickel oxide (NiO) thin films were synthesized on glass substrates using RF magnetron sputtering with varying nitrogen (N) doping ratio and substrate temperatures to explore modifications in their structural, morphological, and optical properties. The films were prepared using a high-purity NiO target under controlled sputtering conditions. Structural analysis by X-ray diffraction revealed an improvement in crystallinity in the (200) direction with increasing N ratio. In contrast, higher N ratio led to the suppression of (111) and (220) peaks, indicating a significant influence of N on the crystal structure and orientation. The films’ thickness and morphology, examined using scanning electron microscopy and energy-dispersive X-ray spectroscopy, showed uniform and homogeneous growth with smooth surface topologies. Optical properties, assessed by UV–Vis-NIR spectrophotometry, demonstrated a decrease in transmittance and a redshift in the absorption edge with increased N doping, corresponding to a narrowing of the energy bandgap from 3.7 eV to 3.45 eV. This bandgap reduction is attributed to N incorporation substituting oxygen sites, introducing defect states within the band structure. Additionally, the impact of substrate temperature on film growth enhanced crystallinity and orientation along the (111) plane at higher temperatures, with a simultaneous reduction in film thickness due to increased adatom mobility and potential thermal decomposition. The evaluation of Kernel Ridge Regression (KRR) and Ridge Regression (RR) models revealed their effectiveness in predicting band gap values for thin films at varying substrate temperatures and thicknesses. While RR excelled in predicting a band gap of 3.6 eV for a film with a substrate temperature of 24 °C and a thickness of 112.7 nm, KRR outperformed in predicting a band gap of 3.65 eV for a film with a substrate temperature of 24 °C and a thickness of 107 nm. These findings elucidate the dual influence of N doping and substrate temperature on enhancing the functional properties of NiO thin films, promising for applications in optoelectronic devices and gas sensors.

Comprehensive investigation of 2-methylquinolinium-5-sulphosalicylate monohydrate: Synthesis, characterization, multifaceted analysis of molecular structure, optical, and nonlinear optical properties

We introduce the synthesis and characterization of a novel molecular salt crystal, 2-methylquinolinium-5-sulphosalicylate monohydrate (MQSSA), obtained through an equimolar reaction between donors (D) and acceptors (A) employing crystal engineering principles. The resulting proton transfer complex, MQSSA, crystallized into a monoclinic crystal system with space group P21/C, as revealed by SCXRD analysis. Significant peaks observed in PXRD analysis confirmed the crystallinity and purity of the material. FT-IR and FT-Raman spectroscopy were employed to analyze various functional groups present in the molecule. UV–Vis-NIR spectroscopy provided insights into absorbance transmittance, lower cutoff wavelength, and optical band gap, suggesting it's suitability for diverse optical applications, while characteristic emission was identified using PL measurements. Thermal stability was assessed via TG-DTA and TG-DSC techniques. Nonlinear absorption coefficient (β), nonlinear refractive index (n2), and third-order nonlinear susceptibility (χ3) were quantified using the Z-scan technique. Hirshfeld surface analysis and fingerprint plots were utilized to gain insight into intermolecular interactions and atomic arrangements within the MQSSA crystal, emphasizing the roles of crystal structure in H...H and O...H/H...O interactions. Additionally, quantum computational methods were employed to evaluate various molecular-level electronic characteristics, including molecular orbitals, molecular electrostatic potential maps, and first and second-order nonlinear optical (NLO) polarizability, providing insights into the molecular-level NLO response properties.

Microplastic Analysis in Soil Using Ultra-High-Resolution UV–Vis–NIR Spectroscopy and Chemometric Modeling

The study of microplastics (MPs) in soils is impeded by similarities between plastic and non-plastic particles and the misidentification of MP by current analytical methods such as visual microscopic examination. Soil MPs pose serious ecological and public health risks because of their abundance, persistence, and ubiquity. Thus, reliable identification methods are badly needed for scientific study. One possible solution is UV–Vis–NIR spectroscopy, which has the ability to rapidly identify and quantify concentrations of soil microplastics. In this study, a full-range, field portable spectrometer (350–2500 nm) with ultra-high spectral resolution (1.5 nm, 3.0 nm, and 3.8 nm) identified three types of common plastics: low-density polyethylene (LDPE), polyvinyl chloride (PVC), and polypropylene (PP). Three sets of artificially MP-treated vermiculite soil samples were prepared for model prediction testing and validation: 150 samples for model calibration and 50 samples for model validation. A partial least square regression model using the spectral signatures for quantification of soil and MP mixtures was built with all three plastic polymers. Prediction R2 values of all three polymers showed promising results: polypropylene R2 = 0.943, polyvinyl chloride R2 = 0.983, and polyethylene R2 = 0.957. Our study supports previous work showing that combining ultra-high-resolution UV–Vis–NIR spectrometry with quantitative modeling can improve the accuracy and speed of MP identification and quantification in soil.

Design and fabrication of porous three‐dimensional Ag-doped reduced graphene oxide (3D Ag@rGO) composite for interfacial solar desalination

Solar-driven interfacial desalination technology has shown great promise in tackling the urgent global water scarcity crisis due to its ability to localize heat and its high solar-to-thermal energy conversion efficiency. For the realization of sustainable saline water desalination, the exploration of novel photothermal materials with higher water vapor generation and photothermal conversion efficiency is indispensable. In the current study, a novel 3D interconnected monolithic Ag-doped rGO network was synthesized for efficient photothermal application. The Ultraviolet–Visible-Near Infrared (UV–Vis-NIR) and FTIR analyses demonstrated that the controlled hydrothermal reduction of GO enabled the restoration of the conjugated sp2 bonded carbon network and the subsequent electrical and thermal conductivity through a significant reduction of oxygen-containing functional groups while maintaining the hydrophilicity of the composite photothermal material. In the solar simulated interfacial desalination study conducted using 3.5 wt.% saline water, the average surface temperatures of the 3D material increased from 27.1 to 54.7 °C in an hour, achieving an average net dark-excluded evaporation rate of 1.40 kg m−2 h−1 and a photothermal conversion efficiency of ~ 97.54% under 1 sun solar irradiance. In the outdoor real-world application test carried out, the surface temperature of the 3D solar evaporator reached up to 60 °C and achieved a net water evaporation rate of 1.50 kg m−2 h−1 under actual solar irradiation. The 3D interwoven porous hierarchical evaporator displayed no salt precipitation over the 54-h period monitored, demonstrating the promising salt rejection and real-world application potential for efficient desalination of saline water.

Newly developed CeO2 and Gd2O3-reinforced borosilicate glasses from municipal waste ash and their optical, structural, and gamma-ray shielding properties

From the useless municipal solid waste (MSW) ashes, CeO2, Gd2O3 and CeO2 + Gd2O3 doped borosilicate glasses were organized via melting-quenching procedure. Various optical, structural, physical and radiation shielding parameters were examined towards the influence of 100 kGy of γ-radiation. UV–visible NIR spectra revealed UV peaks at 351, 348 and 370 nm corresponding to the trivalent states of Ce3+ and Gd3+ ions, while, photoluminescence (PL) spectra displayed asymmetric broad excitations of Ce3+ and Gd3+ ions due to 4f → 5d transitions, and emission intense bands at 412, 434, and 417 nm. CIE chromaticity shows that Gd3+ ions increase the luminescence of Ce3+. FTIR absorption bands revealed an overlapping between tetrahedral groups of silicate (SiO4), with trigonal (BO3) and tetrahedral (BO4) units of borate. The influence of 100 kGy obtains quite reduction in UV–visible NIR and PL peaks, large stability in FTIR and ESR spectra, and stability of thermal expansion coefficient (CTE) as well. The whole data revealed optical, structural and physical stability of glasses after irradiation besides an enhancement in microhardness owing to more structural compactness and high bonding connectivity. Radiation shielding parameters from Phy-X/PSD program showed higher values of mass (MAC) and linear attenuation coefficients (LAC), and effective atomic number (Zeff) in the order of; glass Ce+Gd > glass Ce > glass Gd. Ce + Gd doped glass revealed also the lowest half value layer (HVL) comparing to other shielding commercial concretes. The study recommends the beneficial and economical use of the useless MSW ash to produce CeO2 and/or Gd2O3 borosilicate glasses with hopeful radiation shielding features.

Formula process and coloring mechanism of bluish‐white porcelains from the Lanxi kiln in Fujian, China

AbstractBluish‐white porcelain was a prominent type of porcelain in ancient China, renowned for its distinctive artistic style and unique characteristics. The Lanxi kiln in Jianning County, Fujian Province, has unearthed a multitude of bluish‐white porcelain products from the Southern Song dynasty that exhibit vibrant glaze color and exceptional craftsmanship. The quality of these porcelains surpasses that of contemporaneous Jingdezhen and Baishe kiln products in Jiangxi Province, representing the pinnacle of bluish‐white porcelain excavated across various regions of China during the Southern Song dynasty. In this study, samples of bluish‐white porcelain from the Lanxi kiln and Baishe kiln, dating back to the Southern Song dynasty, were selected and analyzed via energy dispersive X‐ray fluorescence, ultraviolet–visible–near infrared (UV–Vis–NIR) spectrophotometer, metallographic microscopy, and scanning electron microscopy with EDS to investigate their glaze formula process and coloring mechanism. Moreover, these findings were subsequently compared with those of Jingdezhen bluish‐white porcelain from the same period. The results demonstrate that the raw materials of porcelain stones used in the glaze of the Lanxi and Jingdezhen kiln are similar in composition yet differ significantly from that employed in the Baishe kiln. Potassium feldspar was added to the glazes of the Baishe and Lanxi kiln, potentially existing exchanges of process of the two kilns due to their geographic proximity. The firing atmosphere of bluish‐white porcelain with different glaze colors in the same kiln exhibits significant variations. In particular, the lake blue sample undergoes firing under a strong reducing atmosphere, resulting in an excess content of Fe2+ in octahedral hexagon coordination within the glaze, thereby intensifying its blue hue. The colors of various glazes are determined by both chemical color and physical color. The former is a result of the absorption of Fe3+ in the ultraviolet region and the d‐d electron orbital transition of Fe2+ in the infrared region. However, the latter is not the scattering physical color but the diffuse reflection physical color produced by bubbles and anorthite crystallization layers.

Copper-doped zinc tartrate (Cu-ZnT) nanocrystals: Exploring their physical and antimicrobial properties

This study investigates the growth and properties of pure zinc tartrate (ZnT) and copper-doped zinc tartrate (Cu-ZnT) nanocrystals synthesized via a sol-gel technique using double-distilled water, sodium metasilicate, and tartaric acid. Controlled pH gels were prepared with the subsequent addition of zinc chloride and copper chloride solutions to facilitate nanocrystal formation. The synthesized nanocrystals were characterized using various techniques, including Energy-Dispersive X-ray analysis, Fourier Transform Infrared Spectroscopy, Thermogravimetric analysis, UV–visible-near infrared spectral analysis, X-ray diffraction (XRD), and Field Emission Scanning Electron Microscopy. EDAX confirmed the elemental composition of Zn, Cu, C, and O in the crystals. FTIR spectra revealed the presence of functional groups corresponding to water of crystallization, tartaric acid moieties, and potentially other compounds. TGA analysis indicated a two-stage decomposition process for ZnT and the formation of zinc copper oxide in Cu-ZnT. UV–vis-NIR analysis yielded a low cut-off wavelength of 285 nm for both crystals, suggesting electronic transitions below 350 nm. Both ZnT and Cu-ZnT nanocrystals are transparent in visible and near-infrared light, absorbing strongly in the ultraviolet. Copper doping enhances Cu-ZnT light absorption. While both act as insulators, Cu-ZnT exhibits significantly higher conductivity due to copper doping. XRD analysis estimated an average crystalline size of 42 nm, while FE-SEM images revealed a quasi-spherical morphology. Refractive index, extinction coefficient, and optical bandgap were further determined, highlighting the potential suitability of these nanocrystals for optoelectronic applications. Antibacterial and antifungal assays demonstrated moderate effectiveness against tested microorganisms compared to standard drugs.

Study of deposition temperature effect on spray-deposited copper oxide thin films and its schottky diodes

Due to its ideal optical and electrical properties for upcoming electronic devices, Cu2O is commonly regarded as one of the most promising p-type oxides. Copper (Cu) rapidly deposits mixed phases of its oxides. This article describes the spray deposition method for developing copper oxide thin films at temperatures between 200 and 400 °C on glass substrates coated with ITO. Through optimization of the deposition temperature, Cu2O-rich phases were attained in the copper oxide films, typically around 300 °C. A Cu-rich phase was seen at 200 °C deposition temperature, and this phase progressively diminished at higher temperatures. At 400 °C, the CuO phase began to enrich the films in the meantime. Analysis using an x-ray diffraction (XRD) verified the existence of Cu2O phases (111), (200), and (220). The crystallites were discovered to be between 17.49 and 20.32 nm in size for the films deposited between 300 and 400 °C. The x-ray Photoelectron Spectroscopy (XPS) identifies Cu and oxygen as the main components. Furthermore, it is demonstrated that the deposition temperature significantly affects the copper’s oxidation state. The Atomic Force Microscopy (AFM) investigation showed that as the temperature increased, surface roughness decreased. As the deposition temperature increased, the energy band gap of the deposited films widened from 1.67 to 2.85 eV, as observed by the UV–vis-NIR spectrophotometer. Moreover, the fabrication of Schottky diodes with Cu metal contacts is also reported. These fabricated diodes showed a proportionate rise in barrier height with increasing deposition temperature.

One-pot solvothermal route to stannite-like Cu2CoSnS4 microspheres as pseudocapacitive material for electrochemical energy storage

This study explores the potential of stannite-like Cu2CoSnS4 (CCTS) microspheres for electrochemical energy storage applications. To fabricate Cu2CoSnS4, a facile solvothermal route was employed using ethylene glycol (EG) as the solvent and polyvinyl pyrrolidone (PVP) as the capping and structure-directing agent. Thorough characterization techniques, including X-ray diffraction, Raman spectroscopy, energy-dispersive X-ray analysis, and electron microscopy were employed to investigate the crystallinity, morphology, lattice structure, and growth mechanism of CCTS microspheres. UV–vis–NIR spectroscopy revealed that the material exhibits absorption in the visible and near-infrared range, with an optimal bandgap of 1.4 eV, suggesting potential applications in photovoltaics. We also analyzed the disordered stannite structure by a combined study of Raman spectroscopy and elemental analysis. Furthermore, the prepared CCTS microspheres were tested as active materials of supercapacitor electrodes, and the results showed promising electrochemical performance with a specific capacitance of 1700 F g−1 at 5 mV s−1, which is close to 70 % of the theoretical specific capacitance of Cu2CoSnS4. The electrode maintained 80.2 % capacitance retention and a Coulombic efficiency of 99.8 % after 500 cycles. This research highlights CCTS microspheres as promising candidates for energy harvesting and storage applications.

A new organic compound (C9H12N2O2): Crystal structure, characterization, Hirshfeld surface analysis, electronic properties, NLO properties, DFT calculation and molecular docking

A crystal of the organic chromophore N-propyl-4-nitroaniline was synthesized via the process of gradual solvent evaporation. The parameter values of the cell were calculated using single-crystal X-ray diffraction. In order to learn more about the band gap energy and optical quality, a UV–Vis–NIR spectral study was carried out. The lower cut-off wavelength is shown to be as low as 233 nm, and the direct optical band gap is determined to be 4.89 eV. This study delves into the intricate interplay between solvent polarity and the electronic properties of the titled compound, employing TD-DFT calculations. Notably, the analysis unveils a nonlinear correlation between solvent polarity and absorption wavelength, with an observed red-shift of up to 22 nm in select polar solvents. Furthermore, a distinct trend emerges in the variation of the energy gap between HOMO and LUMO, revealing a solvent-specific impact ranging from 0.279 eV to 0.378 eV. These findings offer a nuanced understanding of how solvent environments intricately modulate electronic behavior. Using FTIR spectrum analysis, the frequencies of the vibrations were determined. The Kurtz-Perry powder method verified the existence of Second Harmonic Generation (SHG). At the B3LYP/6–311++G (d, p) level of theory, DFT was also used to look at the crystal molecular structure geometry, charge transfer interactions between molecules, thermodynamic properties and hyperpolarizability.

Exploring the influence of iron doping on structural, morphological and optical properties of chemical bath deposited cadmium selenide thin films for optoelectronic applications

This research investigates the structural, morphological, and optical properties of Cadmium Selenide (CdSe) thin films deposited via the Chemical Bath Deposition (CBD) Technique, focusing on the impact of Iron (Fe) doping. Using Cadmium Chloride (CdCl2) and Ferrous chloride (FeCl2) as precursor materials, the research investigates how Fe doping affects the structural and photoelectric characteristics of the films. Employing various characterization methods including X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier-Transform Infrared Spectroscopy (FTIR), and UV–Vis NIR spectroscopy, the study provides a comprehensive analysis of the films. XRD analysis confirms the formation of a cubic structure with a predominant orientation along the (111) plane, consistent with XRD peaks. Additionally, XRD data reveals the degradation of thin films post-annealing. Crystalline size and strain are determined using the Debye-Scherrer and Wilson formulae, while lattice constant and Size-strain plots are derived from X-ray line broadening. The average crystallite size ranges from 12 to 21 nm. Optical band gaps are found to be 2.25 eV, 2.91 eV, 2.87 eV, and 2.85 eV for the samples. Interestingly, a decrease in crystal size with increasing doping concentration correlates with a reduction in bandgap. This investigation offers valuable insights into the fabrication and characterization of CdSe thin films, particularly highlighting the impact of Fe doping on their structural and optical properties. Overall, this study provides valuable insights into the fabrication and characterization of CdSe thin films, emphasizing the importance of precise doping control for tailoring material properties and advancing their applications in photovoltaic and optoelectronic devices.

Comments on “Investigations on growth, XRD, strain, FTIR, UV–Vis NIR, photoluminescence, SHG, and z-scan analyses of l-cysteine picrate single crystal for NLO and optical limiting applications”

Alexandar et al. (Inorg. Chem. Commun. 159 (2024) 111751) report to have grown “l-cysteine picrate” crystal (LCP) by evaporation of an aqueous solution containing equimolar ratios of l-cysteine and picric acid at 40 °C in a constant temperature bath. A critical analysis of the reported infrared spectral and X-ray powder data, reveals that the LCP crystal is, in fact, picric acid. Previously, Alexandar et al. has claimed to have grown a so-called “l-methioninium picrate” crystal (LMP) (J. Nonlinear Opt. Phys. Mater. 25 (2016) 1650052) which is also improperly characterized as it is devoid of any picrate and LMP is indeed l-methionine. Taking as examples LCP, LMP and the supposedly new crystals “l-methionine succinic acid” (Chem. Phys. Impact 6 (2023) 100203) and “(4-nitrophenyl) methionine” (Indian J. Phys. 97 (2023) 3835) which are, in fact, succinic acid and l-methionine, respectively, we highlight a combined use of infrared spectra and X-ray diffraction data for accurate characterization of known crystals.

Influence of graphitic phase on the structural, optical, electrical and photocatalytic properties of BiFeO3/KNbO3 based binary nanocomposites

Synthesis of ternary nanocomposites of BiFeO3-Graphene-KNbO3 through simple solution method has been made at various concentrations of graphene ranging 0.025–0.1 % mole fraction. The obtained nanocomposite powders with varying content of graphitic phase were subjected to different characterization techniques such as XRD, Raman, SEM/EDX/Elemental mapping, HR-TEM, UV–Vis–NIR spectroscopy, dielectric and photodegradation measurements. All above studies have provided the collective impression of the existence of all entities in the prepared ternary composites. Dielectric studies revealed that progressive loading of graphene content led to the increased pathway for the conduction of electrons in the sample. However, the loading of graphene at appropriate concentration has brought out increased dye degradation capacity of BiFeO3-Graphene-KNbO3 ternary nanocomposites towards methylene blue dye. The results obtained from various studies have been discussed in detail.

Synthesis of transparent tin-doped indium oxide (ITO)-containing glass-ceramic coating by the sol-gel route for UV/NIR-shielding

Transparent glass-ceramic containing tin-doped indium oxide nano-crystalline phase was synthesized using the sol-gel method. The prepared sol, which was based on sodium aluminoborosilicate glass composition, was applied on soda-lime-silicate glass substrate through the dip-coating technique. Developing such glass-ceramics can offer several advantages, including reducing the total cost of production, enhanced chemical durability and a low-temperature synthesis process. The thermal behavior of the dried gels was investigated using simultaneous thermal analysis (STA), to determine the decomposition temperature of the nitrate salts in the gel, its glass crystallization temperature, and finally to optimize the heat treatment regime and optical properties as well. UV–Vis–NIR spectroscopy of the coated samples after heat treatment at 500 °C for 10 h revealed high visible transparency (T>70%) while indicating significant UV/NIR shielding, i.e. near zero and 10 % transmission, respectively. Phase analysis and crystallization behavior studies were conducted using XRD and FE-SEM to evaluate the morphology and size of the precipitated crystallites. According to the results, the optimum heating program for ITO crystallization was heating temperature and soaking time of 500 °C and 10 h, respectively. The undesirable crystalline phase of InBO3 was precipitated as the main crystalline phase by increasing the heat treating temperature to 550 °C. Furthermore, the glass structure was studied using FTIR spectroscopy demonstrating a highly polymerized glassy network for the coating. The effect of the precursors-to-solvent ratio during the synthesis process on the final optical properties was also investigated.

Self-powered stable high-performance UV–Vis–NIR broadband photodetector based on PVP-Cobalt@Carbon nanofibers/n-GaAs heterojunction

The self-powered PVP-Co@C nanofibers/n-GaAs heterojunction photodetector (HJPD) was fabricated by electrospinning of the nanofibers onto GaAs. An excellent rectification ratio of 6.60 × 106 was obtained from I–V measurements of the device in the dark. The I–V measurements of the fabricated device under 365 nm, 395 nm and 850 nm lights, as well as I–V measurements in visible light depending on the light intensity, were performed. The HJPD demonstrated excellent photodetection performance in terms of a good responsivity of ∼225 mA W−1 (at −1.72 V) and at zero bias, an impressive detectivity of 6.28 × 1012 Jones, and a high on/off ratio of 8.38 × 105, all at 365 nm wavelength. In addition, the maximum external quantum efficiency and NPDR values were 3495% (V = −1.72 V) and 2.60 × 1010 W−1 (V = 0.0 V), respectively, while the minimum NEP value was ∼10−14 W.Hz−1/2 for 365 nm at V = 0.V volts. The HJPD also exhibited good long-term stability in air after 30 d without any encapsulation.

Influence of Co-formers on the radiation shielding properties of zinc incorporated barium borate glasses for radioactive waste storage applications

The primary objective of the current investigation is to explore a novel series of Dy3+ions doped Zinc incorporated barium borate glasses synthesized through the classic melt quenching approach for the application of radiation defending. In this examination, the co-formers TeO2, Bi2O3, V2O5 and one of the glass formers P2O5comprised individually with the glass network. The non-crystalline phase of fabricated glasses symbolized by the empirical formula (64−x) B2O3+xA+15BaO+20ZnF2+1Dy2O3 (where x = 0, 20; A = P2O5, TeO2, Bi2O3, V2O5) and these pristine glasses were characterized by various techniques. Structural investigations were done by XRD, FTIR approach. FTIR analysis reveals the existence of functional group and their corresponding band assignments in the glass samples were recognized. The UV–Visible–NIR absorption spectra elucidates the optical properties including the energy transitions concerned with the trivalent Dysprosium ion, Urbach energy, direct and indirect bandgap energy using Tauc's plot method. The vanadium pentoxide (V2O5) co-former comprised glass network exhibits highly contrary behavior in optical scrutiny compared to other glasses. The Physical, structural attributes along with elastic properties are deliberated for the prepared glasses. The ionicity and covalency estimation validates the fact that the present glass samples exhibit maximum ionic nature. Radiation shielding parameters such as mass attenuation coefficients (MAC), half value layer (HVL) and effective atomic number (Zeff) for the titled glasses have been enumerated, discussed and reported. Among the prepared glasses, Bi2O3 co-former comprised glass exhibit better efficiency than the available concrete shielding materials.

Formation of skyrmion phase in the Fe–Co–Si system by mechanochemical activation

Fe, Co and Si powders were exposed to mechanochemical activation by high-energy ball milling for 0, 2, 4, 8 and 12 h. The samples were subsequently characterized by Mössbauer spectroscopy, X-ray powder diffraction (XRPD), magnetic measurements and optical diffuse reflectance spectroscopy. The room temperature Mössbauer measurements were consistent with the occurrence of FeCo2Si and Fe0.5Co0.5Si crystalline phases. The low temperature Mössbauer spectra confirmed the absence of superparamagnetism up to 44 K in the milled system. XRPD patterns supported the phase sequence derived from Mössbauer spectroscopy. The coercive field was found to increase with the ball milling time (BMT). Zero-field-cooling-field-cooling (ZFC-FC) measurements performed at 200 Oe in the temperature range 5–300 K evidenced the transition to the skyrmion phase of the Fe0.5Co0.5Si material below the critical temperature of 44 K. The optical absorption in the UV–Vis–NIR region of the spectrum was found to increase with BMT.