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Herein, we are reporting, for the first time, a microwave-assisted synthesis of lead iodide (PbI2) nanosheets (NSs) with codoping of Zn and Mn, confirmed by SEM/EDX. In the co-doping Mn concentration was kept at a constant level (i.e. 15 %) while Zn concentration was varied from 1 wt.% to 10 wt.%. The morphological analysis confirming presence of the dopant was done through SEM/EDX. The single phase and polytypic nature of NSs were established by XRD and FT-Raman examinations. Homogeneous doping of Mn and Zn in prepared PbI2 NSs was confirmed by SEM mapping analysis. The dielectric and electrical properties were measured by preparing a compact pellet of NSs at 49820 Pa pressure. The dielectric constant and electrical conductivity were enhanced by Zn:Mn co-doping in PbI2. The radiation activity was tested by cesium-137 (137Cs) radioactive source and its increase resulting from the doping was observed. The enhanced properties suggest that the prepared NSs may be useful in electro-optic and radiation detection device applications. [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]

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]

Herein, we report a successful development of nano-scale pure and Al and Mn co-doped PbI2 using facile microwaveassisted route. Structural study was done through X-ray diffraction analysis of grain size, dislocation density and lattice strain. The crystallite size was found to vary from 28 nm to 40 nm due to Al:Mn co-doping in PbI2. The presence of various vibrational modes was confirmed by FT-IR spectroscopy and red shifting was observed in peak positions compared to the bulk. Surface morphology, examined using a scanning electron microscope, confirmed the formation of single crystal nanosheets of a thickness in the range of 10 nm to 30 nm. The single crystal nanosheets were found to be transformed to large area nanosheets due to the doping. Enhancement in dielectric constant from ~7.5 to 11 was observed with increasing Al doping concentration. Linear attenuation coefficient was calculated and showed the enhancement of blocking gamma rays with increasing doping concentration. Its value was found to increase from 7.5 to 12.8 with the doping. The results suggest that the synthesized nanostructures can be used for detection and absorption of gamma rays emitted by 137Cs and 241Am sources. [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]

• 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]

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 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 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]

[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]

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]

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]

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]

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]

Abstract: The paper describes the structural and optical properties of CuSe thin films. X-ray diffraction pattern indicates that CuSe thin film has an amorphous structure. Transmittance T(λ) and reflectance R(λ) measurements in the wavelength range (300–1700nm) were used to calculate the refractive index n(λ), the absorption index and the optical dispersion parameters according to Wemple and Didomenico WDD model. The dispersion curve of the refractive index shows an anomalous dispersion in the absorption region and a normal dispersion in the transparent region. The optical bandgap has been estimated and confirmed by four different methods. The value for the direct bandgap for the as-deposited CuSe thin film approximately equals 2.7eV. The Raman spectroscopy was used to identify and quantify the individual phases presented in the CuSe films. [ABSTRACT FROM AUTHOR]

• Carmine dye-doped PVA polymeric composite films were prepared by solution casting method. • Structural analysis, optical parameters, dielectric properties, and AC electrical conductivity are measured and analyzed for carmine dye-doped PVA films. • The bandgap of PVA is reduced from 5.16 eV to 1.65 eV by the addition of carmine dye, and the refractive index increased up to 8. • The optical conductivity of carmine dye/PVA films classified into different stages according to the incident photon energy. • The normalized power decreased with increasing the carmine contents in PVA, and hence, these films are suitable CUT-OFF laser filters. Polyvinyl alcohol (PVA)/carmine dye polymeric composite films are prepared by a solution casting method. Pure PVA, 0.11 wt% carmine dye/PVA, 0.55 wt% carmine dye/PVA, 1.11 wt% carmine dye/PVA, 5.5 wt% carmine dye/PVA, 11.11 wt% carmine dye/PVA and 27.775 wt% carmine dye/PVA have a semi-crystalline structure. The transmission spectrum shows that the light is blocked till 600 nm for 27.775 wt% carmine dye/PVA composite films. The transmittance for the composite 27.775 wt% carmine/PVA is reduced to 61%. The absorption bands and band edges were shifted due to the increase of carmine dye percentage in the PVA matrix. The direct bandgap decreased from 5.16 to 1.65 eV as the carmine dye percentage increased.The indirect band gap decreased from 4.75 to 0.99 eV. The refractive index is strongly dependent on the amount of carmine dye on PVA, and the refractive index increased up to 8. The optical conductivity of PVA/carmine dye composites was divided into different stages according to the photon energy. The highest values of the dielectric loss for PVA/carmine dye composites were found at the lowest frequency (100 Hz). PVA/carmine dye composite films are promising standing up filters for laser power attenuation and optoelectronic devices. [ABSTRACT FROM AUTHOR]

A novel 6-butyl-3-[(4-chlorophenyl)diazenyl]-4-hydroxy-2H-pyrano[3,2-c] quinoline-2,5(6 H)-dione (dye 2) was effectively synthesized. The structure of (dye 2) has been set up using its accurate spectral and elemental analysis statistics. X-ray diffraction (XRD) analysis exhibited that (dye 2) has a polycrystalline nature. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) were utilized. Optical parameters, as well as absorption index of (dye 2), were calculated using diffused reflectance wavelength measurements range 200–2300 nm. The bandgap in optics was determined by applying the Kubelka–Munk theory. Two optical band gap values (2.57 and 2.33 eV) were obtained. The first value (2.57 eV) is responsible for the direct transition while the other value (2.33 eV) is responsible for the indirect bandgap. AC fields were primarily utilized to calculate and interpret both AC electrical conductivity, the dielectric constant, and the dielectric loss. Finally (dye 2) turns out to be efficiently material and may act as a novel solar cell window due to its high bandgap. Image 1 • A novel (Dye 2) was effectively synthesized as a new organic semiconductor. • BCDHPQD has a polycrystalline nature with a triclinic and with space group (P1). • Two values of the optical band gap (2.57 and 2.33 eV) were obtained. • AC electrical conductivity, dielectric constant and dielectric loss were measured and analyzed. • Dye 2 acts as a novel solar cell window layer due to their high band gap. [ABSTRACT FROM AUTHOR]

Acid fuchsin is a new organic semiconductor. The results of XRD measurements confirmed that acid fuchsin is polycrystalline in nature with a triclinic crystal structure with the P1 space group. The absorption index and the optical band gap transition of AF powder were calculated from the optical diffused reflectance (ODR). The direct, as well as the indirect band gaps, were calculated. These values of the energy band gaps for acid fuchsin enhance the light absorption and make it a suitable material to be applied in photovoltaic devices. The DC electrical conductivity of acid fuchsin was investigated in the temperature range 289–373 K. The AC electrical conductivity was discussed in terms of charge carrier hopping motions mechanism. Both the ε 1 and ε 2 which represent dielectric constant and dielectric loss, respectively, have been studied. Acid fuchsin can be used in organic devices as a new organic semiconductor. • Acid fuchsin is a new organic semiconductor with a triclinic crystal structure with the P1 space group. • The direct, as well as the indirect band gaps, were calculated for acid fuchsin. • The DC electrical conductivity of Acid fuchsin showed semiconducting behavior over a wide scale of temperature. • The AC electrical conductivity was discussed in terms of charge carrier hopping motions mechanism. • Acid fuchsin is suitable for organic LED, and photovoltaic/solar cell devices. [ABSTRACT FROM AUTHOR]

The basic component of optoelectronics technology is the optical filter, particularly the laser cut-off filter. Within this study, casting technique used to prepare polymeric composite film of (Eosin Yellow dye doped poly(vinyl alcohol) (EY/PVA)) for optical filter. This research has been performed on the XRD scan, UV-Vis-NIR and electrical spectroscopic analysis of EY/PVA films. XRD histogram shows reduction of composite films crystallinity. The transmittance of the films reduced as the dye content increases. A significant reduction in the composite's bandgap with Eosin Y doping is observed owing to the interactions between the functional group of the dye molecule and the hydroxide group in the PVA polymer matrix. Higher content of EY/PVA films (10 and 25) wt% can completely block incident light from 200 nm to 630 nm, which emphasizes the composite's strong potential as an effective optical filter. The optical limiting for EY/PVA films was tested with He-Ne laser beam source at the wavelength of 632.8 nm. It demonstrated the best possible optical limit behavior at high dyes content. The frequency dependence was evaluated on the AC electrical conductivity, dielectric constant, and dielectric loss were analyzed. The studied showed an improvement of the electrical conductivity and dielectric properties with increasing the EY-doping. The samples are ideal for the use of optical limits in CUT-OFF selective laser filters, solar cell, and variety of applications in industrial, electronics, pharmaceutical, medical, and related industries.applications. • Novel wide-scale CUT-OFF filter based on PVA doped Eosin Yellow dye films were designed and characterized. • PVA/ EY films were characterized by using XRD, FTIR, UV-Vis-NIR spectroscopy, dielectric spectroscopy, and optical limiting. • PVA/EY composites can be described by the electrostatic interaction between the PVA chains and the molecules of EY dye. • PVA/EY films showed a large-scale CUT-OFF laser filter inside the total spectrum. • Our designed filter is a unique polymeric composite film for optoelectronic and laser applications. [ABSTRACT FROM AUTHOR]

Abstract: The dielectric relaxation and alternating current mechanisms of nano-crystalline p-ZnGa2Te4/n-Si heterojunction diode (HJD) were investigated by complex impedance spectroscopy over a wide range of temperature (297–473K) and a frequency range (42Hz–5MHz). The bulk resistance as well as the bulk capacitance were found to increase with increasing temperature. The dc conductivity exhibits a typical Arrhenius behavior. The electrical activation energy was determined to be (0.28eV). The ac conductivity spectrum was found to obey Jonscher''s universal power law. The frequency exponent decreases slightly with increasing temperature. The temperature dependence of ac conductivity can be reasonably interpreted in terms of the correlated barrier hopping (CBH) model. The dielectric constant and dielectric loss were found to decrease with increasing frequency and to increase with increasing temperature. The mean value of the exponent decreases with increasing temperature. The dielectric analysis is described by non-Debye type behavior. [Copyright &y& Elsevier]

In this study, the AC impedance measurements have been used to characterize the monocrystalline silicon solar cell device under dark and illumination conditions. AC impedance measurements in the illuminated conditions are analyzed to identify the electronic behavior through equivalent AC circuit representation in terms of lumped parameters obtained by fitting the measured impedance data. The angle impedance phase increases from negative to positive values with increasing illumination conditions. The real part Z′ of the complex impedance value is typically higher at the dark light in the low-frequency region. It decreases gradually with increasing frequency reaching a plateau demonstrating independence on illumination at high frequencies. Nyquist plots exhibited a semicircle associated with the bulk single-crystalline body, and an additional spike is distinguishable at high frequency. The AC electrical conductivity is changed under dark and illumination conditions. Finally, the studied solar cell shows a highly sensitive light impedance response suggesting its suitability for use in photosensor applications. • Impedance Spectroscopy of monocrystalline silicon solar cells in dark and illumination conditions was studied and analyzed. •Nyquist plots and its related electronic circuits were described. •This device showed a purely capacitive to an inductive phase transition. •This device showed a highly sensitive to the light intensity. •Monocrystalline silicon solar is a suitable candidate for photosensor applications. [ABSTRACT FROM AUTHOR]

Polymethyl methacrylate with Safranin O dye samples has been prepared using the several-weight percentage of the dye varying from 0.185 to 7.407 wt % of Safranin O. We have examined their structure, optical, dielectric and optical limiting properties. The preparation has been done utilizing a fast and simple method, casting technique, where both the polymer and the dye were solved in chloroform. The characterization of the structure has been achieved using XRD where the polymeric composites samples displayed a noncrystalline hump that supports the amorphous structure of the studied films. Spectroscopy measurements have been exhausted to approximate the spectral absorption estimations of the samples like absorbance, transmittance as well as the calculations of the index of absorption (k), and optical transition bandgap (E g). The results indicate that the optical parameters alter by increasing the concentrations of the doping dye. From the obtained values of E g , two optical transitions (direct and indirect) are possible for these composites. According to the applied models in the polymeric materials field, dielectric characterizations have been done and their parameters have been measured. We have studied the optical limiting characteristics of the samples with several concentrations of the dye using different laser sources of He–Ne working at 632.8 nm and 533 nm. The result showed an evident optical limiting impact on the films. Utilizing this optical limiting impact, the samples under consideration are appropriate to be applied in the applications of solar cell and CUT-OFF laser filters and laser power attenuation. [ABSTRACT FROM AUTHOR]

In this work, a solution casting method was used to prepare the PbI 2 /PMMA nanocomposites films. XRD was used to achieve structural characterizations. An increase in an amorphous hump was showed after doping with PbI 2 nanostructured. The spectra of FTIR were evaluated between (4000–400 cm−1). The carbonyl stretch band at 1754 cm−1 shifted to higher wavenumber shows the electrostatic interaction between PbI 2 and the oxygen of the carbonyl group. Nanocomposites films were identified by scanning electron microscope. The optical UV–Vis–NIR aspects of the nanocomposite films were determined. Increasing the concentration of PbI 2 in the investigated samples caused the energy gap to be decreased. Such adjustments in the optical characteristics of the PMMA sample are because of the interaction between the PMMA matrix and the PbI 2 nanoparticles. AC electrical conductivity and dielectric properties were studied at room temperature. The dielectric constant increases with increasing the concentration of PbI 2. Optical limiting was evaluated and investigated for PbI 2 /PMMA nanocomposites and the He–Ne and green lasers power was reduced by increasing PbI 2 contents. The PbI 2 /PMMA nanocomposites are promising candidates for solar cells, electronic/optoelectronic devices, and CUT-OFF laser filters. • PbI 2 /PMMA nanocomposites were prepared by casting method. • The addition of PbI 2 into PMMA matrix reduce the optical bandgap energy. • AC electrical conductivity rises with frequency and PbI 2 dopant levels. • PbI 2 /PMMA nanocomposites showed laser power attenuation. • The designed polymeric composite filter can be used for optoelectronic and radiation detection. [ABSTRACT FROM AUTHOR]

Methyl violet-10B (MV-10B) nanostructured thin films are deposited onto highly cleaned conductive fluorine-doped SnO 2 substrates (FTO) using cost-effective spin coating method for the first time. The structure measurements including both X-ray diffraction and atomic force microscopy are used to describe the structure analysis and surface morphology of the studied films. Optical linearity and nonlinearity of MV-10B have been studied of different thicknesses. XRD of FTO is crystalline with different peaks and MV-10B thin film exhibit amorphous behavior. Indices of absorption, refractive, absorption coefficient and linear optical susceptibility are calculated and analyzed in details. Analysis of absorption coefficient gives the type of bandgap transition and two band gaps are established as follows: one at the higher energy which is related to FTO layer/glass and the other is laid at the lower energy which related to MV-10B and the film thickness is affected slightly. The parameter of nonlinear optical of these films such as nonlinear refractive index n (2) and nonlinear optical susceptibility χ (3) was calculated and analyzed. The studied nanostructure MV-10B thin films can be also in the optical limiting behavior of low/medium power of He–Ne/green lasers for controlling the laser beam power. Image 1016 • Methyl violet-10B (MV-10B) nanostructured thin films were deposited onto (FTO). • Optical Linearity and nonlinearity of MV-10B have been studied at different thicknesses. • Investigation of absorption coefficient gives the type of band gap and two gaps are established. • Nonlinear optics of these films show good values in comparison with other materials. • Nanostructure MV-10B thin films can be used as an optical limiting for He–Ne/green lasers. [ABSTRACT FROM AUTHOR]

Synthesis of NiO nanostructures in presence of different concentrations of citric acid (CA) was achieved through flash combustion technique. The NiO nanostructures formation was confirmed through X-ray diffraction analysis. At low concentrations of CA no extra peak was observed in XRD patterns, however when the CA concentration was raised to 5 and 10 g, two new extra peaks appeared at 44.6° and 51.9° which may be attributed to the presence of C. The crystallite size was noticed to reduce from 29 to 18 nm with increase in the CA concentration. All observed Raman bands were noticed to be shifted owing to the quantum size effect. EDX and SEM mapping confirm the existence of C. SEM images confirm the cubic nanocrystalline morphology for 0.5 g CA:NiO, however with increasing CA concentration a drastic change in morphology, i.e. from nanocrystals to extended nanosheets, was observed. The energy gap values were determined using Kubelka-Munk theory and found in range of 3.5–4.0 eV. An additional energy gap ∼2 eV was also noticed at higher CA concentration. The values of relative permittivity, ε r ′ , were found in the range of 18–110 for CA concentration upto 5g, however, at 10.0 g CA its value was found to be order of 104 at 2 × 105 Hz. [ABSTRACT FROM AUTHOR]

Abstract The linear and non-linear optical properties of pentacene films were measured at 300 K in the UV–vis-NIR region depending on the measurements of both transmission and reflection. The results of XRD pattern demonstrated the presence of polycrystalline nature as well as the nanostructure characteristics. The mean crystallite size and the microstrain parameters of pentacene were acquired to be 19.15 nm and 6.05 × 10−5, respectively. The type of the optical transition is directly allowed with optical band gaps of 1.57, 2.58 and 3.60 eV. The optical dispersion parameters were acquired and studied as a function of wavelength. The well-known spectroscopic technique is utilized to describe and evaluate the nonlinear optical susceptibilities due to its correlation with the linear refractive index. The spectral behavior of hyperpolarizability and the second order refractive index of pentacene films was achieved. The results emphasize the viability of creating photodetector devices based-pentacene films. The results utilized the studied material as nonlinear optical media because of its remarkable characteristics. [ABSTRACT FROM AUTHOR]

Abstract In this study, we investigated the monocrystal growth and characteristics of pure and methyl violet (MV) dyed zinc(tris) thiourea sulfate (ZTS) large size single crystals. The morphology of ZTS was modified in the presence of MV dye. The crystals were crushed for a finite time to obtain powders for X-ray diffraction analysis and the lattice parameters were determined. The crystals were analyzed based on Fourier transform-Raman spectroscopy measurements and the vibrational modes were identified. Some extra vibrational modes were observed due to the presence of the MV dye. Ultraviolet–visible–near infrared optical absorbance measurements were recorded and the band gap was calculated. A large band gap ∼4.31 eV was obtained for the ZTS crystals, which supports their possible application in electro-optic devices. Two absorption bands at around 584 nm (sharp) and ∼362 nm (broad) were also observed in the dyed crystals but not in the pure crystals, thereby indicating the interaction between the dye and ZTS. Photoluminescence (PL) emission studies were conducted at an excitation wavelength of 360 nm. PL emission peaks were observed at ∼433 nm in the pure crystals, and at ∼421 and 444 ± 5 nm in the dyed crystals. Differential scanning calorimetry demonstrated the increased melting temperature of ZTS in the presence of the dye. The dielectric constant, ac electrical conductivity, and mechanical strength were higher for the dyed crystals. Our results suggest that the dyed crystals may be more suitable for applications in opto-electronic devices compared with the pure crystals. Graphical abstract Image 1 Highlights • Zinc(tris) thiourea sulfate (ZTS) crystals grown with methyl violet (MV). • Structural and vibrational analyses confirmed the presence of MV dye. • Two absorption bands detected at ∼362 nm and ∼584 nm in MV dyed crystals. • Optical band gap values ranged from 4.29 to 4.33 eV. • Photoluminescence, dielectric constant, and mechanical properties enhanced by MV. [ABSTRACT FROM AUTHOR]

Large size single crystals of Diiodo-bis(carbamide)-zinc(II) [ZnI 2 . 2[CO(NH 2 ) 2 ] were grown successfully for the first time by slow evaporation techniques at room temperature within the evaporation time of two weeks. The single phase and high crystalline nature of the grown crystals was confirmed by X-ray diffraction analysis. Quantum chemically the geometrical parameters were found in good correlation with experimental values calculated at B3LYP/6-31G* (LANL2DZ), B2LYPD/6-31G* (LANL2DZ), M062X/6-31G* (LANL2DZ) and MP2/6-31G* (LANL2DZ) level of theories. Additionally, the experimental vibrational modes also have shown a good agreement with calculated ones. The optical transparency and band gap were calculated and found to be ∼80% and 4.706 eV, respectively. The calculated value of HOMO-LUMO gap was found in correlation with experimental energy gap. The electronic properties were investigated by shedding light on the frontier molecular orbitals, partial density of states (PDOS), and total density of states (TDOS). The mechanical and dielectric studies show that the grown crystals possess quite good mechanical strength and dielectric constant. The dielectric loss revealed that the grown crystal contains low defects. The total ac electrical conductivity was increased with frequency and the frequency components confirm the sudden hoping mechanism in the grown crystal. [ABSTRACT FROM AUTHOR]

In the present investigation, a low-cost and high-operational sol-gel spin coating technique for preparing undoped and various Europium (Er)-doped CdO films of molar percentages of 1%, 5%, 10%, and 15% were considered. Using X-ray diffraction, the polycrystalline nature reveals two preferred orientations of (111) and (200). The mean crystallite size was evaluated and increased from 20.95 to 49.37 nm using the well-known Scherer's formula by increasing the Eu- dopant content. The atomic force microscopy images indicate a homogeneity of a granular distribution deteriorated with Eu-content. The root means square roughness value was evaluated and increased from 4.1 nm to 284 nm with Eu-doping. High transmission of approximately 80% in the visible region spectrum was recorded. The optical band gaps are increased from 2.2 to 2.46 eV from the undoped and various Eu-content %. A relationship between the Eu- content % for CdO films and the optical parameters was discussed to support the availability of the device for optoelectronic applications. [Display omitted] • Films of Eu-doped CdO were produced through a sol-gel spin coating technique. • The effect of Eu-doping on the enhancement of CdO properties was investigated. • The optical constants were computed by the Kramer-Kronig method. • The energy band gap is direct allowed and influenced by Eu- doping. • The results confirm the capability of Eu-CdO for optoelectronic devices. [ABSTRACT FROM AUTHOR]

Metal-sulfides semiconductor nanosheets are talented entrant to be applied in electro-optic devices. Hence, the synthesis of PbS nanosheets is achieved in the current work using a simple route. The synthesized nanosheets were characterized by X-ray diffraction (XRD), FT-Raman, scanning electron microscope (SEM), UV-Visible, Photoluminescence (PL) and impedance spectroscopy techniques. XRD pattern and Raman spectrum confirms the formation of crystalline structure of PbS nanosheets. SEM study shows that the synthesized PbS is well defined nanosheets of <5 nm thicknesses. The absorption band edge is found to be remarkably blue shifted in nanosheets compare to bulk. The energy gap is calculated to be 1.16 eV which is about 3 times superior than the bulk value (0.41 eV). The enhancement of band gap indicates the occurrence of quantum confinement effect in PbS nanosheets. A strong violet emission band at ∼405 nm is observed in PL spectrum which is assigned to electrons transition from conduction-band edge to holes, ensnared at interstitial Pb 2+ sites. [ABSTRACT FROM AUTHOR]

Sulfamic acid is a potential material that exhibits excellent optical properties. A good quality, pure and dysprosium (Dy 3+ ) doped (2.5 and 5 mol %) Sulfamic acid (SA) single crystals were grown successfully by slow cooling method. Structural study revealed a slight change in its lattice parameters and volume, suggesting the successful incorporation of Dy 3+ in crystal system. The existence of dysprosium in the system was also confirmed. Presence of various vibrational modes was confirmed. Optical transparency was found to have a significant effect with variation in the doping concentration. Furthermore, a marked enhancement in its mechanical parameters with doping was also identified by nanoindentation technique. Etching study was also performed on the grown crystals to study the etch-pit formation and growth mechanism. Effect of doping on the thermal stability was analysed. All the results were compared and discussed in detail to get insight of the effect of doping concentration on Sulfamic acid crystal. [ABSTRACT FROM AUTHOR]

The nonlinear optical single crystals of pure and Ni 2+ doped potassium dihydrogen phosphate (KDP) were successfully grown by slow evaporation solution growth technique. The effects of the addition of Ni 2+ with different molar concentration have been studied by powder X-ray diffraction, FT-Raman, second harmonic generation, microscopic and dielectric studies. Its crystallinity was assessed by the FT-Raman technique and its surface, structural imperfections were recorded using high resolution microscope, which clearly reveals that the doping is showing considerable effect on the samples. The SHG measurements also carried out on pure and doped samples, which reveal the relative SHG efficiency has been enhanced due to doping. The optical activities were studied by UV–vis-NIR technique and reveals high optical transparency in doped samples. The remarkable enhancement in mechanical strength was observed due to doping. The enhanced dielectric constant and low dielectric loss confirms that the grown crystals with doping are superior to pure crystals and may be used in optoelectronic devices. [ABSTRACT FROM AUTHOR]

Nanoparticles (NPs) of ZnS with different weights of CTAB (cetyltrimethylammonium bromide) have been successfully synthesized by microwave assisted co-precipitation method. The x-ray diffraction patterns exhibited cubic phase crystal structure with crystallite size of ~3 nm. The morphological studies of the grown samples have been investigated using Scanning electron microscopy (SEM). Diffused reflectance spectra were employed to calculate energy gaps for prepared samples using Kubelka-Munk theory, and the values were in the range of 3.59–3.64 eV. Raman spectra confirm the synthesis of ZnS nanoparticles at all CTAB contents and it contains two major Raman modes at ~264 and 346 cm−1 related to TO and LO modes which are shifted to lower wavenumbers indicates phonon confinement in the final products. The variations in the dielectric constant, ε' and dielectric loss were calculated. The values of ε' is higher in the low frequencies, whereas it is found almost stable between 1 MHz and 5 MHz and is increasing at higher frequencies. The dielectric study reveals that the samples possess high values of dielectric constant which are between 27 and 35 and low loss values. The electrical conductivity is noticed to be increased with increasing the frequency and also noticed to be varied with varying the CTAB content in ZnS. The synthesized low dimension NPs, high energy gap and dielectric constant and low loss values signifies that the prepared NPs are suitable for optoelectronics. [ABSTRACT FROM AUTHOR]

• Bulk size (18 × 12 × 12 mm3) crystal of L-alanine has been grown by Seed supported solution growth. • Energy gap was calculated via Tauc's rule and found to be lie between 5.26 and 5.36 eV. • Grown crystal is of high transparency of 80 and 89% make it useful in optoelectronic devices. • Mechanical strength values of different faces of L-alanine crystal is noted ~30, 48, 50 and 65 kg/mm2. • Dielectric and electrical properties are inspected at four different faces and discussed. The large growth of L-alanine single crystal (size = ~18 × 12 × 12 mm3) was achieved by seed supported solution growth technique for the first time. The structure and vibrational modes of the crystal were confirmed by X-ray diffraction (XRD) and FT-Raman analyses, respectively. UV–Vis-NIR absorbance and transmittance measurements were carried out and Tauc's rule is used to calculate energy gap for the grown crystal and found to be lie within 5.26–5.36 eV. The grown crystal is of high transparency between 80 and 89%, and the energy gap makes it useful for optoelectronic devices. The mechanical strength and chemical etching studies were also carried out and discussed. The present load independent hardness values along different faces of L-alanine crystal are noted ~30, 48, 50 and 65 kg/mm2, respectively, which indicates that (2 0 2) face showing higher hardness value compare to all the faces. The etch pit density was observed to be ~4 × 102/cm2. Furthermore, dielectric and electrical studies were also done. The facile and low-cost growth, high optical transparency, energy gap, microhardness, dielectric and electrical of the grown crystal indicates that it is suitable for optoelectronic devices. [ABSTRACT FROM AUTHOR]

• SnBr 2 /PVA polymer electrolytes were characterized using X-ray diffraction, FTIR, optical properties, and dielectric spectroscopy. • XRD, FT-IR, and SEM reveal that the interactions with SnBr 2 salt altered the PVA structure. • The addition of SnBr 2 into the PVA matrix reduces the optical band gap energy, directly and indirectly. • AC electrical conductivity rises with frequency and SnBr 2 salt levels. • Our designed filter is a unique polymer electrolytes films for optoelectronic and applications with electrochemical devices. A polymer electrolyte of PVA (Polyvinyl alcohol) doped with Tin (II) Bromide (SnBr 2) at different weight ratios was synthesized by casting technique. The structure analysis of the composites was displayed by XRD (X-ray diffraction) and F.T. (Fourier transform)-IR techniques, which showed the decrement in the crystallinity with the argument of SnBr 2 concentration and functional interaction between SnBr 2 and PVA, respectively. The absorbance (A bs.) and transmittance (T %) in the range of wavelength 190−2500 nm were documented through the UV–vis spectrophotometer to research the influence of SnBr 2 on the optical performance of PVA. The incorporation between SnBr 2 and the main chain of the PVA matrix brings out a notable change in the optical properties of the polymer electrolytes. The optical band gap, refractive index (n), extinction coefficient (k), the real and imaginary parts of dielectric constant (ε r and ε i) as well as optical conductivity (σ o p) exposed a clear dependence on the SnBr 2 content. Moreover, the dependence of dielectric properties on the contents of SnBr 2 has been studied in the range of frequency from 100 Hz to 1 MHz. The conduction mechanism is mainly correlated Barrier Hopping (CBH) model. SnBr 2 /(PVA) polymeric solid electrolyte can be used for electronic and optoelectronic and electrochemical devices. [ABSTRACT FROM AUTHOR]

The fabrication of Dy:PbI 2 /glass (Dy = 0.0 to 0.8 wt%) films were performed using a spin coating process. X-ray diffraction confirmed the formation of monophasic hexagonal films growth along (001) planes. The estimated size of crystallites was noticed to be in the range of 16–22 nm. Scanning electron microscopy (SEM) study indicates the strong effect of Dy content on the morphology of film surface and the grown grain sizes were in 13–70 nm range. EDX/SEM e-mapping approves the existence of Dy in PbI 2 films. The transparency of grown films was found to be in the range of 60 to 87%. Optical bandgap was estimated to be 2.21 eV–2.35 eV range. The values of index of refraction was found in 2–8 range. The constant of dielectric values was noted in the range of 5–50 and showed an enhancement by Dy doping. The value of χ(1) was noticed to be increased by Dy content doping and found in the range of 0.2–7. The χ(3) values were calculated in the range of 3.4 × 10−13 to 3800 × 10−10 esu. The n2 values were noted to be in the range of 6 × 10−12 to 1.5 × 10−6 esu. The remarkable enhancement on nonlinear values proposed the grown Dy:PbI 2 /glass films for opto-nonlinear applications. • Nanostructured thin films of Dy:PbI 2 /glass has been low-costly fabricated for the first time. • Mono-phase and high crystallinity of films was approved by XRD/Raman analysis. • SEM study revealed low dimension nanoparticles formation. • The optical band gap was calculated to be in range of 2.21 eV to 2.35 eV. • An increase in χ(3) values were observed from 5 × 10−10 to 4000 × 10−10 esu. [ABSTRACT FROM AUTHOR]