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This research examines the electromagnetic EMI attenuation capabilities of the Titanium Silicon Carbide (Ti 3 SiC 2) MAX phase and their related compounds (Ti 2 C, Ti 3 C 2 , Ti 2 N, Ti 3 C, and Ti 3 N). The six investigated compounds' MAC, LAC, HVL, TVL, MFP, ACS, ECS, Z eff , N eff , C eff , and Z eq were visually estimated at (0.015–15 MeV) energy range to explain the photon interaction characteristics. At 0.1, 10, and 15, MeV, Ti 3 C, and Ti 3 N compounds exhibit the greatest values of MAC and LAC parameters and the lowest HVL than the other MAX phases. Ti 3 N compound exhibited the greatest ACS , ECS , and Z eff values of all the samples. For the other four compounds, the ACS , ECS , and Z eff values were the lowest. The Phy-X/PSD calculates the Z eff values of (electrons, protons, and alpha particles) as charged particles and photons precisely throughout the whole energy range. Therefore, the enhanced absorption of electromagnetic waves produced by powerful multiple reflections at the interior interfaces of the Ti-compounds structure may be attributed to the improved attenuation effectiveness. This research examines the potential problems in the future and offers design suggestions for new attenuation materials with adjustable electromagnetic wave absorption characteristics. [ABSTRACT FROM AUTHOR]

Different concentrations of Pt doped PbS nanostructures synthesis has been attained facilely by chemical route. X-ray diffraction (XRD) and FT-Raman spectroscopy analyses confirms the structure. After close inspection and indexing of diffraction peaks, the absence of additional peak owing to any contamination or free Pt in final products was confirmed. XRD data was further used to evaluate the lattice constants, crystallite size, density and strain to see the effect of Pt on these. Calculated lattice parameters confirm the single cubic phase, which was in correlation with vibrational modes analysis. The crystallite size was calculated in range from 9 to 11 nm. For further confirmation of Pt doping and its homogeneity in final product the EDX/SEM mapping was carried out and approved the homogeneous presence of Pt in PbS. SEM study revealed that the morphology is changing from nanoparticles (NPs) to nanosheets (NSs). Diffused reflectance spectra (DRS) were measured for powdered samples and energy gap was estimated up to 1.32 eV. Photoluminescence spectra was recorded and shows an intense green and broad red emission bands at 518 and 700 nm, correspondingly. The values of dielectric constant are found in range of 18–28. Total ac electrical conductivity is rising with applied frequency. The energy gap value suggest the application of synthesized Pt:PbS NPs and NSs in solar cell. SEM-image and PL emission spectra for synthesized Pt:PbS NPs and NSs. Image 108 • A facile one pot chemical synthesis of Pt:PbS NPs and NSs was achieved. • EDX/SEM mapping and XRD/Raman confirm homogeneous Pt doping and single phase. • SEM images revealed morphology change from nanoparticles to nanosheets with Pt doping. • Energy band gap values are found range of 1.16–1.32 eV (ΔE = 0.16 eV). • The emission spectra contains a major green emission peak at 518 ± 2 nm. [ABSTRACT FROM AUTHOR]

Zn-doped Molybdenum trioxide (MoO 3 :Zn) thin films were coated on glass substrates using a nebulizer spray pyrolysis technique to apply ammonia (NH 3) gas sensing. According to the structure examination, the crystallite size of the as-fabricated thin films is 64–77 nm. Field Emission Scanning Electron Microscopy (FESEM) images of the films confirm the formation of nanograins with islets-like shapes. In addition, Ultraviolet–Visible (UV–Vis) and photoluminescence (PL) studies were used to examine the samples optical bandgap and structural defects. Further, the MoO 3 : Zn sample's gas-sensing properties for ammonia detection were assessed at ambient temperature. The observed gas response of the MoO 3 :Zn3% sample was 20,900, and faster response and recovery times of 66s/9s. Furthermore, we observed that the MoO 3 :Zn3% sensor had exceptional ammonia selectivity. [Display omitted] • Zn-doped Molybdenum trioxide (MoO 3 :Zn) thin films were coated on glass substrates. • The crystallite size of the as-fabricated thin films has 64–77 nm. • FESEM images of the films confirm the formation of nanograins with islets-like shapes. • The observed gas sensitivity of the MoO 3 :Zn3% sample was 20,900%. • faster response and recovery periods of 66s/9s. [ABSTRACT FROM AUTHOR]

In the current work, the authors studied a hybrid organic-inorganic photodiode combining n-type monocrystalline silicon (n-Si) and indigo dye where the natural dye indigo has been applied as an interfacial layer between Gold (Au) and n-Si. The electrical and photo-response characteristics of photodiode based on indigo dye were investigated through current, conductance and capacitance studies measured under the wide illumination intensity and frequency ranges. The frequency dependency of capacitance-voltage (C-V) and conductance-voltage (G-V) characteristic properties of the Au/Indigo/n-Si photodiode was examined in the frequencies varying from 100 kHz to 1 MHz in view of the effects of series resistance (R s), the concentration of donor atoms (N d) and density of interface states (Nss). The C-V and G -V studies indicate that the N ss and R s are key factors which are strongly influencing the electrical properties of the fabricated Photodiode. From the obtained results, the fabricated Au/Indigo/n-Si photodiode can be a promising contender for electro-optic device engineering. Image 1060614 • Good quality nanostructured Au/Indigo/n-Si photodiode is developed. • The formation of spherical nanoclusters of 392 nm was approved by AFM study. • Capacitance is found to be increased from 2 × 10−10 to 1.7 × 10−9 with applied voltage. • The strong dependence of diode characteristics with the illumination intensity was noticed. • At lower frequency, the interface states exhibit very strong dependency on the frequencies. [ABSTRACT FROM AUTHOR]

Abstract The effects of TiO 2 nanoparticles on the PVA matrix can design new nanocomposites with new features in the structural, thermal and optical properties. Different nanocomposites films of TiO 2 -doped PVA are prepared using solution casting method. TiO 2 /PVA nanocomposites have been examined by using X-ray diffraction (XRD), (DTA), and UV–Vis–NIR spectrophotometric data. The XRD reveals the existence of both anatase and rutile phases of TiO 2. The crystalline size, Inter-crystallite separation, and the inter-planar distance are estimated and PVA crystallinity is enhanced as reflected from XRD studies. DTA studies conclude that the total crystallinity of the nanocomposites is improved after the addition of TiO 2. Optical characterizations of TiO 2 /PVA nanocomposite films have been determined. The transmittance spectrum of 37.037 wt % TiO 2 -doped PVA showed a blocking of the light in the wavelength region from 190 to 1275 nm which supports this material to be used as UV–Vis–NIR CUT-OFF laser filters with wide scale. The estimated direct optical band gap is varied from 5.6 eV to 2.11 eV with increased TiO 2 content. For analysis, the dispersion of the refractive index (n) and the dispersion parameters (E o and E d), Wemple–Didomenico single oscillator model is used. Optical limiting was measured and analyzed for the TiO 2 /PVA nanocomposites and the laser He Ne laser power was attenuated by increasing the TiO 2 -contents. It is possible to utilize TiO 2 /PVA nanocomposites in different aspects of laser power attenuations, wide-scale optical filters and UV-blocking for saving the human skin. Highlights • Novel and facile synthesis of different n-anocomposites films of TiO2-doped PVA by solution casting method. • The transmittance of 37.037 wt % TiO2-doped PVA showed a blocking of the light wavelength from 190-1275 nm. • The estimated direct optical band gap is varied from 5.6 eV to 2.11 eV with increased the TiO 2 content. • Optical limiting was measured and analyzed for the TiO2/PVA nanocomposites and He-Ne and solid-state green lasers. • TiO 2 /PVA nanocomposites can be used in different aspects such as laser power attenuations, and UV-blocking.. [ABSTRACT FROM AUTHOR]

Abstract The present work demonstrates the preparation of polypyrrole-decorated MnO 2 /rGO by oxidative polymerization method as well as in the presence of CNTs composites. The as-prepared nanocomposites are investigated by XRD, ATR-IR, Raman, TGA, and TEM techniques. Results illustrate polypyrrole with spherical nanoparticles covering the surface of MnO 2 /rGO and CNTs in which CNTs are intercalated between MnO 2 /rGO layers (Py@MnG2). In the meantime, the electrochemical performances for the obtained samples are investigated by cyclic voltammetry (CV), galvanostatic charge/discharge (GCD) and electrochemical impedance spectroscopy (EIS) experiments at 2 M KCl aqueous electrolyte. Owing to the presence of CNTs as well as the synergistic effect between polypyrrole and MnO 2 /rGO layers, the electrochemical performance of Py@MnG2 shows high specific capacitance of 295.83 F g−1 in a three-electrode system. The asymmetric supercapacitor (ASC) is assembled with Py@MnG2 and microwave exfoliated graphite oxide (MrGO) as positive and negative electrode material respectively. The as-fabricated ASC device exhibits a high energy density of 11.22 Wh Kg−1 and power density of 807.67 W kg−1 at 1 A g−1 in the potential window of 0–1.6 V. Moreover, the ASC device shows good cycling stability (78.42%) after 1000 cycles at 200 mV s−1. Highlight • A novel polypyrrole decorated MnO 2 /rGO in the presence of CNTs composite is prepared. • The as-prepared composite shows a high specific capacitance of 295.83 F g−1 in three-electrode system. • The assembled ASC exhibits a high energy density of 11.22 Wh Kg−1 at 1 A g−1. [ABSTRACT FROM AUTHOR]

Abstract Different thickness of basic fuchsin dye was deposited on conductive FTO substrate by spin coating technique for the first time. Their structural, morphological, linear/nonlinear optical and optical studies were performed. The structural studies confirm the amorphous nature of the studied dye on FTO substrate with original peaks corresponding to the FTO diffraction peaks. The morphological studies suggest the ellipsoid (spherical like) nanostructured of grain size of 235.6 nm and average roughness of 37.188 nm. Optical spectrophotometric studies were used to calculate various parameters like optical band gap, absorption index, and refractive index, dielectric constant/loss....etc. The electrical conductivity and optical conductivity are increased with the photon energy indicates the high absorption of the studied dye. Optical limiting studies were also performed using He-Ne laser of wavelength = 632 nm and solid-state green laser of wavelength = 532 nm. The normalized power is decreasing with increasing the thickness of the films. Our designed material can be used to control the laser power with specified percent for new applications of organic materials. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Pure and Ni-doped silver phosphate nanoparticles were achieved by co-precipitation strategy. • XRD and SEM supported Ni-doped Ag 3 PO 4 nanostructured and Energy gap was evaluated with diffused reflectance spectroscopy. • Various organic textile dyes were subjected for visible photocatalysis in presence of the prepared nanoparticles. • Photodegradation took place under various experimental conditions such as (effect of Ni2+ doping, H 2 O 2 , and pH of the medium). • This study boosts promising visible photocatalysts with high efficiency to different kinds of dyes. Abstract Pure and nickel-doped silver phosphate nanoparticles (Ni-AP) with different Ni2+ contents (i.e. 1, 5, 10, 15, 20 and 30%) were achieved by co-precipitation strategy. several analytical tools were used for materials characterization. X-ray diffraction (XRD) helped determine grain size, dislocation density, and lattice strain. Energy gap was evaluated with diffused reflectance spectroscopy (DRS). The morphological structure was shown through Scanning electron microscopy (SEM). All these data affirmed Ni-doped Ag 3 PO 4 synthesis. Various organic textile dyes including Levafix Brilliant Red dye (E-4BA), Remazol Black dye (RB5) and Reactive Orange 96 (RO96) were subjected for visible photocatalysis in presence of the prepared Ni-AP. The reaction was followed using a UV–vis spectrophotometer. 10% Ni-AP sample had the most suitable morphology due to Ni2+ dispersed uniformly over the Ag 3 PO 4 surface. Photodegradation took place under various experimental conditions such as (effect of Ni2+ doping, H 2 O 2 , and pH of the medium). This study boosts promising visible photocatalysts with high efficiency for different kinds of dyes. [ABSTRACT FROM AUTHOR]

Abstract Pure and potassium iodide (KI) doped hydroxyapatite (HAp) nanostructures were prepared through a facile microwave route. Field emission - SEM (FESEM) confirm low dimension nanorods (NRs) morphology of final products. The average dimension of NRs is may be in the range of 10–20 nm. Predominant single segment was approved by XRD and EDX analyses. Lattice constants, crystallite size, density of dislocations, strain and % of crystallinity were determined and the average crystallite size is observed in 9–16 nm range and degree of crystallinity is observed to be high viz. ~ 59% for 30% KI doped HAp. Vibrational studies were done through FT-IR and FT-Raman spectroscopy and confirm the phase of HAp. The catalytic activity of all samples is done in bioremediation of methylene blue using Stenotrophomonas maltophilia strain Kilany_MB. These results suggested that HAp and KI-HAp as a promising nano-catalyst in bioremediation of water from methylene blue. [ABSTRACT FROM AUTHOR]

The Au/Pyronin-Y/p-Si/Al Schottky diode was designed and studied by using the DC and AC measurements. Current-voltage ( I-V ), capacitance-voltage ( C-V ) and conductance-voltage methods under different frequencies and voltage biasing were measured at room temperature. The I-V characteristics and C-V characteristics were determined by using the electrical and impedance measurements. From I-V characteristics curve, the Au/pyronin-Y/p-Si/Al Schottky diode has a rectifying behavior. The parameters of Schottky diode such as the series resistance, ideality factor, and barrier height were computed for Au/Pyronin-Y/p-Si/Al junction diode. The performance of the Au/pyronin-Y/p-Si/Al diode is attributed to the creation of the interfacial layer by the organic semiconductor dye. Admittance spectroscopy method can describe the series resistance-voltage ( R s -V ) and impedance-voltage ( Z-V ), capacitance-voltage ( C-V ) and conductance-voltage ( G-V ) measurements at different frequencies at room temperature. This device showed a negative capacitance at higher frequencies. The origin of negative capacitance is attributed to the inductive behavior of the studied materials. From C-V analysis, different parameters were calculated and analyzed such as the doping concentration, the built-in potential, the depletion layer and the diffusing potential at zero bias. The obtained results support that the electronic properties of the silicon-based Schottky diode can be controlled by the interlayer organic layer (Pyronin-Y). [ABSTRACT FROM AUTHOR]

[Display omitted] • A one-pot combustion method successfully synthesized NiO @GLY. • Hexagonal nanocrystals appeared by increasing the glycine loading. • Hexagonal NiO @GLY was about 5–16 nm. • S 4 shows photodegradation efficiency of 99 % MB, 96 % RhB, and 93 % for the mixed dye. • The degradation mechanism was found to follow the pseudo-first-order kinetics. A venerable challenge in environmental and materials science is the degradation of organic contaminants from wastewater using visible-light irradiation. The nickel oxide nanocomposite was synthesized using the facile one-pot combustion method at 550 °C. XRD, TEM, and N 2 Sorption analysis confirmed the existence of mesoporous textured surfaces. Both spherical and hexagonal nanocrystals were produced with particle sizes ranging from 30 to 56 nm. The hexagonal nanocrystals appeared by increasing the glycine loading. The particle size of as-synthesized NiO @GLY was about 5–16 nm, with spherical morphology. The as-prepared hybrid composites were used to degrade harmful dyes. These produced systems seem to be governed by the interaction involving negatively charged nickel oxide nanoparticles and the amino group of glycine, as evidenced by zeta potential management. The degradation mechanism was found to follow the pseudo-first-order kinetics. S 4 shows a promising result with degradation efficiency of 99 % methylene blue, 96 % rhodamine B, and 93 % for the mixed dye. The enhancement is related to oxygen vacancies, which support the photocatalyst's activity and stability. [ABSTRACT FROM AUTHOR]

• The crystallization of the polymer matrix was decreased with increasing MYB content in the (PVA-PEG) blend matrix. • The FTIR spectra confirm strong conjunction of (PVA-PEG)/MYB films. • The UV–Vis absorption and photoluminescence emission wavelengths are highly coincidence. • In the frequency range of 100 Hz to 1 MHz, the MYB contents have an impact on the dielectric characteristics and AC electrical conductivity. • • This blend is very beneficial as a filter could be used in many industrial, medical and research applications. Using the casting technique, films of 90 wt% PVA/ 10 wt% PEG blend doped with numerous concentrations of methyl blue dye (MYB) were prepared. The effect of methyl blue dye on the unique functional groups of PVA and PEG was detected using a Fourier Transform infrared (FT-IR) spectrometer. The PVA/PEG blend's semi-crystalline characteristic was discovered via the X-ray diffraction pattern. With a rise in MYB doping concentration, the crystallinity of the doped blends degrades. The optical characteristics of the PVA/PEG mixture and the PVA/PEG mixture doped with various concentrations of (MYB) have been measured, including the absorption, transmission, reflection spectra, optical energy gap, optical absorption coefficient, and extinction coefficient. As the MYB dye's weight percentage increases, the composites show a decreasing energy gap and an increasing refractive index. As MYB doping rose, Urbach's energy surged from 8.5 meV to 28.88 meV. (PVA-PEG)/MYB composites demonstrated acceptable optical limiting characteristics. The emission peaks in terms of photoluminescence characteristics shift to red with rising MYB content in (PVA-PEG)/MYB MYB composite sample films, with the peak emission occurring at wavelength λem = 600 nm. According to research done in the frequency range of 100 Hz to 1 MHz, the MYB contents impact the dielectric characteristics and AC electrical conductivity. All of the aforementioned characteristics point to the (PVA-PEG)/MYB polymer composite as a promising choice for laser filters, solar cell technology, electric energy storage, and different optoelectronic applications. [ABSTRACT FROM AUTHOR]

Mo-doped Ag 3 PO 4 (AP) nanopowders with different Mo-ions loading (0–30%) were synthesized by a facile method of one-step synthesis procedure. Several techniques are used to characterize the as-prepared samples. X-ray diffraction technique (XRD) identifies the crystallographic phases. Light adsorption affinity and the band gap calculation by studied using optical diffused reflectance spectroscopy (ODR). Surface morphology was observed by scanning electron microscope (SEM). The characterization data confirmed the presence of Mo-Ag 3 PO 4 nanostructured with the new phase at the high doping of Mo. The photocatalytic activities of the as-prepared composites were evaluated by the photodegradation of methylene blue and colorless phenol under visible light illumination. The obtained photocatalytic results showed that the low doping of Mo in A 3 PO 4 matrix exhibit sufficient efficiency than that of high doping. The samples with 1% Mo-doped Ag 3 PO 4 nanomaterials exhibited much higher photocatalytic activity performance as the rate constant was about 0.55 min −1 and 0.12 min −1 for MB and phenol. While the rate constant was 0.2 min −1 and 0.06 min −1 in presence of pure Ag 3 PO 4 . Mo-doped A 3 PO 4 can consider as a new trend in the material design for photocatalytic decolorization activity. [ABSTRACT FROM AUTHOR]

The current study describes the main morphological and the photocatalytic performance differences between three zinc oxide samples; commercially available, synthetized tetrapods, and synthetized oxygen-defected sample. Oxygen-defected ZnO particles were prepared through a novel one-step thermal heating of metallic zinc powder at 1000 °C in a small concentration of oxygen gas. On the other hand, the tetrapods ZnO sample was prepared under the same conditions but in a high concentration of oxygen gas. The three materials were characterized by XRD, Raman spectroscopy, SEM, EDX, DRspectroscopy and finally EPR. The oxygen-defected sample has a grey colour and it tends to have a distorted tetrapods structure with a multitude of defect surface V O -Zn 2-x sites. Moreover, the absorption spectrum of the oxygen-defected sample showed a red-shift towards a visible light region as compared to that of commercial sample, with a calculated bandgap of 3.07 eV. The photocatalytic performance of the three materials was evaluated in the liquid phase decolourization of methyl green under the illumination of black UV light at 375 ± 10 nm and visible light 425 ± 20 nm. A high photocatalytic activity was observed for the oxygen-defected ZnO material under visible light illumination compared to the other two materials. [ABSTRACT FROM AUTHOR]

Pure poly (vinyl alcohol) (PVA) and PVA doped Fluorescein-Sodium salt (FSS/PVA composite films) have synthesized on wide scale laser optical filters. The investigated polymeric composite films have been characterized using several methods. The XRD patterns exhibit a decrease of the average crystalline size and an increase of the internal strain, which explained the imperfection and distortion in the prepared films. The optical characterizations showed a decrease in the transmission of the incident light for different samples, which may be explained to the layer formed by intermolecular hydrogen bonding between the PVA matrix and the FSS particles. The FSS/PVA polymeric composite films are being a completely blocking in the UV–Vis light at the range between 190 and 560 nm, agreement with the optical limiting effect, which makes the composite films suitable for CUT-OFF laser filters applications. The decrease in its, directly and indirectly, allowed transition band gaps were controlled by the added FSS dyes molecules. The variation of the exponent frequency ( s ) of the power law for FSS/PVA polymeric composite films has been characterized to improve the hopping conduction mechanism in the materials. The dielectric permittivity ( e ′) and dielectric loss ( e ’’) have been decreased with increasing the applied frequency, and the incorporated FSS molecules due to the DC electric conductivity can cause the decreases of the polarization of the as-prepared films over the studied ranges. [ABSTRACT FROM AUTHOR]

Poly(methyl methacrylate) (PMMA) doped with different weight percent of methyl violet-6B (MV-6B) as polymeric films were prepared by a casting method. Different concentrations of MV-6B can affect both the crystal structure and optical properties of PMMA. The broad hump diffraction peaks present in PMMA at 2θ  = 15.27°, 30.60°, and 40.69° are ascribed to amorphous PMMA. During the incorporation of MV-6B dye onto PMMA, the intense peaks of PMMA at the 2θ value of 15.27° and 30.6° became less intense, and d -spacing was changed. The X-ray results confirmed the strong electrostatic interaction of the cationic MV-6B dye with the anionic PMMA polymer. Furthermore, the transmittance of PMMA/MV-6B composites is decreased with the increase of MV-6B dopants concentrations onto the PMMA matrix; this may be attributed to the electrostatic interaction between the PMMA chains and the molecules of methyl violet-6B. MV-6B-doped PMMA possesses three distinct band gaps corresponding to the pure PMMA, and other two band gaps are for the MV-6B /PMMA composite films. PMMA/MV films with 3.333 wt% of MV-6B) showed a large scale CUT-OFF laser filter inside in the range from 190 to 670 nm. Our designed filter is a unique polymeric composite film for optoelectronic and laser applications. [ABSTRACT FROM AUTHOR]

Herein we report a low temperature, rapid microwave-assisted synthesis of pure and tungsten (W) doped hydroxyapatite (HAp) nanorods. X-ray diffraction study confirmed the good crystalline nature of synthesized product and various key parameters such as: grain size, dislocation density, lattice strain, degree of crystallinity and lattice parameters were estimated. The average value of grain size is found to be in the range of 11–32 nm and the highest degree of crystallinity was observed for 40 wt% W doped HAp (viz. ~ 67.3%). Functional groups and modes of vibrations were analyzed by FT-IR and FT-Raman spectroscopic studies. Morphology and elemental compositions of synthesized nanostructures were analyzed by FE-SEM/EDX measurements that confirms the formation of very low dimension nanorods (diameter<5 nm)/presence of dopant. Dielectric constant and ac electrical conductivity values are found to be enriched by doping. Gamma linear absorption studies were carried out using Cesium-137 ( 137 Cs) radioactive source and shows an enhancement in radiation absorption with an increase of doping which makes it useful in radiation shielding. Furthermore, the synthesized nanorods were applied to test their catalytic activity for methyl orange-removal in the presence of bacteria. The W doped HAp exhibited a great catalytic activity in presence of Enterococcus feacalis bacteria which indicates its applications in waste water treatment. [ABSTRACT FROM AUTHOR]

The design and characterization of indigo dye (C.I. Vat Blue I) have analyzed by several techniques such as XRD, FTIR; optically diffused reflectance based on the Kubelka–Munk model and electrical conductivity/dielectric properties that can use as natural organic semiconductor dyes. The XRD measurements revealed that the indigo dye has crystallized for the first time by using Crysfire and Check-cell assignment software in orthorhombic structure with a space group ( P 222 ) and both the optimized lattice and refinement cell parameters have calculated before and after refinement. FTIR supports the fingerprint groups of indigo dye. Based on the Kubelka–Munk model, it has noted that there are two optical transition bands equal to 1.847 eV and 1.721 eV related to the multi-graded band gap of the indigo dye that enhanced the light absorption and can make the indigo material to be used in solar cell and optoelectronic applications. The AC/DC electrical conductivities as function frequency/temperatures, respectively, parallel/series dielectric properties (real/imaginary parts) have investigated and interpreted by using the two-probe electrical conductivity measurement. The AC conductivity and dielectric properties can support the charge-hopping carriers of barriers of various heights. Indigo dye is a highly stable organic dye for new organic devices and technologies. [ABSTRACT FROM AUTHOR]

A specialized heterojunction of p -ZnTe:N/CdTe:Mg/n-CdTe:I/GaAs for varicap and high response signal diode applications was epitaxially grown by using molecular beam epitaxy. Frequency dependence of the capacitance-voltage, conductance-voltage and series -resistance characteristics in the frequency spectrum from 10 kHz to 10 MHz at ambient temperature was investigated. An increase in the capacitance is observed especially at lower frequency range that can be attributed to the predominant effect of interface states. A negative capacitance is observed and is explained on the basis of the loss of interface charges or interface states localized between metal and semiconductor due to impact ionization process. The frequency and voltage dependencies of the series resistance were investigated and characteristic peaks were observed for the voltage dependence of series resistance under low-frequency range. Some important parameters such as barrier height, carrier concentration, cut off voltage were also estimated and discussed. The electrical characteristics of p -ZnTe:N/CdTe:Mg/n-CdTe:I/GaAs show a good candidacy for electronic and optoelectronic devices. [ABSTRACT FROM AUTHOR]

Pyronin Y (PY) thin films of different thicknesses were deposited on a flexible polyacetate substrate by using the spin-coating method. Pyronin Y thin films have an amorphous structure as identified by X-ray diffraction method. The linear and nonlinear optical properties of PY thin films were studied in details as a function of wavelengths. Transmittance, absorbance and reflectance spectra of pyronin Y thin films were recorded in the wavelengths range from 300 to 2500 nm. The refractive and absorption indices have been computed from Fresnel’s equation. The optical band gaps were calculated for the studied PY thin film of thicknesses 205, 140 and 95 nm. Both direct and indirect gaps were computed as a function of PY of different thicknesses. The dielectric constant, dielectric loss and dissipation factor were investigated for the studied material. Spectrophotometric data was used to determine the nonlinear refractive index and the third nonlinear optical susceptibility. Pyronin Y thin films/polymer flexible substrate can be used in many applications such as flexible optoelectronic/electronic devices and for nonlinear optics with specified band gap. [ABSTRACT FROM AUTHOR]

In the current work, the authors report the microwave-assisted synthesis Molybdenum-doped (from 0.05 to 5 wt%) hydroxyapatite (HAp) for the first time. The morphology of Mo-doped HAp is nanorods of diameter in the range of 25–70 nm and length in the range of 25 nm to 200 nm. The good crystalline nature was confirmed from X-ray diffraction patterns and also lattice parameters, grain size, strain and dislocation density were determined. The crystallite size was found to be in the range 16 to 30 nm and crystallinity was found to be enhanced from 0.5 to 0.7 with doping. The field emission SEM micrographs show that the morphology of the synthesized nanostructures of pure and Mo-doped HAp are nanorods of few nanometers. The vibrational modes were identified using the FT-Raman and FT-IR spectroscopy. The dielectric properties were studied and the AC electrical conductivity was found to be increased with increasing the concentration of Mo ions doping in HAp. Moreover, antimicrobial studies were also carried out to understand the anti-bacterial and anti-fungi properties. The results suggest that it may be a good bio-ceramics material for bio-medical applications. Mo-doped HAp was subjected to the gamma irradiation produced from Cs-137 (662 keV) and its related parameters such as linear absorption coefficient, the half-value layer (HVL) and the tenth value layer TVL were calculated and analyzed. [ABSTRACT FROM AUTHOR]

In this work, heterojunctions of p-ZnTe:N/CdTe:Mg/ n -CdTe:I/GaAs for photovoltaic and photodiode application were grown epitaxially by using molecular beam system. Current-voltage profile of the heterojunction device was studied in dark and under various illumination intensities. The obtained photocurrent is found to depend on the light intensity. The main heterojunction parameters, such as shunt and series resistances, the barrier height and the ideality factor were extracted from the current-voltage profile using diverse methods at ambient temperature. Values of the barrier height and the series resistance were obtained from Cheung's functions. A large value of the series resistance causes the non-ideal characteristics of current–voltage measurements. The study of the current-voltage characteristics of high voltage region suggests a predominant space charge limited mechanism. Moderate values of short circuit current and open circuit voltage were obtained through a light intensity of 140 mW/cm 2 , a current and voltages of 0.336 mA and 370 mV, respectively. The high photosensitivity and responsivity for the current under illumination condition suggests that the prepared heterojunction device could be employed as a photodiode sensor. [ABSTRACT FROM AUTHOR]

This research work is devoted to studying the linear and nonlinear optical properties of anthracene thin films. For the first time, the fabrication of nanocrystalline anthracene films is presented by using the thermal evaporation conventional technique. All the studied anthracene films exhibit monoclinic crystal structure with dominant preferred orientation along the (001) plane in accordance with X-ray diffraction analysis. The average crystalline size and the strain parameter were calculated and found to be ≈ 14 nm and 42 lines 2 . nm, respectively. The transparency of the fabricated anthracene films is high (>80%) from the end of the visible to the near-infrared region at 1500 nm, after that; it reaches to 87%. The characteristic behavior, analysis of refractive index and absorption coefficient based on the measured spectrophotometric data of the transmittance and reflectance spectra. The transition is allowed one and the evaluated optical band gap ∼3.1 eV with energy tail ∼105 meV. The dispersion curves of the refractive index were found to follow the Wemple-DiDomenico model. The static optical dielectric constant was found to be 2.592. The molecular polarizability of anthracene thin films presented and its value ∼56.58 (Å) 3 . A simple spectroscopic method is used to characterize and estimate the nonlinear optical susceptibilities. Thermal evaporation technology could be useful to fabricate blue OLED and window film in photodetector devices based-anthracene films. [ABSTRACT FROM AUTHOR]

Four sulfide compounds' attenuation features of gamma-ray (Ag 2 ZnSnS 4 , Ag 2 ZnSnSe 4 , ZnS, and Ag 2 S) were described in this paper by a new software Phy-X/PSD. We calculated radiation attenuation parameters for the selected samples for a broad range of energies (0.015–15 MeV), including linear attenuation, the mean free path, the half-value layer, and total atomic and electronic cross-sections. The effective atomic number and the effective conductivity were also analyzed to investigate the radiation attenuation features. Also, the analyzed samples' buildup factors were studied. The samples' parameters were compared to materials frequently used to shield against radiation, including ferrite, chromite, barite, magnetite, and RS (253 G18, 360, 520) glass. Due to MFP and HVL values, Ag 2 S has better attenuation features than all the other samples utilized in the comparison. Fast neutron removal cross-sections (FNRCS) were also studied, and the best neutron attenuation composite among the samples under study, according to the FNRCS data, is Ag 2 S (0.116 cm−1). [ABSTRACT FROM AUTHOR]

Microwave-assisted synthesis of pure and Ag: Mn co-doped PbI 2 nanostructures have been reported for the first time. The structural and vibrational confirmations were carried out by X-ray diffraction and FT-Raman spectroscopic analysis. Furthermore, the EDX analysis confirms the presence of Ag and Mn in PbI 2 nanostructures. No extra phase due to impurity in the synthesized nanostructures was observed. The nanosheets like morphology were confirmed by SEM study for all the synthesized products. The average thicknesses of the prepared nanosheets are found to be in the range of ∼30 nm–50 nm. The dielectric constant is found to be enriched by Mn and Ag: Mn co-doping in PbI 2 compared to bulk value. The organized nanostructure with enhanced physical properties warrants the applications in optoelectronic devices and nanoscale radiation detectors. [ABSTRACT FROM AUTHOR]

Pyronin Y dye (PY) is a kind of xanthene derivatives. Thin films of pyronin Y were deposited onto highly cleaned glass substrates using low-cost/spin coating technique. The structure properties of pyronin Y thin films with different thicknesses were investigated by using X-ray diffraction (XRD) and atomic force microscope (AFM). PY thin films for all the studied thicknesses have an amorphous structure supporting the short range order of the grain size. AFM supports the nanostructure with spherical/clusters morphologies of the investigated thin films. The optical constants of pyronin Y thin films for various thicknesses were studied by using UV–vis–NIR spectrophotometer in the wavelength range 350–2500 nm. The transmittance T(λ) , reflectance R(λ) spectral and absorbance ( abs(λ) ) were obtained for all film thicknesses at room temperature and the normal light incident. These films showed a high transmittance in the wide scale wavelengths. For different thicknesses of the studied thin films, the optical band gaps were determined and their values around 2 eV. Real and imaginary dielectric constants, dissipation factor and the nonlinear optical parameters were calculated in the wavelengths to the range 300–2500 nm. The pyronin Y is a new organic semiconductor with a good optical absorption in UV–vis regions and it is suitable for nonlinear optical applications. [ABSTRACT FROM AUTHOR]

A PVA/Congo red composite film was prepared via casting technique. The effects of different concentrations of Congo red (CR) on the crystal structure and optical properties of polyvinyl alcohol (PVA) were characterized by X-ray diffraction and UV–vis spectroscopy. The PVA/CR films at different concentrations of CR displayed a relatively sharp peak at 2theta =19.51° and an additional weak broad peak corresponding to (200) plane of PVA at 2theta=22.35°. The transmittance values of PVA in UV–VIS above 600 nm were higher than PVA/CR films. Moreover, the transmittance of PVA/CR composite film decreased with the increase of CR dopant concentrations onto the PVA matrix; this could be attributed to the intermolecular hydrogen bonding between the hydroxyl group in PVA chains and the outer site groups (amino and sulfonate groups) in CR. Moreover, PVA/CR film (at 0.1 wt% CR) showed the properties of a broad scale cutoff filter in the UV–VIS range (190–566 nm). [ABSTRACT FROM AUTHOR]

Here, we report the doping effect of zinc (Zn) on the physical properties of cadmium oxide (CdO) at various concentrations (1, 2, 3 and 4 wt% of Zn). The studied samples were prepared using sol-gel in addition with sol gel spin coating technique. The structural, optical and dispersive properties were compared with the already reported work in the literature. The structural properties were observed by using atomic force microscopy (AFM). The AFM images show that the grain size decreases with increasing the concentration of Zn. The highest value of average cluster size (78. 71 nm) was found at 1% and the lowest (60.23 nm) when the doping concentration of Zn was 4%. Similar trend was observed in the roughness of the doped thin film when the Zn concentration was increased. The optical properties were examined using Shimadzu UV–Vis–NIR spectrophotometer and we found that the optical band gap of the un-doped CdO and the Zn-doped CdO thin films increases from 2.54 to 2.62 eV as the Zn concentration is increased from 1% to 4%. Also, the optical dispersion parameters ( E o , E d , n 2 ∞ , λ 0 and S o ) were calculated and discussed. We observed that the refractive index dispersion of undoped CdO and the Zn-doped CdO thin films follow the single oscillator model. Finally, spectroscopic method has been exploited to analyze the 3rd order non-linear optical susceptibility χ ( 3 ) and nonlinear refractive index n ( 2 ) . [ABSTRACT FROM AUTHOR]

In the present investigation, a bulk size (35 mm × 25 mm × 15 mm) single crystal of 0.1 wt% Methylene blue dye (MLB) added L-alanine is grown at room temperature using solution technique for the first time. The L-alanine crystals with higher concentrations of dye (0.5 and 1 wt%) were also grown. Solubility study was performed at different temperatures. Structural, vibrational and good quality was inveterate by powder XRD, FT-Raman and SEM analyses. High transmittance in dyed crystals was confirmed. The presence of MLB dye was confirmed by an absorption band centered at 650 nm. Optical band gap was calculated for pure and dyed L-alanine crystals and found to be 5.45 and 4.49 eV respectively. Photoluminescence intensity of UV-A emission band centered at 332 nm was found to be enhanced due to the presence of dye. The dielectric measurement was done in the wide frequency range. Furthermore, the third order nonlinear optical parameters are enhanced in dyed L-alanine crystals determined by Z-scan technique. [ABSTRACT FROM AUTHOR]

In this work, the authors have fabricated the nanorods and nanosheets of pure and Te-doped HAp with different Te concentrations (0.04, 0.08, 0.16, 0.24 wt%) by microwave-assisted technique at low temperature. The crystallite size, degree of crystallinity and lattice parameters are calculated. FE-SEM study confirms that the fabricated nanostructures are nanorods of diameter about 10 nm in undoped and at low concentration of Te doping. However, at and higher concentration, it becomes nanosheets of about 5 nm thickness. X-ray diffraction, FT-IR and FT-Raman studies shows that the prepared products are of HAp and Te has been successfully incorporated. From EDX the Ca/P molar ratio of the pure HAp is about 1.740, while this ratio for 0.04, 0.08, 0.16, 0.24 wt% Te doped is about 1.53, 1.678, 1.724, 1.792, respectively. Crystallite size was found to be increased with Te doping from 15 nm to 62 nm. The value of dielectric constant is found to be enhanced at higher concentrations of Te. The values of linear absorption coefficient were also determined and show that the prepared material with Te doping is more absorbable than pure and will be highly applicable in radiation detection applications. Furthermore, the antimicrobial potential of pure and Te doped HAp was examined against some Gram- negative and positive bacteria and fungi by agar disk diffusion method. The results demonstrated that the antimicrobial activity of Te doped HAp is stronger than that of pure HAp where it exhibited the highest activity against Bacillus subtilis > Candida albicans > Shigella dysenteriae . [ABSTRACT FROM AUTHOR]

In the current work, nanocrystalline undoped and Sn doped ZnO thin films with different doping concentrations (1, 3, 5, 7 at%) have been deposited on glass substrate by low cost spin coating technique. The strong effect of Sn doping on structural, morphological, optical, nonlinear properties have been observed. X-ray diffraction study revealed that all the thin films are preferentially grown along (002) plane. The crystallite size is found to be increased with increasing the concentration of Sn, similar behavior was observed by atomic force microscopy analysis. Optical study shows that the prepared thin films are highly transparent. The direct optical band gap was calculate and found to be 3.16, 3.20, 3.22, 3.34, 3.18 eV for pure and doped films respectively. The refractive index, linear susceptibility, nonlinear absorption coefficient, nonlinear susceptibility and nonlinear refractive index were calculated. Furthermore, the third order nonlinear optical properties are investigated using Z-scan technique and their values are found to be −3.75×10 −8 cm 2 /W, −3.76×10 −3 cm/W and 0.65×10 −3 esu for 7% Sn doped ZnO, respectively. There is a good correlation between theoretical and experimental third order nonlinear properties and higher values shows that the deposited films are may be applied in nonlinear optical applications. [ABSTRACT FROM AUTHOR]

Lithium-hydroxyapatite (0, 1, 5, 10, 20, 30 and 40 wt% Li-HAp) nano-composites were synthesized by sol-gel technique followed by microwave-hydrothermal treatment. The composites were characterized by X-ray diffraction (XRD), Field emission scanning electron microscope (FE-SEM), energy dispersive spectroscopy (EDS), Fourier transform infrared (FTIR) and Raman techniques. Gamma attenuation coefficient and the dielectric properties for all composites were investigated. The crystallinity degree of Li-doped HAp was higher than that of un-doped HAp. Gamma attenuation coefficient values increased from 0.562 cm −1 for 0 wt% Li-HAp to 2.190 cm −1 for 40 wt% Li-HAp. The alternating current conductivity increased with increasing frequency. The concentration of Li affect the values of dielectric constant where Li doped HAp of low dielectric constant can have an advantage for healing in bone fractures. The calcium to phosphorus ratio decreased from 1.43 to 1.37 with the addition of lithium indicating the Ca deficiency in the studied composites. Our findings lead to the conclusion that Li-HAp is a new nano-composite useful for medical applications and could be doped with gamma shield materials. [ABSTRACT FROM AUTHOR]

2′,7′ dichloro-Fluorescein (DCF) is a promising organic semiconductor material in different technological aspects such as solar cell, photodiode, Schottky diode. DCF thin film/conductive glass (FTO glass) was prepared by a low-cost spin coating technique. The spectrophotometric data such as the absorbance, reflectance and transmittance were cogitated in the 350–2500 nm wavelength range, at the normal incidence. The absorption ( n ) and linear refractive indices ( k ) were computed using the Fresnel's equations. The optical band gap was evaluated and it was found that there is two band gap described as follows: (1) It is related to the band gap of FTO/glass which is equal 3.4 eV and (2) the second one is related to the absorption edge of DCF equals 2.25 eV. The non-linear parameters such as the refractive index ( n 2 ) and optical susceptibility χ (3) were evaluated by the spectroscopic method based on the refractive index. Both ( n 2 ) and χ (3) increased rapidly on increasing the wavelength with redshift absorption. Our work represents a new idea about using FTO glass for a new generation of the optical device and technology. [ABSTRACT FROM AUTHOR]

Pyronin Y (PY) is an organic dye with semiconducting behavior which can be ascribed as a novel dye in different aspects of material science and device engineering. Thin films of Pyronin Y were prepared using a low-cost spin coating method deposited on FTO substrate. XRD showed that PY thin film has an amorphous structure with crystalline peaks corresponding only to FTO layer/glass. Transmittance, reflectance, and absorbance are measured for Pyronin Y/FTO of thickness around 200 nm at the normal incident light in the wavelength range 300–2500 nm. PY has an absorption valley in the visible region. Based on the measured transmittance and reflectance, the refractive index n of PY/FTO is calculated by using the Fresnel’s equations. Dielectric constants, dissipation factor, band gap and optical/electrical conductivity were also determined and analyzed. Plotting of ( α h ν ) 1 / 2 versus the incident photon energy is giving the values of the band gap. Three optical band gaps are found, the highest one is designed for FTO layer/glass and equals 3.569 eV and the other two band gaps are (1.955 and 1.356 eV) for Pyronin Y/FTO film. For PY films on FTO, the value of band gap (1.955 eV) is described the fundamental band gap and the second band gap (1.356 eV) is described as the trap energy inside the fundamental band gap. The nonlinear optical properties including the third order nonlinear optical susceptibility and nonlinear refractive index of PY/FTO glass were calculated and analyzed by using spectrophotometric data. Hence, Pyronin Y/FTO with a graded band gap have a unique optical constant that useful in multi-device applications for physics and engineering. [ABSTRACT FROM AUTHOR]

In the current work, good quality bulk size (∼32 mm × 23 mm × 10 mm) single crystals of HCl added l -alanine with well-defined morphology are successfully grown using slow evaporation technique. Crystal structure and other structural parameters were evaluated from X-ray diffraction data. Vibrational assessment of the grown crystal was done by FT-Raman analysis. The presence of chlorine and good quality of the grown crystal was confirmed by SEM/EDX analysis. Solid state UV–Vis–NIR diffused reflectance was measured and direct and indirect optical band gap was calculated using Kubelka-Munk relation and found to be 5.64 and 5 eV respectively. Dielectric measurement was carried out in high frequency range. Third order nonlinear optical susceptibility value was found to be enhanced from 1.91 × 10 −6 (pure) to 8.6 × 10 −6 esu (LAHCl). Good thermal stability of grown crystals was confirmed from DSC analysis. The enhancement in mechanical strength and crystalline perfection was also observed. [ABSTRACT FROM AUTHOR]

Graphene oxide (GO)/Ag 3 PO 4 nano-composite was successfully prepared by wet chemical technique. Samples were synthesized with three different concentrations of the GO. The structural studies such as grain size, dislocation density and lattice strain were performed by using X-ray diffraction (XRD) technique. The surface chemical state and doping process has been investigated by X-ray photoelectron spectroscopy (XPS). The evaluation of conduction band (CB), valance band (VB), direct and indirect band gap was performed through diffused reflectance spectroscopy (DRS). Surface morphology was observed through the field emission scanning electron microscope (FESEM). The obtained characterization results confirmed the formation of GO/Ag 3 PO 4 composite with slight decrease in the band gap based on the amount of GO incorporated inside the GO/Ag 3 PO 4 nano-composites. The photocatalytic performance of the prepared materials was evaluated in the decolourization reaction of methyl orange dye under the illumination of visible light radiation. The obtained photocatalytic results indicated that the addition of GO to Ag 3 PO 4 has improved its photocatalytic performance. The sample with small GO loading exhibited remarkable photocatalytic performance than the neat Ag 3 PO 4 , i.e. the rate constant was almost 3.5 times higher. [ABSTRACT FROM AUTHOR]

In the current work, the authors present the systematic study on linear and nonlinear optical properties of Copper-phathalocyanine thin film deposited by thermal evaporation system for the first time. The thickness of the prepared thin film was measured and found to be ~300 nm. X-ray diffraction and AFM study confirms that the prepared thin film possess good quality. The orientation of the grown thin film is found to be along (100). UV–vis-NIR study shows that the deposited thin film is highly transparent (>80%) in the wavelength range of 700–2500 nm. Further, the recorded optical data was used to determine the various linear and nonlinear optical parameters. The calculated value of refractive index is found to be in the range of 0.4–1.0. The direct and indirect band gap value is found to be 2.9 and 3.25 eV, respectively. The value of linear and nonlinear susceptibilities is found to be in order of 10 −12 . The higher value of linear and nonlinear parameters makes it suitable for optoelectronic applications. [ABSTRACT FROM AUTHOR]

Pyronin Y (PY) is an organic dye which is used extensively before in staining RNA and other organo-cells. Nowadays, it can be used in electronic and optoelectronic devices as an organic semiconductor. X-ray diffraction (XRD) showed that PY is a polycrystalline material and both the lattice structure and the lattice constants were calculated for the first time by using crysfire and checkcell software. In addition, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and differential thermal analysis (DTA) have been studied. Diffused reflectance (DR) of pyronin Y in the wavelength 200–2300 nm was measured and analyzed to calculate the optical parameters and the absorption region of pyronin Y. The optical band gap was calculated on the basis of Kubelka–Munk theory (KMT). It is clear that there are three optical band gaps in the studied range of photon energy and equal 2.13, 1.82 and 1.67 eV. The high band gap (2.13 eV) is corresponding to the fundamental band gap (between HOMO and LUMO) and other two gaps (1.82 and 1.67 eV) are corresponding to the trap energy inside the band gap (i.e. onset gaps). On the basis of the DR measurements and applicable of KMT, we are able to calculate the refractive index, absorption index and the dielectric constants for pyronin Y in powder form. Pyronin Y is an organic semiconductor due to the increasing of DC (direct current) electrical conductivity with increasing temperature and the electronic parameters of direct current was calculated. Ac electrical conductivity, dielectric constant and dielectric loss were calculated and interpreted on the basis of ac fields causes the different kind of polarization inside the materials. Hence, pyronin Y can be used as a new materials for advanced technology. [ABSTRACT FROM AUTHOR]

Lead iodide (PbI 2 ) nanostructures with different Gadolinium concentrations (1, 2, and 3%) have been fabricated by cost effective hydrothermal route at low temperature. The fabrication of well aligned nanorods of diameter about 100 nm and nanosheets of thickness about 10 nm were confirmed from SEM analysis. The structural and vibrational studies confirm the dominant nature as 2H polytypic PbI 2 of the fabricated nanostructures. The existence of Gd 3+ doping was confirmed by Energy Dispersive X-Ray Spectroscopy study. The clear blue shift of wavelength or enhancement in the band gap was observed due confinement effect as well as Gd 3+ doping. The dielectric constant was found to be reduced with doping however its value is still higher than bulk value. [ABSTRACT FROM AUTHOR]

[Display omitted] • Wide-scale CUT-OFF filter based on PVA /TB films was designed and characterized. • XRD, FTIR, UV–Vis-NIR, dielectric spectroscopy, and optical limiting are used to characterize PVA /TB films. • The direct and indirect allowed transitions have a multi-band bandgap structure. • Dielectric behavior and Electrical conductivity of PVA /TB films were discussed. • The suitability of the parameters calculated for optoelectronic and photonic devices were listed. Poly(vinyl alcohol), PVA doped with (0, 0.11, 0.55, 1.11, and 5.5) wt% of Toluidine Blue dye (TB dye) was prepared by the traditional casting method. The influence of Toluidine Blue dye concentration on spectroscopic, optical, and dialectical properties was investigated. Fourier transform infrared (FTIR) spectroscopies and X-ray diffraction were used to study the molecular and crystalline structure of PVA/Toluidine Blue dye composites. A UV–Visible spectrophotometer was used to investigate the optical characteristics. For all samples, the full-width half-maximum absorption spectra were determined. The direct and indirect allowed transitions have a multi-graded bandgap structure. Within the frequency range of 3 kHz to 10 MHz, the dielectric constant (ε′) and dielectric loss (ε″) were investigated and found to be dependent on the weight percent of TB dye. The correlated barrier hopping can describe the conduction mechanism for the studied samples. Furthermore, the PVA/5.5 wt% TB film demonstrated excellent optical CUT-OFF properties with a low transmission value in the spectral range (200–1300 nm), which is a favorable result for the fabrication of long-blocking optical filters and protective windows for optoelectronic and photonic devices like organic/polymer light-emitting devices, dye-sensitized solar cells, optical limiters, and optical switches. [ABSTRACT FROM AUTHOR]

• Theoretical and practical methods were used to study the impact of Eu3+ substitution on copper ferrites. • The intensity of quadrupole split lines decreases along with the reduction in temperature. • The presence of paramagnetic lines at temperatures lower than the Curie temperature, asymmetric lines. • DFT calculations support the preference for octahedral Eu-doping in combination with the CuFe 2 O 4 matrix. Here, theoretical and practical methods were used to study the impact of Eu3+ substitution on copper ferrites. The spinel cubic structure of the synthesised samples is crystalline, and XRD analysis revealed the presence of a trace amount of the impurity Fe 2 O 3 phase. The range of the estimated crystallite sizes is between 18 and 27 nm. FTIR spectra of the ferrites exhibited the presence of functional groups of spinel ferrites. The temperature-dependent Mössbauer spectra of CuFe 2-x Eu x O 4 (x = 0, 0.01, 0.02, 0.03) (CEF) were collected at 300 K, 200 K, 100 K, and 14 K. Room temperature spectra consist of asymmetrically broadened sextets and quadruple split lines. The intensity of quadrupole split lines decreases along with the reduction in temperature. The observed changes in the structure of the Mössbauer spectra are typical of nanosized particles. The presence of paramagnetic lines at temperatures lower than the Curie temperature, asymmetric lines with sharp external fronts, and significantly diffused internal fronts is a sign of superparamagnetic relaxation. The partial substitution of Fe3+ ions by Eu3+ ions causes the redistribution of A and B cations, which leads to the alteration in angle and bond length of magnetic superexchange links. DFT calculations support the preference for octahedral Eu-doping in combination with the CuFe 2 O 4 matrix, which results in local structural disorders that affect both the material's magnetic and electrical characteristics. The size, shape, interaction with the matrix, and crystallite characteristics all affect the material's magnetic properties. A weak ferromagnetic characteristic is indicated by the magnetic properties, and the magnetization values increase as Eu increases as a result of changes in crystallite size. As a result, our findings imply that synthesised samples are appropriate for applications involving hyperthermia. [ABSTRACT FROM AUTHOR]

Cadmium doped nickel oxide with different dopants concentrations (0, 1, 5, 10%, 20, 30 and 40%) were deposited on highly cleaned glass substrates using sol–gel/spin coating technique. The effect of cadmium doping on structural, morphologies and optical parameters have been studied in details. The XRD lines of the deposited Cd:NiO was enhanced with increasing cadmium doping content due to the improvement of the films crystallinity. The optical properties and the morphologies study of the deposited nanoparticles thin films have been discussed in this work. It was shown that the average of the crystalline size of the deposited thin films was calculated using Debye–Scherrer formula and found in the range between 15 and ∼10 nm also agreed with the size values which was extracted from SEM images. Optical parameters i.e. absorbance ( A ), transmittance ( T ), refractive index ( n ) were measured and calculated. Band gap energy is considered one of the most important optical parameter, therefore measured and found ranging between 2.95 and 3.30 eV. The real and imaginary part of the dielectric constant and optical conductivity of these deposited thin films were reported. Cd:NiO can be applied in different electronic and optoelectronic applications due to its high band gap and high transparency. [ABSTRACT FROM AUTHOR]

The aim of this research was to fabricate/deposit the good quality thin film of Rhodamine B dye on fluorine doped tin oxide glass substrate by the low cost spin coating technique and study their linear and nonlinear optical parameters. The thickness of the thin film was measured about 300 nm with alpha step system. The transmittance of the fabricated thin film was found to be above 75% corresponding to the fluorine doped tin oxide layer. The structural analysis was performed with X-rays diffraction spectroscopy. Atomic force microscope showed the topographic image of deposited thin film. Linear optical constant like absorption coefficient, band gap, and extinction index was calculated. The dielectric constant was calculated to know the optical response of Rhodamine B dye over fluorine doped tin oxide substrate. The nonlinear optical constant like linear optical susceptibility χ (1) , nonlinear optical susceptibility χ (3) , nonlinear refractive index ( n 2 ) were calculated by spectroscopic method. This method has advantage over the experimental method like Z-Scan for organic dye base semiconductors for future advance optoelectronics applications like dye synthesis solar cell. [ABSTRACT FROM AUTHOR]

Lead iodide (PbI 2 ) nanostructures have been synthesized by co-precipitation, hydrothermal and rapidly by microwave irradiation techniques. SEM analysis indicated the formation of well aligned nanocrystals and nanorods of average diameter between 100 nm and 400 nm. The powder X-ray diffraction and FT-Raman spectroscopic analysis confirms the formation of a 2H–PbI 2 polytypic predominantly. These studies also show that there is no extra phase due to impurity in the synthesized nanostructures. The optical energy band gap of nanostructures prepared by co-precipitation, hydrothermal and microwave irradiation techniques were found to be 2.283, 2.493, 2.542 eV and 2.331. 2.350, 2.375 eV calculated from UV–Vis absorption and diffuse reflectance data, respectively, which shows a clear blue shift in the wavelength due to confinement effect. Photoluminescence spectrum was recorded at different excitation wavelengths and shows clear blue shift in the emission peak which is due to the recombination of free excitons with band to band type transition and also may be due to confinement effect. Further the dielectric studies have been performed and a good enhancement in the dielectric constant has been observed due to small size of the fabricated nanostructures in comparison to bulk material. [ABSTRACT FROM AUTHOR]

Thin films of CuO nanorods with 300 nm thickness were prepared by using non-vacuum technique, spin coating sol–gel technique. Surface morphology of CuO films were analyzed using atomic force microscopy, AFM. Thin films of CuO have nanorods in its morphology structure. Optical constants, such as refractive ( n ) and absorption ( k ) indices of the prepared film were determined using spectrophotometric measurements. Hole mobility of CuO nanorods was deduced at a certain characterized frequency, for the first time for CuO, using the well known Drude equation. Optical transition type was found to be direct allowed with energy of 2.78 eV. From optical constants analysis for CuO films, the real ( ɛ 1 ) and imaginary ( ɛ 2 ) dielectric constants, optical conductivity and dissipation factor were also studied. Comparison of the obtained results with the available experimental data for previously published ones are also considered. [ABSTRACT FROM AUTHOR]

Films of indigo dye as organic semiconductors have been prepared with different thicknesses (462–885 nm) through thermal evaporation. X-ray diffraction shows a nanocrystalline structure for the films with crystallite size 10.5 ± 0.1 nm. AFM confirms the nanocrystalline structure of the prepared films. The optical properties of the indigo films have been investigated using Swanepoel's method. These films have 2 optical energy gaps (1.67 and 2.61 eV) and Urbach's energy of 0.22 eV. The refractive index has normal behavior to decrease with increasing the wavelength following the Cauchy formula and the single oscillator model. The oscillator energy E o and dispersion energy E d are 2.75 and 4.81 eV, respectively. The lattice dielectric constant ε L is 2.89 while the static dielectric constant ε s is 2.75. The linear/nonlinear optical susceptibility and nonlinear refractive index have similar behavior to increase with increasing the photon energy. • Thermal evaporated films of indigo have a nanocrystalline structure. • Indigo films have two indirect optical transitions. • The optical properties of the indigo films are thickness independent. • The nonlinear refractive index and linear/nonlinear optical susceptibility increase with the photon energy. [ABSTRACT FROM AUTHOR]

Structural and optical properties as a function of film thickness have been studied for the thermally evaporated cadmium iodide (CdI 2 ) films. According to XRD structure, the thickness of investigated films extends from 272 to 696 nm, showing hexagonal structure and good c -axis alignment normal to glass substrate plane. Both of crystallite size and lattice strain have been determined in terms of Voight method of the main peak. The optical constants, refractive index ( n ), and extinction coefficient ( k ) have been determined using envelope method. The optical absorption data indicates an allowed direct inter – band transition near the absorption edge with an optical energy gap that decreases continuously from 3.572 to 3.767 eV. Both of optical constants and energy gap show thickness dependence that can be explained in terms of structure parameters, crystallite size, and lattice strain. [ABSTRACT FROM AUTHOR]

Flower like 2,3-naphthalocyanine (NC) nanostructures thin films was successfully obtained by thermal evaporation technique under certain conditions. The surface morphology of NC thin films was studied by using scanning electron microscopy (SEM). The particle size distribution was recorded using particle size analyzer (PSA) which shows the average grain size of about 34 nm. The energy band model was applied to NC films and the type of the optical transitions responsible for optical absorption was found to be direct and has the value of 1.47 eV. The AC conductivity and dielectric properties of the films were investigated in the frequency range 50 Hz–100 kHz and in the temperature range 293–363 K. The activation energy for alternating current mechanism decreases with increasing frequency which confirms the hopping conduction as a dominant mechanism. The capacitance–frequency characteristics of nano-crystalline NC based heterojunctions were investigated under dark and illumination conditions in the range 3.6–100 mW/cm 2 . The increase in the capacitance of the device is interpreted to the space charge polarization induced by the increasing number of photo-generated carriers. Moreover, the fabricated heterojunctions are more sensitive to light, proposing them as a good candidate as a photodiode and/or capacitance sensor for optoelectronic applications in modern electronic industry. [ABSTRACT FROM AUTHOR]

Dye-sensitized solar cell (DSSC) was fabricated by using 2′,7′-dichlorofluorescein as an organic dye sensitizer (metal free dye). A FTO/titanium dioxide (TiO 2 ) electrode was dipped in a solution of 2′,7′-dichlorofluorescein and covered with another FTO electrode to form dye-sensitized solar cell. Using dyes in the fabrication of solar cells increases the efficiency of the solar cell. The photovoltaic and impedance spectroscopy properties of the solar cell were investigated. A beam of light of different intensity was focused on the surface of the DSSC to measure the open circuit voltage, the short circuit current, the output power and the fill factor. The capacitance–voltage, the conductance–voltage, the series resistance–voltage characteristics of the solar cell were measured in a wide range of frequency for the first time for DSSC applications. Owing to the injection of electrons from the FTO electrode into TiO 2 , the capacitance–voltage characteristic shows the behavior from the (+ve) to (−ve) capacitance. The photovoltaic of the DSSC can be improved using various organic semiconductors. Photons striking the dye with enough energy to be absorbed create an excited state of the dye, from which an electron can be “injected” directly into the conduction band of the TiO 2 From there it moves by diffusion to the clear anode on top. [ABSTRACT FROM AUTHOR]

Highlights: [•] B3LYP as well as FTIR were utilized to analyze MR. [•] Vibrational assignments for MR were aided at B3LYP/6-311G(d,p). [•] MR has a high dipole moment (7.2Debye) and HOMO/LUMO energy gap (3.5eV). [•] MR is a promising structure for optoelectronic devices as solar cells. [Copyright &y& Elsevier]