Direct Band Gap Energy Research Articles

Synthesis, structural, optical, thermal, Hirshfeld surface analysis and antibacterial investigations of bis(2-aminobenzothiazolium) tetrabromozincate (II) monohydrate

Bis(2-aminobenzothiazolium) tetrabromozincate (II) monohydrate crystal were produced by the slow evaporation of solution technique (SEST) at room temperature and their triclinic structure was determined using single-crystal X-ray diffraction (XRD). FT-IR spectrum analysis revealed the existence of a protonated NH group with symmetric stretching frequency. In UV-DRS, direct band gap energy was determined using the Kubelka–Munk algorithm. The absorption is primarily due to the transitions within the organic part of the hybrid and charge transfer. The compound exhibit solid-state fluorescence at room temperature consistent with photoluminescence investigation. The thermal stability of the compound indicates that the process was exothermic. The CSM calculation of ZnX42- (X=Br) closely aligns with the ideal tetrahedral geometry of the anions. Hirshfeld surface analysis which is obtained from single-crystal XRD data is used to investigate the intermolecular interactions and crystal packing and exposes stronger contacts associated with strong interactions. The antibacterial studies of the investigated compound was comprehensively examined against pathogens including Enterococcus faecalis, Streptococcus pyogenes, Pseudomonas aeruginosa and Proteus mirabilis by using agar well diffusion method. The results indicate significant efficacy in inhibiting bacterial growth for the compound.

Insight into deposition duration-varied crystallinity, optical parameters, morphology and electrical properties of solution-processed nanostructured CdSSe thin films

Nanostructured cadmium sulpho selenide (CdSSe) films have been grown onto glass substrates for different deposition durations via a facile solution-based method known as chemical bath deposition (CBD). XRD studies revealed that the crystallites in the films possessed hexagonal (wurtzite) structures with predominant orientation along the (002) plane. The crystallite size increased from ∼5.95 nm to ∼16.69 nm with the increase in deposition duration from 1 h to 4 h. The absorbance, transmittance and reflectance measurements were carried out. A transparency of ∼(50–80) % was obtained for the films. The direct optical energy band gap was found to decrease from 1.982 eV to 1.952 eV with the increment of deposition duration from 1 h to 4 h. SEM micrographs of the films revealed the presence of nano spherical-shaped grains with an average size ranging from ∼305 nm to ∼612 nm. HRTEM images illustrated the presence of compact nano-spherical grains and nano-crystallites distributed in random orientations. Raman spectroscopy divulged the presence of CdSe and CdS vibrational Raman modes and overtones in the films. PL spectra revealed a prominent red emission band along with weak luminescent bands in the yellow-red emission region. The presence of Cd–Se and Cd–S bonds in the films was validated using FTIR analysis. Electrical investigation revealed the linear current‒voltage relationship for the films with the rise in conductivity with deposition duration. Hence, deposition duration stands out as a vital parameter for modulating the properties of CdSSe thin films for use in photovoltaic devices and optoelectronics.

Green synthesis of zinc oxide nanoparticles using Terminalia arjuna bark extract: structural, optical and photocatalytic study

Abstract Zinc oxide (ZnO) nanoparticles have been successfully synthesized by using Terminalia arjuna bark extract via a green route. Structural analysis using X-ray diffraction confirmed the prepared samples are crystalline having hexagonal wurtzite structure with space group P63 mc and average crystallite size is found to be 8.93 nm. Rietveld refinement of the data was carried out using Material Analysis Using Diffraction (MAUD) software and reliability parameters of the refinement have been obtained. Optical properties of the sample investigated by ultraviolet – visible diffuse reflectance spectroscopy reveal an absorption peak to lie at 348 nm and the direct optical band gap energy using Kubelka–Munk function is found to be 3.20 eV. Morphological investigation using scanning electron microscopy revealed that ZnO nanoparticles are nearly spherical and agglomerated. Energy-dispersive X-ray spectrometry analysis showed the presence of Zn and O only. Transmission electron microscopy imaging confirmed the predominant hexagonal structure of the prepared nanoparticles having average particles size of 9.66 nm, which is in agreement with the X-ray diffraction result. Fourier transform infrared spectroscopy was used to identify the functional groups and different vibrational modes present in the sample. The photocatalytic activity of the prepared ZnO nanoparticles was studied using methylene blue (MB) dye under a single wavelength UV light source (λ = 254 nm). The degree of degradation of MB solution was about 56 % within 120 min of illumination to UV light and the degradation reaction follows first order kinetics with rate constant 0.00434 min−1.

The pH-dependent properties of cuprous oxide thin films prepared by electrochemical deposition for liquid petroleum gas sensing

Efficient liquid petroleum gas sensing was investigated by modulating the pH level (8, 9, 10, 11, and 12) of electrochemically deposited nanostructured cuprous oxide thin films in a lactate bath. The synthesized films were characterized by surface contact angle, XRD, SEM, UV–Vis absorption, Mott-Schottky, and AC impedance spectroscopy measurements. These displayed a unique initial increment or decrease followed by a persistent decrement or increment at pH 9–10. This turning pH point exhibited the least wetting polycrystalline Cu2O growth with the smallest crystallite size of ∼ 45 nm, the highest dislocation density of ∼50 µm−2, and a strain of 0.03 according to X-ray diffraction. SEM micrographs identified ∼ 1 µm-sized, closely structured grains with trigonal-prismatic shapes. The Mott-Schottky plots drawn from C-V measurements revealed a significant dependence of flat band potential and free carrier density on the deposition bath pH level. Cu2O films deposited using the lactate bath changed the conductivity at pH 9 from n-type to p-type when increasing the pH value. With the conductivity transition, films prepared at pH 9 displayed a relatively high direct band gap energy of 2.28 eV. Liquid petroleum gas (LPG) sensing at 70 °C demonstrated the most substantial gas response of 11.5 % at pH 10 Cu2O films. Cu2O thin films deposited at pH 9 emerged as the most stable and reproducible p-Cu2O LPG sensor, with response and recovery times ranging from 20 to 25 seconds. Remarkable changes in the film structures and morphologies were revealed with pH values above 9 after the gas exposure. The grain shape and distribution of pH 9 remained unchanged, assuring the stability of the sensing platform.

Green photoluminescence, supercapacitor and cytotoxic properties of nickel doped haematite nanoparticles

Fe2O3: Ni (1–9 mol.%) nanoparticles (NPs) were synthesized using the co-precipitation method and calcined at 500∘C for 12 h. The crystallite size, phase, crystallinity, and structural parameters were analyzed via powder X-ray diffraction. The Bragg reflections confirmed that the synthesized NPs crystallize in a pure hexagonal crystal structure with space group R-3c. Surface morphology analysis revealed agglomerated NPs of irregular sizes and shapes. Energy Dispersive X-ray Analysis confirmed the presence of Fe, O, and Ni elements, as well as the purity of the sample. Both the direct band gap energy and crystallite size decreased with increasing dopant concentration. Detailed studies were conducted on the photoluminescence and anticancer properties. The CIE coordinates indicated a color tuning from blue to green in the visible region. CIE coordinates and CCT values ranging between 2860 to 9547 k demonstrated that the synthesized nanophosphor material meets the requirements of display technology. Additionally, anticancer properties were investigated using HeLa cells and compared with the standard drug cisplatin for biomedical applications. Electrochemical investigations revealed super capacitance values ranging from 93.43 to 149.13 F/g at a scan rate of 10 mV/s with increasing Ni2+ concentration. Therefore, the synthesized Ni2+-doped hematite NPs show great promise in display technology, the biomedical field, and as supercapacitors in energy storage devices.

Exploring the physical properties of novel double perovskites A2InAsO6 (A=Sr, Ba) for renewable energy applications: Ab-initio calculations

Nowadays, double perovskites for renewable energy are emerging materials because of their interesting properties such as simple and stable crystal structure. In our study, we theoretically explored the optoelectronic along with mechanical and thermoelectric characteristics of A2InAsO6 (A = Sr, Ba) using density functional theory and semi-classical Boltzmann theory followed by WIEN2k code. The thermodynamic and structural stabilities are determined based on the cohesive energy, enthalpy of formation and tolerance factor. The ductile and brittle behaviour has been checked by Pugh's ratios. The measured values of narrow direct energy band gaps are 0.70 eV for Sr2InAsO6, and 0.18 eV for Ba2InAsO6 with TB-mBJ approximation. These compositions are potentially used in optoelectronic applications because their electronic characteristics are tuneable. In the energy range 0–12 eV, the compositions under consideration exhibit a single-peaked response while the replacement of cation Sr with Ba caused a shift in optical structures towards lower energies. These compositions are also suitable for thermoelectric systems as they possess high values of the figure of merits at room temperature and the measured values 0.049 eV for Sr2InAsO6, and 0.10 eV for Ba2InSbO6 are recorded.

Unveiling Novel Direct Bandgap Allotropes of Germanium: A Computational Exploration

Germanium crystallizes in a cubic diamond structure, which restricts its applications in optoelectronics due to its indirect band gap. However, the slight energy difference between the direct and indirect band gaps in germanium presents a promising opportunity to engineer its structure into a direct band gap material, with the hexagonal diamond (lonsdaleite) phase being a notable example. In this study, we conducted an extensive computational search to find germanium allotropes with a direct band gap and low energy using a sensible random structure search approach informed by data-derived interatomic potentials. Among the predicted allotropes, we identified a hexagonal 8H structure with the lowest energy compared to all known germanium allotropes and only 5 meV/atom above the ground state cubic diamond structure. Compared to the cubic diamond phase, which has complete cubicity, the 8H phase consists of 3/4 cubicity and 1/4 hexagonality. This structural motif, coupled with band structure back folding in the hexagonal Brillouin zone, results in a direct band gap of 0.25 eV. Given the prior experimental discovery of 2H and 4H polytypes, the experimental synthesis of the 8H allotrope in germanium is highly feasible. Future research could explore alloying 8H germanium with silicon to optimize the bandgap energy and optical transitions, potentially achieving lifetimes comparable to those of group III-V semiconductors like GaAs.

Photoluminescence, cytotoxic and oxygen evolution reaction kinetics studies of silver doped haematite nanoparticles

Fe2O3: Ag(1–9 mol %) nanoparticles (NPs) have been synthesized through the co-precipitation method. Crystallite size, phase, crystallinity, and structural parameters were analyzed by using powder X-ray diffraction. The Bragg reflections confirm that the synthesized NPs crystallize in hexagonal crystal structure with space group R-3c. Surface morphology consists of agglomerated irregular size and roughly spherical-shaped NPs. Energy Dispersive Analysis of X-ray confirms the presence of Fe, O, and Ag elements and also the purity of the sample. Crystallite size decreased with the increase in dopant concentration. Direct band gap energy is found to increase with an increase in dopant concentration. Photoluminescence and anticancer properties were studied in detail. The CIE coordinates confirm red emission in the visible region. CIE and CCT co-ordinate values indicate cool light emission, hence, the synthesized nanophosphor material meets the demand of display technology. Further anticancer properties were investigated on HeLa cells and compared with the standard drug cisplatin for biomedical applications. Further, Oxygen evolution reaction kinetics was investigated for Fe2O3:Ag (1 mol %) nanoparticles. demonstrates enhanced oxygen evolution reaction performance with a low overpotential of 348 mV, as shown by linear sweep voltammetry. It also exhibits a favorable Tafel slope of 83 mV/dec, indicating efficient electron transfer kinetics, making it a promising candidate for OER applications.

Biogenic synthesis of CeO2 nanoparticles via moringa oleifera seed extract: Photocatalytic and biological activity for textile dye degradation

This article presents a study on synthesizing cerium oxide nanoparticles utilizing cerium nitrate and Moringa oleifera seed extract as stabilizing and reducing agents. The XRD pattern of cerium oxide was a cubic structure with an average crystalline size of 11.92 nm. The surface feature of ceria nanoparticles has a foam-like nanostructure, type IV isotherms-mesoporous, with a 56.845 m2/g specific surface area. The UV–Vis absorbance and Tauc plot showed that the direct and indirect energy bandgap was 2.51 and 2.79 eV, respectively. TGA/DTA has established structural phase stability with corresponding mass changes by influencing bioactive molecules of seed extract in cerium nanoparticles. These nanoparticles exhibited effective antibacterial properties against S. aureus and E. coli pathogens, and the turbidimetry antioxidant properties were evaluated. Dye degradation through the photocatalyst was investigated, with the optimum degradation efficiency of 99.71 and 99.83 %, pseudo-first-order kinetics 4.62 × 10−2 and 5.07 × 10−2, respectively, for anionic-Congo red and cationic-Malachite green dye. The observed results concluded that green-mediated nanostructured ceria particles might effectively be used for antibacterial and photocatalytic purposes.

Dielectric, thermal and optical properties of PVDF-based (LaFeO3)0.5 (BaTiO3)0.5 perovskite composite films for advanced technological applications

(1-x)PVDF/(x)LFO-BTO composite films with weight percentages (x = 0, 0.05, 0.1 and 0.15) were prepared by solution casting method. Phase identification was carried out using the X-ray diffraction (XRD) technique revealing different phases (α, β & γ) of PVDF. FTIR results confirmed the presence of different vibrational modes and phases including PVDF phases. AFM and SEM were used to investigate the surface & morphological analysis, the results showed that the surface roughness increased with the concentration of LFO-BTO into PVDF films. From optical absorption spectra, the direct band gap and indirect band gap energies of the PVDF/LFO-BTO were evaluated by incorporating Tauc's relation. The composites experienced a reduction in band gap upon the addition of 0 - 15 wt% of LFO-BTO with an increasing trend in Urbach's energy. The dielectric investigations revealed elevated dielectric constant values across all composites at lower frequency ranges, attributed to interfacial polarization. Specifically, the dielectric constant of 15 % wt of LFO-BTO was found to be much higher (6 times more than the pristine PVDF). Additionally, the dielectric loss was suppressed with increasing filler concentration within the frequency range of 1 KHz to 1 MHz. Impedance spectroscopy analysis depicted a distinctive semi-circular pattern that was linked to the underlying conduction mechanism. The behaviour of ac-conductivity revealed the conduction process following the Nyquist plot. DTA-TGA analysis showed a notable improvement in thermal stability with increasing concentration in the PVDF matrix.

The interaction of light with oxygen-vacancy-rich W18O49 nanoparticles synthesized using different acid molarities for acidic and neutral water treatments

Toxic industrial compounds as a global difficulty can adversely impact people's health and the environment which motivates studies on the interaction of light and metal oxide nanoparticles to treat the water through adsorption or photocatalysis mechanism by nanoparticles. In the paper, oxygen-vacancy-rich W18O49 nanorods are successfully synthesized by a facile one-pot hydrothermal method using different molarities of hydrochloric acid (HCl) (2–12 M) as proposed candidates to treat the wastewater and solve the global difficulty related to treating the acidic water. The results declare that the change in acid molarity leads to noteworthy changes in the characteristic properties of the produced W18O49 nanorods, and the lowest acid molarity (2 M) causes the formation of uniform and pure monoclinic W18O49 nanorods with the high specific surface area (SSA) of 51.33 m2/g. Furthermore, the nanorods exhibit indirect and direct band gap energies in the range of 2.52–2.68 eV and 2.54–3.08 eV, respectively, as influenced by varying acid molarities (2–12 M). Furthermore, the impressive effects of acid molarity on the methylene blue removal efficiency of the nanorods under ultraviolet (UV) light are observed. The highest efficiency is obtained for W18O49 nanorods synthesized using the acid molarity of 2 M which can be explained by its high SSA, small band gap energy, generation of a large number of electron-hole pairs, and its efficient charge separation. The efficiencies of water treatment reach up to 99 % and 99.5 % at pH of 7 and 5, respectively, which is an excellent achievement and leads to proposing the mentioned W18O49 nanorods as an excellent candidate for treating wastewater and acid factory effluent which represents an appreciable breakthrough in addressing the issue.

Synthesis and Characterization of Cobalt-doped Titanium Dioxide Thin Films as Solar Cell Components using UV-SEM Analysis

Research has been carried out in the form of the synthesis and characterization of thin films of titanium dioxide with the addition of cobalt doping. The purpose of this research was to synthesize and characterize thin films related to optical properties, morphological shapes, and components of thin film compounds that are good for use as basic materials for the development of nanoparticle technology in the form of solar cells. The research was carried out in two stages, namely synthesis such as preparation of glass substrates, preparation of sol-gel solutions, deposition of solutions onto glass substrates, and heating of TiO2:Co thin film samples. The next stage is the thin film characterization test, where the optical properties of the thin film, such as absorbance, transmittance, gap energy, and activation energy, are measured using a UV-vis spectrophotometer, while morphological data and components of the thin layer compounds are measured using a Scanning Electron Microscope-Energy Dispersive X-rays (SEM-EDX). Based on data analysis and discussion, it was found that the optical properties, such as the transmittance value of the thin film, experienced the lowest point at a wavelength of 250–280 nm with a maximum percentage value of 62.14 to 78.85%. The greater the doping concentration, the lower the transmittance value. This condition is inversely proportional to the absorbance value of the maximum TiO2:Co thin film, which is in the region with a wavelength of 280–300 nm and a value of 5.70–6.31. The greater the doping concentration, the greater the absorbance value. The energy bandgap values of TiO2:Co thin films for doping concentrations (0, 5, 10, 15, 20)% were 3.44; 3.39; 3.38; 3.32; 3.22 eV for the direct energy bandgap and 3.86; 3.85; 3.84; 3.85; 3.82 eV for the indirect energy gap. The activation energy of the TiO2:Co thin film decreased from 2.86 to 2.26 eV. As for the morphological data of the TiO2:Co thin film, it was found that the greater the concentration of doping, the layer was deposited evenly, finely, and homogeneously. Regarding the data on the components of the thin layer compounds, it was found that the percentage of TiO2 content was in the range of 64.48–95.94%, while for Co, it was in the range of 0.00–19.21%.

Structural and optical properties of green-synthesised tricobalt tetroxide nanoparticles

In this study, we investigated the structural and optical properties of garlic extract-based green-synthesised tricobalt tetroxide nanoparticles. Transmission electron microscopy revealed a particle size range of 8–22 nm for the prepared powder sample. Powder x-ray diffraction data and Rietveld refinement results confirmed the spinel cubic crystal structure of the tricobalt tetroxide nanoparticles, with an average crystallite size of 11.23 nm. This crystal structure corresponds to the Fd3̅m space group and has an average lattice constant of 0.791 nm. The bond lengths of Co3+–O2− and Co2+–O2− are measured to be 0.188 nm and 0.190 nm, respectively. The FTIR data provided evidence of the presence of various functional bands, which helped qualitatively determine the purity of the sample. The UV–vis spectrum estimated two direct energy band gap values (3.7 eV and 2.2 eV) that may be useful for efficient interaction with a wide range of ray spectra to create more electron–hole pairs for various photo-responsive applications, such as dye degradation, solar cells, and optoelectronic components.

Effect of polypyrrole incorporation amounts on the optical and electrical properties of PVA/CMC blended polymer for optoelectronic applications

In the present work, hybrid flexible blended polymers of polypyrrole (PPy)/polyvinyl alcohol (PVA)/carboxymethyl cellulose (CMC); PVA/CMC/x wt % PPy; were constructed as promising blended materials to be used in various optoelectronics applications. X-ray diffraction and scanning electron microscopy techniques were used to investigate the structure and the surface morphology of polymer nanocomposites. The doped blends have better absorption of the three types of ultraviolet (UVA, UVB, and UVC), as well as the visible spectrum. The transmittance values in the visible range dropped from 90 % to 63 % as the PPy concentration reached 0.5 wt%. At x = 0.5, the minimum direct and indirect optical band gap energy values of (4.82, 4.39, 4.23) eV and (3.76, 3.84, 3.62, 2.93) eV, respectively, were obtained. The incorporation of PPy into the PVA/CMC blend led to a regular rise in the refractive index value within the visible range. The blend doped with 0.5 wt % PPy exhibited the highest optical dielectric constant values within the visible range. The enhancement/reduction in the fluorescence intensity depended on the excitation wavelength and the amount of PPy doping in the blended polymers. The effect of voltage, temperature and the amount of PPy doping on the current behavior of the resulting electric current in all blends was explored. The ohmic and nonohmic natures and the charge transport mechanisms of different blends were determined.

Tuning of optoelectronic performance of SrTiO3 by surface termination and thickness

The outstanding optical and electrical properties make ternary oxides highly suitable for advanced optoelectronic applications comparing to the traditional silicon-based materials and heterostructures. SrTiO3 (STO), a pivotal perovskite oxide with a direct energy band gap of 3.2 eV, exhibits significant promise in ultraviolet (UV) photodetection. However, the photovoltaic performance of homoepitaxial STO has long been neglected. In this study, we investigated the optoelectronic characteristics of STO by manipulating the crucial factors of surface termination and thickness using oxide molecular beam epitaxy (oxide MBE). We achieved an exceptional charge carrier mobility of 56.5975 cm2 V-1s−1, along with an impressive ON/OFF ratio of 6000 % and a specific detectivity (D*) of 2.95 × 109 Jones (cm Hz1/2 W−1) under near-UV irradiation at room temperature. We observed a thickness-dependent semiconductor-to-metal transition with a critical thickness of 3.5 u.c. STO. The metallic STO displayed an extremely high mobility exceeding 105 cm2 V−1 s−1, accompanied by a substantial MR value exceeding 1000 % at 3 K. Furthermore, the thickness-dependent Hall effect and photoluminescence (PL) indicated that oxygen defects may govern the semiconducting/metallic behavior of STO. This study illustrates the optoelectrical capabilities of homoepitaxial STO, paving the way for advanced and high-performance photodetection in intricate optical materials and devices through homoepitaxy.

Structural, optical and electrical conduction characteristics of PMMA/PVAc/TBAI blended polymers

This study aims to create tetra-n-butylammonium iodide (TBAI) doped poly(methyl methacrylate) (PMMA)/polyvinyl acetate (PVAc) blended polymers for utilize in a diversity of optoelectronic applications. By the casting technique, the films of (PMMA/PVAc/x wt % TBAI) were formed. The structure and morphology characteristics of the blended materials were studied using X-ray diffraction and scanning electron microscopy techniques. The optical transmittance declined to a minimum value when the blend was loaded with 38 wt % TBAI. The blend containing 38 % TBAI exhibits the highest reflectance values in the visible range. The lowest direct optical bandgap energies (4.20 eV) and indirect optical bandgap energies (3.71 eV, 3.13 eV) were achieved when TBAI reached 38 wt%. The addition of TBAI leads to an enhancement of the refractive index values of PMMA/PVAc in the visible spectrum. The effect of TBAI doping amount on the optical dielectric constant, energy loss functions, optical conductivity, nonlinear optical parameters and emitted color of the host blend was explored. The maximum values of the optical dielectric constant and energy loss functions were achieved after the TBAI level reached 38 wt%. The three non-linear optical (NLO) parameters for PMMA/PVAc blended polymers were enhanced as the amount of TBAI increased. An increase in voltage (V) or temperature results in a significant increase in electric current (I). Raising the amount of TBAI doping also caused the electric current to rise irregularly, with the exception of the blend with x = 11 %, where it fell. The samples exhibited the non-ohmic characteristics of the current-voltage (I–V) properties. The conduction mechanism of all blended materials was studied in detail. Finally, the outcomes supported the optical and electric properties studies, which suggested that a range of nanoelectronics applications could make use of the PMMA/PVAc/x weight percent TBAI blended polymers.

Impact of bismuth oxide on structural, optical and gamma-ray shielding properties of calcium-sodium-borate glasses.

In the present study, we have prepared six glass samples of bismuth borate using the melt-quenching method with the composition (70-x)B2O3-10CaO-20Na2O-xBi2O3; x=0, 3, 6, 9, 12 and 15mol%. The density of the prepared glasses was determined using Archimedes principle. The X-ray diffraction patterns provide confirmation of the amorphous nature of the prepared samples, whereas the Fourier transform infrared measurements pointed to the existence of structural units like BO3, BO4, BiO3 and BiO6 within the glass network. An assessment of the optical absorption spectra unveiled that with the increase in the bismuth oxide content, there was a decrease observed in both the direct and indirect band gap energies. Specifically, they decreased from 3.40 to 2.79eV and from 3.10 to 2.46eV, respectively. The properties related to gamma ray attenuation, including the mass attenuation coefficient (μm), effective atomic number (Zeff), half-value layer (HVL) and mean free path (MFP), were examined for all the glass samples. This investigation was carried out using the Phy-X/PSD software, covering the energy range from 0.511 to 1.332MeV. Out of all the samples, Bi-15, featuring the highest Bi2O3 content, demonstrated the highest μm, Zeff, the smallest HVL and MFP. These results suggest that the glass with 15mol% of Bi2O3 offers the most effective gamma radiation shielding performance. Moreover, the glasses examined in this study exhibit superior radiation shielding characteristics compared with specific concrete types, namely, ordinary concrete, Hematite serpentine concrete and barite concrete, as well as commercial glasses such as RS-360 and RS-253.

Elaboration, Structural and Optical Characterization of the New Ternary Chalcogenide SnSb<sub>2</sub>S<sub>5</sub>

In this study, -antimony sulfide (SnSb2S5) thin films with 200 nm, 312 nm, and 431 nm thicknesses were successfully fabricated using thermal evaporation. These films' structural, optical, and photoanode properties were meticulously characterized to assess their suitability for photovoltaic applications. X-ray diffraction (XRD) analysis confirmed the presence of an orthorhombic symmetry phase within the <em>Pnma</em> space group, ensuring the crystalline quality of the films. Raman spectroscopy further validated the crystal structure and provided detailed identification of the vibrational active modes specific to this pseudo-binary chalcogenide compound. Optical characterization revealed that the SnSb<sub>2</sub>S<sub>5</sub> thin films possess direct optical bandgap energies ranging from 1.91 to 1.99 eV, making them ideal for efficient light absorption in photovoltaic devices. The refractive index (n) displayed minimal variation within the absorption region, indicating stable optical properties. At the same time, it increased proportionally with film thickness outside the absorption region, suggesting enhanced optical behavior with thicker films. This characteristic is particularly advantageous for improving the efficiency of photoanode materials. The combination of favorable structural properties, optimal bandgap energies, and tunable optical responses positions SnSb<sub>2</sub>S<sub>5</sub> thin films as promising candidates for advanced photovoltaic and optoelectronic applications. These findings highlight the potential of SnSb<sub>2</sub>S<sub>5</sub> in developing high-performance photoanodes, contributing to the advancement of solar energy conversion technologies.

Effect of Sm3+ concentration on reddish orange photoluminescence and electrochemical properties of copper aluminate nanoparticles for display and supercapacitor applications

In this report, a novel synthesis method for Sm3+-doped copper aluminate nanoparticles (1–9 mol %) is presented, utilizing Ocimumsanctum leaves extract as a reducing agent through the solution combustion method, followed by calcination at 600 °C for 3 h. The resulting cubic spinel structure, validated by Bragg reflections, demonstrates a decrease in crystallite size and a direct energy band gap correlated with increasing dopant concentration. The morphology exhibits irregularly shaped nanoparticles and hexagonal shaped nanoplates. On deconvolution, three peaks situated at 579, 590 and 600 nm. The emission peak observed at 579 and 590/600 nm can be attributed to transitions from excited level G5/24 to its lower lying levels, H5/26, H7/26 respectively, with noticeable concentration quenching at 7 mol %. CIE and CCT coordinates affirm the red emission of Sm3+ within the host lattice, suggesting potential applications in residential and hospital settings. Cyclic voltammetry analysis provides insights into redox reactions, electrode kinetics, and electrochemical behavior. Electrochemical Impedance Spectroscopy (EIS) elucidates ion transport kinetics, while Galvanostatic Charge–Discharge (GCD) analysis determines supercapacitance values ranging from 53.89 F/g with increasing dopant concentrations. This material exhibits promise for applications in energy storage and display technology.

PVA/PEG/CuCo2O4/PANi/x wt% MWCNTs blended polymers: Improved the physical properties for energy storage devices and optoelectronic applications

The current investigation aims to enhance the optical and dielectric properties of poly (vinyl alcohol) (PVA)/polyethylene glycol (PEG) blended polymers via loading with copper cobaltite (CuCo2O4), polyaniline (PANi), and x wt% multi-walled carbon nanotubes (MWCNTs) for potential applications in optoelectronics and capacitive storage. The fabrication of PVA/PEG/CuCo2O4/PANi/x wt% MWCNTs blended polymers was carried out via casting and hydrothermal methods. Characterization of the blended polymer's structure and morphology was conducted using X-ray diffraction and scanning electron microscopy techniques. The impact of various fillers on the linear and nonlinear optical properties of the host blend was analyzed. The loaded blends demonstrated efficacy in blocking UVA, UVB, and UVC spectra, making them suitable absorbers for solar cells. The lowest values for direct and indirect optical band gap energy (Eg), of 5.34 eV and 4.44 eV were attained at x = 0.02. The blend with x = 0.01 displays the highest refractive index at λ = 600 nm. The optical conductivity exhibited nonmonotonically growth until peaking at x = 0.01. Analysis of chromaticity diagrams in CIE 1931 color space reveals that all blends emit blue-violet hues with slight variations in intensity. The fluorescence (FL) intensity of the doped blend is notably lower compared to the undoped counterparts. The doped blend (x = 0.03) showcases superior dielectric constants and ac conductivity values. The maximum energy density was achieved at 1 kHz for the host blend incorporating CuCo2O4/PANi. Overall, the observed characteristics indicate that PVA/PEG/CuCo2O4/PANi/x wt% MWCNTs blended polymers represent promising hybrid nanomaterials suitable for diverse applications.