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The structural, morphological, and optical features of a newly synthesized PQMHC ligand and its Cu(II)-coordinated complex were thoroughly investigated using powder X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and UV–Vis diffuse reflectance spectroscopy. XRD results confirmed that the PQMHC ligand crystallizes in an orthorhombic phase (space group Imma ), while the Cu(II)-PQMHC complex exhibits a monoclinic phase (space group P2₁/m ), indicating successful coordination with the metal center. FE-SEM images showed vertically aligned nanofibers, with average diameters of approximately 73 nm for the ligand and 52 nm for the complex, supporting their potential in optoelectronic applications. Diffuse-reflectance UV-Vis spectroscopy coupled with Kubelka–Munk/Tauc analysis yielded optical band gaps of (2.661 and 2.460 eV in the direct transition case) and (2.305 and 1.896 eV in the indirect transition case) for PQMHC and Cu(II)–PQMHC, respectively, consistent with charge-transfer-mediated gap narrowing upon complexation. The electrochemical properties of the PQMHC ligand and its Cu(II)-PQMHC complex were investigated using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Both the ligand and its Cu(II) complex demonstrated efficient electron transfer and rapid, linear sensitivity toward hydrogen peroxide detection within the 0.05–1000 µM range and a detection limit of 0.009 µM using the chronoamperometric (CA) technique. These enhanced electrochemical characteristics suggest their potential suitability for applications in sensors and biosensors.

A novel Cu(II) complex was synthesized from a reaction of 2-[(6-ethyl-4-hydroxy-2,5-dioxo-5,6-dihydro-2H-pyrano[3,2-c]quinolin-3-yl)methylidene]hydrazinecarboxamide (PQMHC) ligand with copper sulfate in a molar ratio 1:1 (L:M). Cu(II)-PQMHC complex was characterized by elemental analysis, mass spectra, infrared spectra, molar conductance, electron spin resonance spectra, electronic spectra, and thermal analysis. Kinetic parameters for the thermal decomposition steps were evaluated using the Coats–Redfern equations. The results of spectral data revealed that the ligand behaves as an O 2 N tridentate donor, coordinating through the hydroxyl group, azomethine nitrogen, and keto oxygen, forming a square planar geometry. Based on DFT, the molecular structure was optimized at B3LYP/6-311G(d, P) for the PQMHC ligand and at B3LYP/GENECP for the Cu(II)-PQMHC complex and interrelated with the experimental results. The optimized geometry of the Cu(II)-PQMHC complex is nonplanner as indicated by the dihedral angles. The HOMO–LUMO energy levels, total dipole moment, molecular electrostatic potential (MEP), thermodynamic properties, natural population analysis (NPA), natural bond orbital (NBO) analysis, non-linear optical (NLO) behavior, along with both global and local chemical reactivity descriptors were investigated. The electronic absorption spectra of the PQMHC ligand and its copper complex were investigated through the time-dependent density functional theory (TD-DFT) method at the CAM-B3LYP.

Thermal evaporation was used to deposit In 2 Se 3 thin films with a thickness of 276 nm on different glass and quartz substrates under vacuum. The 60 Co rays were used to irradiate thin films at dosages of 10, 20, 30, 40, and 50) kGy. X-ray Diffraction (XRD) and scanning electron microscopy (SEM) were used to investigate the crystalline and morphological structure of In 2 Se 3 thin films, respectively. The results revealed that powder has a polycrystalline structure, whereas pristine and irradiated thin films are amorphous. The computed absorption coefficient indicates that direct transition is allowed for the as-deposited and γ-irradiated thin films, and the value of the measured energy gaps increases when the dose is increased from 10 to 50 kGy. Using single-oscillator models to obtain the dispersion parameters, the spectral dependency of the refractive index in the higher wavelength area was studied. The effect of irradiation on dielectric constants and dispersion characteristics suggests that the examined films are highly sensitive to appropriate irradiation dose. The nonlinear optical susceptibility has improved, making it appropriate for a variety of device applications.

In this study, the effects of gamma radiation with doses ranging from 0 KGy to 100 KGy on the structural and optical properties of the Beta Metal-free Phthalocyanine (β-H2Pc) powder and films were investigated. X-ray diffraction and scanning electron microscope were used to examine the crystalline and morphological structures of the thin films. While Fourier transform infrared and absorption spectra were utilized to study the changes in molecular structure and energy absorption, respectively. The results showed that while γ-irradiation induced changes in the surface morphology and optical properties of β-H2Pc, the molecular structure remained stable except for the disappearance of the hydroxyl (OH) functional group peak. The irradiation dose was found to affect the dielectric constants, dispersion characteristics, and nonlinear optical susceptibility of the material. The β-H2Pc thin films exhibited high absorption coefficients and refractive index values, making them promising candidates for optoelectronic devices such as solar cells. However, careful consideration of the effects of gamma irradiation on other properties of β-H2Pc such as stability, toxicity, and cost-effectiveness is necessary.

In this investigation, highly adherent and unique advantageous properties of In 2 Se 3 films were prepared for different studies and applications using a thermal evaporation technique under a high vacuum on different substrates (including glass, quartz, and a p-Si single crystal). X-ray diffraction results show that the prepared In 2 Se 3 powder has a polycrystalline nature with α -phase. The average size of the crystallite, microstrain, and dislocation density was measured and found to be 273.6 nm, 4.9 × 10 –3 , and 1.34 × 10 –5  nm −2 , respectively. Due to the long-range array, the deposited In 2 Se 3 films have an amorphous nature. SEM images of the film surface were measured to examine the RMS roughness features and grain-boundary effect. Spectrophotometer measurements of transmittance and reflectance were used to estimate the optical constants of In 2 Se 3 films. The relationship between absorption coefficient and photon energy was tested, and the results revealed that the optical transition is directly allowed with an energy gap of 2.25 eV. The dispersion and oscillator energies were measured using the single oscillator model employing a relation of Wemple–DiDomenico and found to be 3.8 and 1.7 eV. The characteristics of the In 2 Se 3 -based junction showed promising candidates for photosensor applications under illumination. Graphical abstract

This study offers a comprehensive analysis of the thermal stability of β-metal-free phthalocyanine (β-H2Pc) powder, demonstrating its resilience at temperatures of approximately 470°C. The nanocrystalline nature of β-H2Pc was confirmed using scanning electron microscopy, particle size analysis, and atomic force microscopy. Furthermore, an extensive exploration of the dielectric properties of bulk β-H2Pc, in the form of compacted pellets, was undertaken over a wide frequency range (10 Hz–20 MHz) at different temperatures (303, 348, and 423 K), with consideration of the impact of DC-bias voltages (− 2 V to 2 V). Interestingly, the examined dielectric characteristics exhibited a substantial dependency on bias voltage, frequency, and temperature. The series resistance diminishes with increasing temperature, indicating enhanced device performance under elevated thermal conditions. In addition, this study delved into the photovoltaic characteristics of the β-H2Pc/p-Si diode under various illumination levels and was used to evaluate its potential for optoelectronic applications. The observed current density–voltage behavior demonstrates diode-like properties, with the generated current showing evidence of thermal activation. Furthermore, the Fill Factor decreased with increasing illumination intensity and power.

For the first time, a novel {3-cyano-5-[(1-methyl-4-hydroxy-2-oxo-1,2-dihydroquinolin-3-yl)carbonyl]pyridin-2(1 H )-ylidene}propanedinitrile (CMHQCPP) was synthesized and its thin films were made using a simple and effective process. FT-IR spectroscopy was used to investigate the vibrational properties, and the whole computational vibrational evaluation was predicted using DFT/B3LYP with the basis set of 6-311 +  + G(d,p). To extract the distinct geometrical optimization and other associated factors, simulation techniques employing TD-DFT/B3LYP were used. For the crystalline analysis, to offer a thorough identification of the crystal structure, indexing of XRD patterns was tried, and the mean crystalline size and the microstrain were measured to be 1.57 nm and 0.003, respectively. SEM was utilized to explore the surface shape and quality for a multitude of applications. The films’ optical bandgap was calculated using optical spectroscopic analysis. The optical band transitions of CMHQCPP were investigated using the most available transitions, and the direct optical gap was determined to be 2.14 eV. In metal/insulator/p-Si/metal configuration (Au/CMHQCPP/p-Si/In) devices, the dielectric characteristics of CMHQCPP thin films were investigated. The dielectric and modulus dispersions behavior is found to be frequency and temperature-dependent throughout a large temperature range of 304–413 K and frequency of 10 2 –10 6  Hz.

In the present work, CdS nanoparticles were synthesized and analyzed for use in fuel cell applications. The X-ray diffraction investigation showed that CdS possesses a cubic polycrystalline structure. For the (111) plane, the average values of mean crystallite size, microstrain, and dislocation density were calculated and found to be 1.935 nm, 0.0758, and 0.267 nm−2. The average crystallite size was additionally calculated and found to be 2.02 nm using the modified Scherrer’s plot. The observed blue shift in the photoluminescence of CdS is caused by the quantum size impact of the nanocrystalline structure. A broad emission band at 590 nm is produced by the recombination of a hole in the valence band of CdS with an electron confined in a sulfur vacancy. The average Cd/S ratio is good and comparable, according to the EDS analysis, which is close to the theoretical values and almost exactly fits the ideal structure. A thermogravimetry diagram was used to establish the thermal stability of CdS across a wide range of temperatures. Fuel cell application features peaks were investigated by the cyclic voltammetry of CdS under various conditions. The linear sweep voltammetry was used to analyze the electrochemical performance of CdS electrodes in fuel cells. Electrochemical impedance spectroscopy (EIS) was also used and the results confirmed that nickel substrate is regarded as being superior to stainless steel in terms of performance.

The aim of this study was to explore the potential of nanocrystalline β-metal-free phthalocyanine (β-H 2 Pc) in optoelectronics, particularly for the creation of a β-H 2 Pc/p-Si heterojunction. With a focus on photovoltaic performance, the present work aimed to assess its thermal stability, crystalline structure, optical characteristics, electrical behavior, and applicability in optoelectronic applications. We successfully fabricated a β-H 2 Pc/p-Si heterojunction at room temperature using a conventional high-vacuum thermal evaporation method, offering a practical approach for integrating these materials into electronic devices. Thermal gravimetric Assessment (TGA) confirmed β-H 2 Pc’s remarkable thermal stability up to 470 °C, which holds significant promise for high-temperature applications. Transmission Electron Microscopy (TEM) revealed the nanocrystalline nature of the deposited β-H 2 Pc, which is crucial for the structural integrity of advanced electronic devices. The absorption coefficient spectrum exhibited distinct absorption bands attributed to π–π * excitations, with electronic transitions identified and characterized by a 1.51 eV onset band gap and a 2.74 eV fundamental optical energy gap, highlighting its potential in optoelectronic applications. The current–voltage characteristics of the β-H 2 Pc/p-Si heterojunction displayed a diode-like behavior at various temperatures, with excellent rectifying properties. Photovoltaic behavior under illumination showed a power conversion efficiency of 1.1%, emphasizing its promise for renewable energy applications and future optoelectronic devices. Article Highlights Achieved β-H 2 Pc/p-Si heterojunction at room temp., enabling versatile electronic device integration. β-H 2 Pc's remarkable stability up to 470 °C validated, promising for high-temp applications. β-H 2 Pc/p-Si heterojunction exhibits diverse optical properties, ideal for optoelectronic devices, with 1.1% power conversion efficiency. Graphical abstract

Zinc oxide (ZnO) nanocrystallites with different Ga-doping levels were successfully prepared by spin coating sol–gel technique. The morphological properties of Ga doped ZnO films were studied by atomic force microscopy (AFM). Alignment of ZnO nanorods with respect to the substrate depends on the amount of Ga dopant content. The dopant content varies from 1 % to 4 %, based on Ga-doping levels. The optical properties of the ZnO nanocrystallites following Ga-doping were also investigated by UV–Visible absorption and Photoluminescence spectra. Our results indicate that Ga-doping can change the energy-band structure and effectively adjust the intensity of the luminescence properties of ZnO nanocrystallites. Transmittance spectra of the films indicate that the films have high transparency. The refractive index dispersion was analyzed by single oscillator model developed by Wemple and DiDomenico. The oscillator energy, dispersion energy, high frequency dielectric constant values for the films were determined were calculated and it is found that the optical parameters are changed with Ga-doping content.