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In this investigation the synthesis, structural and optical characterization of terbium-doped ZnO-ZrO 2 -ZnZrO 3 luminescent coatings, deposited by ultrasonic spray pyrolysis technique, are presented. These coatings were deposited at various substrate temperatures and were doped with different concentrations of the Tb3+ ions within the precursor solution. The XRD results for these coatings exhibited that their crystalline structure is subject to the deposition temperature. In the luminescence study, with an excitation wavelength of 270 nm the emission spectra were recorded, and all these spectra exhibit bands corresponding to the electronic transitions of trivalent terbium ions. When these samples were excited with 380 nm, the PL emission generated was reddish, probably produced by crystalline defects in the existing oxides. The concentration quenching effect appears at doping concentrations greater than 10 atomic percent inside the precursor solution. More information about the morphological and optical characteristics of these samples was obtained through techniques such as: SEM, TEM, EDS, and Diffuse Reflectance. Decay time study of the 544 nm characteristic green emission of Tb3+ ion was also obtained. [ABSTRACT FROM AUTHOR]

In the present study, the synthesis, structural, electronic, and optical characteristics of Dy3+-doped KZr 2 PO 4 3 nanophosphors are investigated. X-ray diffraction is used to investigate the structural conformation, which is found to be rhombohedral in phase. The elemental presence of K, Zr, P, O, and Dy is confirmed by x-ray photoelectron spectroscopy (XPS) studies in the KZr 2 PO 4 3 sample. Using photoluminescence (PL) spectroscopy, the variation in the PL spectrum due to the incorporation of Dy3+ ions is effectively studied. The analytical formula based on Dexter's theory is used to analyze the process of concentration quenching; results show that it is attributable to the quadrupole–quadrupole interaction, and the maximum Dy3+ concentration is observed at 1.5 mol.%. A value of 4.52 eV is found for the optical direct bandgap. These findings indicate the phosphor may be used in solid-state lighting applications as white light-emitting diodes (WLEDs) when stimulated by a near-UV source of 348 nm, since its CIE coordinates are comparable to those of white light. [ABSTRACT FROM AUTHOR]

Transition metal dichalcogenides (TMDs) have attracted enormous research interest in light of their exceptional electro-optical and electrochemical characteristics. Ion implantation is an appealing trend for the tailoring of the significant properties of thin films for use in practical applications. In the present work we illustrate the influence of Xe ion implantation on different characteristics of MoS2 thin films synthesized using the sputtering technique. This work offers an efficient approach for the tailoring of native defects in MoS2 thin films. The thin films implanted with Xe ions exhibit distinct fluence ranges from 3 × 1014 to 3 × 1016 ions/cm2. The surface morphology, crystal structure, and optical characteristics of the pristine and Xe ion-implanted samples were studied by atomic force microscopy (AFM), x-ray diffraction (XRD), UV-visible spectrometry, x-ray photoelectron spectroscopy (XPS), and photoluminescence (PL) spectroscopy. The crystalline nature of the ion-irradiated thin films was altered under the influence of ion beam implantation. Ion beam treatment resulted in changes in the lattice strain of the nanostructured thin films. The indirect optical bandgap of ion-implanted samples increased with the increase in ion implantation fluence. The PL spectra displayed a redshift in the emission peak on account of bandgap tuning during ion implantation. Our results provide an understanding of the relationship between the tailored characteristics of the films and the induction of defects by ion beam implantation and also offer insight into the generation of defects in a controlled and precise manner. [ABSTRACT FROM AUTHOR]

Graphene oxide (GO) has been synthesized by modified new Hummer's method with the help of Graphite flakes with sodium nitrite due to its various applications in physical, chemical, and medical sciences. The structure and morphology of GO are characterized using XRD, FTIR, RAMAN spectroscopy, and SEM. The results confirm that the synthesized material is graphene oxide (GO). The synthesized graphene oxide is used in perovskite solar cell as ETL layer. [ABSTRACT FROM AUTHOR]

HfO2 has allured the significant attention on account of its chemical and thermal stability, large bandgap value, high dielectric constant and refractive index, good transmittance values in ultraviolet and infrared bands establish it as a significant candidate for resistive switching oxide and optical materials. In the present work the effect of Ag ion beam with 120 MeV high energy treatment of HfO2 ALD grown thin films with thickness 40 nm is examined at distinct ion fluence from 1E12 to 1E13 ions/cm2. The present work reports the influence of 120 MeV Ag ion beam irradiation on the optical, structural and morphological characteristics of thin films grown by ALD method on glass and silicon substrate. The Tauc plots have been used to calculate the optical bandgap of films give the details of structure of films on account of slope of the plot is associated with the degree of the order in the network of bond. The SRIM simulation has been explored for the study of electronic and nuclear energy loss takes place in the samples. Structural analysis of pristine and ion beam irradiated thin films were studied by the X-ray diffraction technique. The effect of ion beam irradiation on the surface morphology were studied by the Atomic Force Microscopy (AFM), reveals that grain size rely on the variation takes place in the ion beam fluence. The ion beam causes surface state and interstitial defects in thin films samples as remarked by the Photoluminescence characterization method. Additionally, the RBS was used for the calculation of thickness of films. [ABSTRACT FROM AUTHOR]

In this investigation, we focused on the synthesis and characterization of CsCaF3 compound doped with europium (Eu3+) ions using a solid-state route. To analyze the crystal structure of the synthesized phosphors, X-ray diffraction analysis was employed. Additionally, the doped sample underwent examination of surface morphology and elemental composition through Field Emission Scanning Electron Microscopy and EDAX mapping. The color of the pure and doped CsCaF3 sample was quantified and fitted using Color coordinate graph by the Commission Internationale de l'Eclairage (CIE). The red emission on the doped CsCaF3 compound was detected at 465 nm, which is the transition from 5D0 to 7Fj (j = 0, 1, 2, and 3). The 0.5 mol. % Eu3+ doped CsCaF3 sample was found to have a color purity of 81% and an associated color temperature of 1660 K, indicating its suitability for aesthetic lighting applications. Furthermore, thermoluminescence study, electron paramagnetic resonance (EPR), and effective atomic number (Zeff) calculations were conducted to provide valuable information for potential radiation dosimetry applications.

An analysis of the photoluminescence (PL) and thermoluminescence (TL) glow curves from the calcite sample collected from the Meghalaya basin is reported. The as-collected sample is thoroughly ground with an agate pestle-and-mortar set for 4 h and is annealed at 400°C for 2 h. An X-ray diffraction (XRD) analysis of the sample reveals cubic crystal structure. The collected sample morphology shows the presence of agglomeration. The bending and stretching of bonds inside the calcite in the fingerprint region is determined by the Fourier transform infrared (FTIR) spectroscopy. The photoluminescence excitation and emission spectra are monitored; they show well resolved peaks at 252 nm (absorption band), 395 nm and 509 nm (emission bands). An analysis of the thermoluminescence (TL) glow curve of calcite is performed using UV excitation for different UV exposure times (5 and 15 minutes), showing a linear response with the UV dose. The corresponding kinetic parameters, like order of kinetics, activation energy and frequency factor, are calculated using the computerized glow curve deconvolution (CGCD) technique. The collected calcite sample shows a good response with the dose, which may be useful for the environmental UV monitoring systems. [ABSTRACT FROM AUTHOR]

Combustion process was used to synthesize the dysprosium (Dy3+)-doped sodium calcium vanadate (NaCaVO4) phosphor. The structural, optical and morphological investigations were carried out with the dopant concentrations ranging from x = 0–3 mol% for which X-ray diffraction, photoluminescence spectroscopy, SEM and UV–Vis spectroscopy were used. We have explored that the XRD results indicate vibrant, clear and well-defined peaks that are matched to the NaCaVO4 standard card confirming that the phosphor powder crystallized in the orthorhombic phase with space group Cmcm. From the FESEM pictures, the particles had an agglomerated morphology with irregular shapes and sizes in the nm range. The PL properties of undoped and Dy3+-doped NaCaVO4 were investigated using a 310 nm excitation source to determine the suitability for use in displays. The emission spectrum exhibited two sharp peaks at 450–500 and 550–600 nm and a weak peak at 650–700 nm, which is assigned to Dy3+-emission transitions of 4F9/2 → 6H15/2 (blue), 4F9/2 → 6H13/2 (yellow) and 4F9/2 → 6H11/2 (red). Doping of NaCaVO4 with Dy3+ for x = 0.25–3 mol% concentrations resulted in band gap modifications in the range of 3.341–3.866 eV. The material that we have taken up might be investigated as a new phosphor that could be activated by UV light-emitting diode (LED) light for solid-state lighting and display applications. [ABSTRACT FROM AUTHOR]

The increasing quest for therapeutic alternatives in treating non-communicable chronic diseases like obesity has propelled research into bioactive peptides, with a particular focus on milk due to its rich protein composition and associated health benefits. Milk fermentation, a traditional process in dairy production, enhances the bioactivity of peptides, broadening their potential therapeutic uses. This study investigated the anti-obesity potential of peptides from bovine milk fermented by Lacticaseibacillus casei LBC 237, identifying 143 peptides, notably LGPV and EVPMP. In silico analyses revealed that LGPV and EVPMP biopeptides exhibited significant interactions with target proteins, employing various molecular interactions such as Van der Waals forces, hydrogen bonds, and electrostatic interactions. These peptides shared common binding sites in some enzymes, suggesting a similar mode of interaction between molecule and target protein, akin to key pharmaceuticals recommended for treating these pathologies. Furthermore, amino acid characteristics present in the peptides, including hydrophobic residues like Leucine, Glutamate, Valine, and Proline, proved essential for their bioactive and inhibitory activities. These findings highlight the potential of LGPV and EVPMP biopeptides as therapeutic agents in managing obesity and metabolic disorders. They provide important insights into their mechanisms of action, paving the way for future research to apply them practically in preventing and treating metabolic conditions. [ABSTRACT FROM AUTHOR]

This study demonstrates the successful synthesis of SrZr(PO4)2:Dy2O3 solid solutions via solution combustion method, employing glycine as fuel. Powder X-ray diffraction (XRD) confirmed the crystal structure, while scanning electron microscopy (SEM) provided detailed insights into the surface morphology. Fourier transform infrared (FT-IR) spectroscopy identified the functional groups present, further revealing the material's composition. Photoluminescence (PL) measurements reveal excitation bands at 350, 365, 390, 425, and 450 nm; emission bands at 480, 580, and 665 nm. Emission color of the sample plot in the CIE x,y co-ordinates reveal white emission close to the standard white (0.33,0.33) demanded by the international television committee. Finally, dielectric studies revealed promising potential for long-term energy storage applications, particularly in super-capacitors. [ABSTRACT FROM AUTHOR]

In this research work, nanocomposites of CuO/TiO2 were initially fabricated using drop casting method. Later on, these nanocomposites were irradiated for the first time by a beam of Argon ions (Ar+) by keeping the fluence rates of 1×1014 ions cm−2, 1×1015 ions cm−2, and 1×1016 ions cm−2, respectively. In order to observe structural and optical properties of un-irradiated and irradiated nanocomposites, Raman Spectroscopy, Energy Dispersive X-ray (EDX), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Photoluminescence (PL) and Diffuse Reflectance Spectroscopy (DRS) analysis were performed. From Raman analysis, vibration modes confirmed the presence of different phases of TiO2 and CuO. EDX analysis clearly demonstrates the presence of Cu, Ti, and O peaks. SEM images depict agglomerated spherical nanoparticles having diameters in the range of 40–94nm. From TEM analysis, mean diameter of 56.1nm is observed for unirradiated and 33.7nm for Ar+ irradiated CuO/TiO2 nanoparticles in nanocomposite for fluence rates of 1×1014 ions cm−2, 1×1015 ions cm−2, and 1×1016 ions cm−2. HR-TEM and SAED images represent the polycrystalline nature of these nanocomposites.Among the three peaks of PL spectra in UV–Visible region, first two peaks were observed at 356nm, and 419nm but the third peak is little shifted from 488nm with the increase in fluence rate. Values of band gap are reduced from 3.29eV to 3.17eV as the fluence rate is increased, as calculated from results of diffuse reflectance spectroscopy. [ABSTRACT FROM AUTHOR]

In this current work, pristine Ti O 2 , BiV O 4 , and Ti O 2 /BiV O 4 ( 1%, 3%, 5%, and 7%) nanocomposites were prepared for the deteriorate of MB dye and tetracycline antibiotic. For synthesis aim, an easy and facile hydrothermal method has been utilized. Several characterization techniques like XRD, SEM, UV–Vis, and PL spectroscopic analysis have been performed to address the structural, morphological, and optical properties of the nanocomposites. It was observed that 5% Ti O 2 /BiV O 4 plays a significant role in decreasing the recombination rate of photogenerated electron/hole pairs, subsequently in the reduction of band gap. Interestingly, a nanocomposite of 5% TiO2/BiVO4 demonstrates the excellent deteriorate of Methylene and Tetracycline, with rates of 87% and 72%, respectively within 120 min. To check the stability of the optimized catalyst, recyclability and trapping investigations have been performed. Moreover, the 5% Ti O 2 /BiV O 4 photocatalyst exhibits good stability in five cycles for the degradation of MB dye and Tetracycline and paves a way for manufacturing innovation. [ABSTRACT FROM AUTHOR]

The synthesis and the structural and luminescence studies of samarium-doped calcium aluminate phosphors are reported. These phosphors are synthesized by the solid-state reaction method with a variable concentration of doping ions (0.5–3.0 mol%). The synthesized phosphors are characterized by the X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) techniques. The XRD studies show that the doped phosphors have a cubic structure. The SEM images reveal that the Sm3+- doped Ca3Al2O6 phosphor represents a combination of some rod-like and flower-like structures. The FTIR studies confirm the formation of a Ca3Al2O6:Sm3+ phosphor. The photoluminescence (PL) emission measurements upon excitation by 273 nm (ultraviolet light) show the characteristic emission peaks of Sm3+ at 579, 589, 600 and 619 nm. The characteristic orange-red emission is observed for samarium ion. The excitation spectra of the Ca3Al2O6:Sm3+ phosphor mainly consist of a more intense charge transfer band (CTB) of Sm3+ located at 273 and 395 nm with some peaks centred at 319 and 362 nm. The CIE coordinates are calculated by the spectrophotometric method using the spectral energy distribution of the Ca3Al2O6:Sm3+ sample. The prepared phosphors can act as a single host for orange-red light emission in display devices. [ABSTRACT FROM AUTHOR]

Synthesis and characterization of Eu3+-doped Er2SiO5 phosphor are reported. The samples are prepared using the modified conventional solid-state synthesis technique with variable concentrations of doping ions and their structural studies are carried out by X–ray diffraction (XRD). The information on the morphology of the samples prepared with optimized doping ion concentrations is obtained by scanning electron microscopy (SEM). A photoluminescence (PL) analysis of the phosphor samples is also done for the fixed doping ion concentrations. The identified PL emission bands are attributed to the intra 4f transitions of a Eu3+ ion, such as 5D0→7F1 at 590 nm, 5D0→7F0 at 602 and 5D0→7F2 at 613 nm. The corresponding transitions of the doping ions and the concentration quenching effect are studied in detail. The 1931 Commission Internationale de l'éclairage (CIE) (x, y) chromaticity coordinates show the spectral distribution calculated from the PL emission spectrum. A thermoluminescence (TL) glow curve analysis is performed for variable doping ion concentrations, and the corresponding trap parameters are calculated using the Computerized Glow Curve Deconvolution (CGCD) technique. Our study shows that as-prepared phosphor may be useful for display devices. [ABSTRACT FROM AUTHOR]

K Zr 2 PO 4 3 : xEu 3 + Nanophosphors with varying molar percentages (0.5, 1, 2, 3, 4, and 5 mol. %) are synthesized using a urea-assisted solution combustion synthesis approach. The phosphors exhibit crystallization in a rhombohedral phase, namely in the R 3 ¯ c space group with the help of X-ray diffraction. The anionic group of (PO4)3− is responsible for all the vibrations occurring in the FTIR spectra. The photoluminescence characteristics of K Zr 2 PO 4 3 : xEu 3 + (x = 0.5 – 5 mol. %) are examined when excited at a wavelength of 392 nm, resulting in the prominent emission at 613 nm. At a concentration of 2 mol. %, the optimal concentration is observed, and the emission tone of the phosphor is centered in the reddish part of the color gamut, with a high color purity of 92%. It is observed that the synthesized phosphor has a branching ratio more than 50%, indicating a possible laser emission transition. The band gap energy of K Zr 2 PO 4 3 : Eu 3 + is found via diffuse reflectance measurements and found to be 4.19 eV. The value of metallization criteria is less than unity which dictates the non-metallic nature of the synthesized phosphors. These results indicate that this phosphor is very suitable for use in solid-state lighting applications as a red light-emitting phosphor. [ABSTRACT FROM AUTHOR]

Zn0.75Cd0.25Sx (x = 1, 0.9, 0.8, 0.7, 0.6, 0.5) quantum dots were produced via thermolysis method. The structure and microstructures behaviors of Zn0.75Cd0.25Sx were examined using Rietveld refinement for the X-ray diffraction (XRD) data. A portion of the integrated O binds with Zn to create a segregated ZnO phase beside ZnS phase. The threshold sulfur deficiency with some O content incorporation into the Zn0.75Cd0.25Sx lattice without generating a new phase (ZnO) is x = 0.6. Zinc sulfide is the predominant phase, while the percentage of ZnO rises with increasing S deficiency (x). Zn0.75Cd0.25S0.8 has homogeneous spherical particle morphology with a very small size 2–4 nm, consistent with the XRD value. Zn0.75Cd0.25S0.8 has a homogeneous spherical particle morphology with very small size of 2–4 nm. The disorder's characteristics and defects were examined through Urbach energy analysis. The optical dielectric constant, optical conductivity and nonlinear optical parameters were calculated for all samples. The optical band gap lowers as the sulfur content increases up to x = 0.6, eventually reaching 2.71 eV. With a reduction in sulfur content to x = 0.5, two optical band gaps (2.8, 3.16) eV were obtained. The refractive index (n) values obtained using different models for all samples. As the molar ratio (x) of Zn/Cd to S increased, the PL emission peak of Zn0.75Cd0.25Sx nanoparticles exhibited a Stokes shift caused by S vacancies. The emitted colors from each samples were obtained by using Gaussian fitting for PL spectra. The fluorescence intensity greatly increased by increasing the S deficiency reaching its maximum value at x = 0.6. [ABSTRACT FROM AUTHOR]

A series of lanthanide-doped aluminosilicate phosphors has been synthesized by combustion methods using a stoichiometric ratio of oxidizer and fuel. Further, we investigated the luminescence properties and energy transfer mechanism of lanthanide-doped SrAl2Si2O8 nanocrystalline phosphor at room temperature. Crystallite size and phase identification have been carried out using powder X-ray diffraction and TEM analysis. Ln3+ (Ce3+, Dy3+, Sm3+)-doped SrAl2Si2O8 phosphor shows the characteristics excitation bands for each rare earth ions. Based on the corresponding d–f and f–f transition of rare earth ions and the spectral overlap of donor and acceptor ions we studied energy transfer process in Ce3+/Dy3+ and Ce3+/Sm3+-doped SrAl2Si2O8 phosphor. Thus, enhancement in PL intensity of phosphor occurred with appearance of characteristics spectral bands of rare earth ions. [ABSTRACT FROM AUTHOR]

We give a procedure to construct trisections for closed manifolds generated by colored tensor models without restrictions on the number of simplices in the triangulation, therefore generalizing previous works in the context of crystallizations and PL-manifolds. We give a description of how trisection diagrams can arise from colored tensor model graphs for closed 4-manifolds. We further speculate on generalization of similar constructions for a class of singular-manifolds generated by simplicial colored tensor models. [ABSTRACT FROM AUTHOR]

Alexandre Flückiger, Tracing the Evolutionary Path of Experimental Law: from Comparative Law to Regulatory Sandboxes (Śledzenie ewolucyjnej ścieżki eksperymentalnego prawa: od prawa porównawczego do regulacyjnych piaskownic), „Acta Universitatis Carolinae – Iuridica” 2024, vol. 70, no. 2, s. 13–22, https://doi.org/10.14712/23366478.2024.19 (opr. Karol Dąbrowski).

Abstract Research indicates that COVID-19 has had adverse effects on the mental health of adolescents, exacerbating their negative psychological states. The purpose of this study is to investigate the impact of Physical Literacy (PL) on Negative Mental State caused by COVID-19 (NMSC) and identify potential factors related to NMSC and PL in Chinese adolescents. This cross-sectional study involved a total of 729 Chinese high school students with an average age of 16.2 ± 1.1 years. Participants’ demographic data, PL data, and NMSC data were collected. PL and NMSC were measured using the self-reported Portuguese Physical Literacy Assessment Questionnaire (PPLA-Q), the Stress and Anxiety to Viral Epidemics-6 (SAVE-6), and the Fear of COVID-19 Scale (FCV-19). Adolescents in the current study demonstrated higher levels of NMSC and lower PL, with average scores of 3.45 and 2.26, respectively (on a scale of 5). Through multiple linear regression analysis, Motivation (MO), Confidence (CO), Emotional Regulation (ER), and Physical Regulation (PR) were identified as factors influencing NMSC in adolescents. The study findings contribute to providing guidance for actions aimed at alleviating NMSC among adolescents.

Mg 1−x O:Bi x (x = 0.01–0.5 mol%) nanophosphors have been prepared using the solution combustion method and subsequent annealing at 1173 K in air. Rietveld refinement on X-ray diffraction (XRD) data confirmed the rock-salt phase formation in pure and Bi3+ doped MgO (space group; F m ‾ 3 m). Lower Bi3+ ion concentrations in Mg 1−x O:Bi x (x = 0.01 and 0.05 mol%) lead to tensile strain and increased lattice parameters of MgO. Higher doping concentrations of Bi3+ ions (x = 0.1–0.5 mol%) lead to a decrease in the lattice strain, unit cell parameters, and Mg–O bond length. Transmission electron microscopy (TEM) images along with selected area electron diffraction (SAED) patterns confirmed the crystalline nature of Mg 1−x O:Bix samples with an average particle size of ∼37.5 nm. X-ray absorption spectroscopy (XAS) results at the Mg K-edge and Bi L-edge confirmed the Mg2+ ions and Bi3+ ions in Mg 1−x O:Bi x samples throughout the Bi doping range. O–K edge XAS conveys the hybridization of the frontier orbitals of O and Bi atoms. UV–visible absorption spectroscopy measurements convey the defect-induced absorption peak shifting in Mg 1−x O:Bi x compounds. Dopant and host defect-assisted PL emission is observed, with prominent emission in the blue region owing to the transition between 3P 1 to 1S 0 and 3P 0 to 1S 0 of Bi3+. The quenching effect on PL properties has been observed beyond 0.05 mol% doping of Bi3+ ions. The presence of various defect states and their stability with re-trapping and charge transfer behaviour have been analyzed by thermoluminescence studies of gamma-irradiated samples, which enable the Mg 1−x O:Bi x samples for potential applications in display device dosimetry. [ABSTRACT FROM AUTHOR]

Colloidal quantum dots (QDs) based on CdS were directly incorporated into a sol to fabricate solid rods. Various characterization techniques were employed to study the properties of the composite rod. A comparison between the absorption, emission, and excitation spectra of the QDs in the solid rod and in solution revealed their significant and stable nature in the solid state. SEM image shows that QD particles are well interacted with the sol gel environment. The observed particle size of QDs was heteronomous approximately from 5 to 10 nm. The XRD pattern of QDs illustrates their crystalline nature. The significant spontaneous emission (SE) signal was enhanced from QDs composite rod under the excitation of a 355 nm Pico second laser source. These findings suggest that further improvements in the integration of QDs into sol gel rods could be achieved by employing a higher density of QDs in the solid rod. The fabrication of QDs composite rods with a high concentration holds the potential for testing stimulated or amplified spontaneous emission in future studies.

In the present work, one-step, mass-scale productive solid state reaction method has been employed for the preparation of gadolinium (Gd) doped ZnO (GZOx: x = 0, 2, 4, 6, 8 wt%) nanostructures. The prepared GZOx samples have been studies their structural, morphological, elemental diffusion profile and optical properties using P-XRD, FE-SEM, EDS, FTIR, and photoluminescence (PL) spectroscopy. The powder X-ray diffractometer (P-XRD) results clearly indicate strong and sharp diffraction peaks with broadening that confirms the formation of hexagonal nanocrystalline structure of ZnO and Gd doped ZnO. The hexagonal morphology formation of the grains after doping of Gd contents into the ZnO nanostructures system is seen from the FE-SEM micrographs and the sizes of the grains are found to close to the results obtained from XRD patterns. The presence of Gd contents in ZnO matrix confirms its doping by EDS spectrum of 4 wt% Gd doped ZnO nanostructures. Fourier transform infrared (FTIR) results confirm the presence of functional groups and chemical bonding of ZnO at room temperature. Investigation of optical emission is interesting and the PL spectra reveal two emission peaks, one in UV-region located in the range of ∼385 to 395 nm and other is defects related emission centred at ∼450, ∼468, ∼503 and ∼562 nm in visible region for all the samples. The enhanced PL intensity is observed in the higher doped Gd contents in ZnO nanostructures and can be attributed to the presence of Gd ions into ZnO lattice. The detailed structural and luminescence analysis has been carried out and correlated. The study of structural and optical properties GZOx samples suggest the luminescent optoelectronic applications.

In this paper, photoelectrochemical etching of the n-type silicon (n-Si) wafers is used to prepare porous silicon (PSi) with current density of 10 mA.cm − 2 for 10 min. Moreover, the structural and morphological properties of the n-PSi were analyzed by using XRD and AFM, FTIR and PL. XRD patterns of PSi show that the films are single-crystalline, with cubic structure. The major peak characteristics are allocated to plane (004). The atomic force microscope image and the distribution chart of the grains of the n-PSi displayed that the grain sizes were −8.98. FTIR is a powerful and easy-to-use technique to obtain the surface chemical state of PSi. The convenience results from the transparency of silicon for IR light and the high surface area. The basic features begin from the knowledge of the bondings to hydrogen, [Si–H], and to oxygen [Si–O]. The model calculations sometimes provide useful information in the assignment. By examining FTIR, the active bonds showed the formation of PSi. PL spectra were measured in the range of (600–900) nm, the emission peak for the fixed excitation wavelength at 500 nm, and spectral 1.78 eV and 1.24 eV. PSi is recognized as an attractive building block for photonic devices because of its novel properties including high ratio of surface to volume and high light absorption. We first report NIR and VIS (PDs) fabricated by PSi as a carrier collector and a photoexcitation layer. [ABSTRACT FROM AUTHOR]

In the current study, PbO thin films were produced using the economical chemical bath deposition (CBD) technique. To determine the impact of annealing temperature, PbO thin films were calcined at 200 °C, 300 °C, and 400 °C. Different characterization techniques were used to assess the properties of PbO thin films. The XRD result demonstrates that both the α- and β-PbO phases are present in the deposited PbO films. The average crystallite size of the as-deposited PbO films was 36.50 nm. The average crystallite size for PbO films annealed at 200 °C, 300 °C, and 400 °C was 38.26, 48.48, and 51.34 nm, respectively. According to the UV–Vis result, the PbO film's energy band gap was 3.44 eV, 2.80 eV, 2.61 eV, and 2.24 eV for as-deposited, 200 °C, 300 °C, and 400 °C, respectively. PbO thin films annealed at 200 °C and 300 °C showed a prominent green band emission at 523 nm, according to photoluminescence spectroscopy. Nevertheless, it exhibits a red shift of 524 nm for as-deposited and annealed at 200 °C. The SEM analysis demonstrated the irregular and nanorod morphological distributions of particles on the surface of the substrates. The purity of the produced PbO thin films as well as the presence of Pb and O in their composition was verified by EDX. Based on the obtained characterizations results, the produced PbO thin films can be used in solar cells and for photocatalysis. [ABSTRACT FROM AUTHOR]

Zinc selenide doped with Sn and (Sn, Dy) phosphors has been prepared by firing the samples in an atmosphere of nitrogen gas. The voltage and frequency dependence of electrolyte brightness has been studied. Voltage dependence of electroluminescence (EL) brightness reveals an acceleration collision mechanism in the Schottky barrier at the metal–semiconductor interfaces. EL and photoluminescence (PL) spectra and thermoluminescence (TL) glow curves of these phosphors have also been recorded to understand the nature and mechanism involved in the luminescence process. The trapping parameters are calculated for the glow curves of these phosphors. [ABSTRACT FROM AUTHOR]

Nano Sn1−xFexS (x = 0, 0.025, 0.05, 0.075, 0.1) samples were prepared using thermal evaporation under flow of nitrogen gas. Rietveld analysis was applied to determine the structural and microstructural parameters of different phases formed in the Sn1−xFexS system. The particle morphology and size distribution of the different samples were explored using high-resolution transmission electron microscopy. X-ray photoelectron spectroscopy (XPS) analysis revealed Sn2+ oxidation state and confirmed the incorporation of iron as Fe2+. The photoluminescence (PL) intensity greatly enhanced with Fe content with broad spectrum enclosing violet and blue as main emitted colors beside green and weak yellow. The optical band gap Eg, obtained applying the Kubelka–Munk relation, changed nonmonotonically with the Fe doping amount attaining highest (1.17 eV) and lowest (1.1 eV) values for x = 2.5% and 7.5%, respectively. Nonlinear and linear optical parameters were studied in relation to iron doping ratios. [ABSTRACT FROM AUTHOR]

In recent times, there has been a surge of interest in the unique characteristics and possible applications of nanoparticles in various fields, including environmental clean-up. The contamination of water sources with pharmaceutical and organic substances has emerged as a significant environmental concern. Semiconductor nanoparticles, particularly Bi2S3 nanoparticles, have garnered considerable attention due to their efficacy and environmentally friendly nature in advanced oxidation processes (AOPs). These nanoparticles have shown remarkable photocatalytic abilities in the destruction of pollutants when exposed to UV–visible light. This study covers the production, characterization, and degradation of Bi2S3 nanoparticles in relation to organic and pharmaceutical contaminants. By utilizing co-precipitate methods, it becomes possible to precisely manipulate the size, shape, and composition of the nanoparticles, which are crucial factors in determining their catalytic effectiveness. The created nanoparticles are then examined using various analytical techniques, such as Powder X-ray Diffraction (P-XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), UV-visible spectroscopy, Photoluminescence study (PL), colour chromaticity coordinates (CIE), and Dynamic light scattering study (DLS). The catalytic capability of the synthesised compounds was compared to the degradation of Picric acid and paracetamol as model pollutants. The observed photocatalytic activity of these nanoparticles indicates their potential in water purification and environmental clean-up. The findings suggest that incorporating these nanoparticles into practical systems for pollutant degradation is feasible and can be applied in diverse scenarios. The results shed light on the efficient utilization of Bi2S3 nanoparticles as photocatalysts for the oxidation of drugs and organic contaminants. By utilizing Bi2S3 nanoparticles, the elimination of pharmaceutical and organic pollutants from water sources becomes achievable, thereby contributing to the preservation and safeguarding of the environment and public health.

The optical properties of Cu2O nanowhiskers grown by the liquid method with material deposition in an electric field have been studied. The spectral lines forbidden by the selection rules for perfect Cu2O crystals were found in the Raman spectra. The nature of related phonon states is analyzed. In the photoluminescence spectra in the red and near-IR regions, broad bands of defective origin are observed. It was found that the presence of a band at 650 nm (1.9 eV) is a specific feature of the photoluminescence of nanowhiskers. Its properties are studied and possible radiation mechanisms are discussed. In the intrinsic absorption region of nanowhiskers, the photoluminescence band at 572 nm (2.17 eV) associated with band-band transitions is detected. At a low excitation level, the emission of a free exciton n = 1 of the yellow exciton series is observed with simultaneous emission of an optical phonon. [ABSTRACT FROM AUTHOR]

The new compound based on mercury (II) (C7H10N)2·(HgCl2)2·(Hg2Cl6) 1 was described by numerous approach: X-ray diffraction (powder and single crystal), FT-IR, photoluminescence, UV–Vis, Hirshfeld surface analysis, thermal analysis, electric conductivity and finally a biological study was carried out through the antioxidant activity. Depending on the XRD data, the dimers (Hg2Cl6)2−, the infinite chains (parallel to the c-axis) formed by (HgCl2) and the 2-ethylpyridinium cation are bound together by weak H-bonds and electrostatics interactions forming a 3D network. The purity of 1 was checked by PXRD. The Hirshfeld surface analysis was used to investigate intermolecular interactions present in the compound 1. Infrared spectroscopy has been used to assign the varied functional groups. UV–Vis spectroscopy showed two bands located respectively at 240 nm and 280 nm. The photoluminescence analysis indicates the presence of fluorescence at 235 nm. A phase transition around 345 K has been shown by thermal analysis studies (TG-DSC and TG–DTA). The complex impedance of 1 has been performed in temperature range 295–343 K. Finally, the antioxidant activity study reveals that compound 1 can be used as a free radical scavenging substance. [ABSTRACT FROM AUTHOR]

CeO2 thin films have been deposited on fused silica substrates using RF-sputtering technique. 175 MeV Au13+ ions beam with two different fluences, 1 × 1012 ions/cm2 and 5 × 1012 ions/cm2, have been applied to modify the structural, surface and optical properties of CeO2 thin films. X-ray diffraction (XRD), atomic force microscopy (AFM), UV–visible absorption and photoluminescence (PL) measurements have been performed to investigate the 175 MeV Au13+ ion-irradiation induced changes in CeO2 thin films. The irradiated films show the formation of nanocrystalline granulizes on the film surface. The mud like cracks have been evolved at the ion-fluence of 5 × 1012 ion/cm2. The modifications in the optical and structural properties and the formation of cracks have been studied under the light of 175 MeV Au13+ ion irradiation and energy loss process into CeO2 lattice. [ABSTRACT FROM AUTHOR]

The ZnS nanoparticles doped with Tb3+ ions and ZnS doped silica glass-ceramic were synthesized by sol–gel method. The density, refractive index and various physical properties were calculated. X-ray diffraction (XRD) and selected area electron diffraction (SAED) studies confirm the formation of hexagonal polycrystalline structure. Transmission electron microscopy (TEM) analyses revealed that variation in size of the particles lies between 10 to 50 nm. FTIR were used to examine the structural characteristics of prepared glass samples at specific annealing temperatures. The band gap energy of the as-synthesized nanocomposite glass was 3.18 eV with a green light emission. The influence of ZnS nanoparticles on Tb3+ ions doped glass was studies by photoluminescence (PL) spectra. The PL emission intensity increased with the concentrations of ZnS. The CIE chromaticity revealed that the tunability of color changes from blue-green to yellowish green region as ZnS concentration increases. [ABSTRACT FROM AUTHOR]