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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]

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, 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]

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]

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]

Highlights: [•] Optical and structural properties of the nano-matrix ZnO(1− x )SiO2( x ) are studied. [•] The optical band gaps for the studied nano-system are calculated. [•] Crystal structures of a nano-matrix and detailed crystal parameters are calculated. [ABSTRACT FROM AUTHOR]

Highlights: [•] Nano-pentacene thin film was prepared via thermal evaporation. [•] Optical constants and optical dispersion parameters were calculated. [•] The complex dielectric constant and the band gap were determined. [•] The optical conductivity σopt , (VELF) and (SELF) functions were calculated. [•] Pentacene is a good candidate for the organic thin film transistor. [Copyright &y& Elsevier]

Highlights: [•] The Al doped CdO were grown by sol–gel spin-coating. [•] Structural properties were studied by AFM. [•] Optical transmittance is decreased with increasing Al contents. [•] Optical band gaps and the width of localized states were calculated. [•] Al-doped CdO can be used in optoelectronic device applications. [Copyright &y& Elsevier]

• Halogens (X 2) adsorption on reduced graphene oxide (rGO) surface by DFT calculations. • Adsorption of X 2 on rGO surface stabilized by X 2 (lp)...π(C) and O(lp)...π(X 2) forces. • The charge transfer process through X 2 (lp)...π(C) stabilized in polar solvents. • Adsorption of X 2 on rGO surface tunes the optical properties through the intermediate state in the band gap region. In this work, we investigate the lone pair (lp)...π interaction for the halogens (X 2 =I 2 , Br 2 , Cl 2 , and F 2) binding to the rGO surface. Electronic and optical properties of rGO significantly tuned upon adsorption of halogen molecules, although the weak nature of (lp)...π forces. The structure and optical properties of rGO, rGOI 2 , rGOBr 2 , rGOCl 2 and rGOF 2 adducts were investigated by density functional theory (DFT) and time-dependent DFT (TD-DFT) method. Halogen molecules (X 2) stable structures were planer on rGO surface and stabilized by the lone pair X 2 (lp)...π(C) interactions. The surface oxygen atoms contributed to the stability by the O(lp)... π(X 2) charge transfer process. Bader analysis reveals significant charge transfer and bond length elongation for X 2 on rGO monolayer sheet in the order I 2 > Br 2 > Cl 2 > F 2. Surface adsorption of X 2 molecules on rGO surface tunes both band gap energy and optical properties. The TDOS and PDOS reveal that X 2 adsorption on rGO surface forms an intermediate states in band gap region, which decrease the energy values. These results are beneficial for photocatalysis and light harvesting applications. [ABSTRACT FROM AUTHOR]

The static refractive index n o of different types of materials, like semiconductors, insulators, oxides, thin-films, and glasses, has been reported in many publications in attempts to estimate how it can be correlated to the optical bandgap. Reviewing of the previous studies to correlate the optical refractive index and energy gap led to concluded that Reddy Ahmmed approximation was selected to develop a new realized form that can give a good fit to the experimental data and, hence, be used directly as an accurate formula in the theoretical studies. The obtained formula correlates the optical/static refractive index to the energy bandgap and the oxygen atom's electronegativity. Such a new relation has been used to calculate the refractive indices for more than 96 materials (elements/compounds) with a high agreement with the experimental data. • New empirical relation correlates the static refractive index to the optical bandedge. • Bandgap structure. • Empirical relation between the static refractive index to the optical bandgap/band edge. • Comparative study. • New empirical relation correlates the static refractive index and the optical bandgap/band edge. [ABSTRACT FROM AUTHOR]

The organic thin films of fluorescein dye were deposited on fluorine-doped tin oxide glass substrate by using low-cost spin coating technique. The surface of the deposited film was characterized by using AFM and X-ray diffraction spectroscopy, which shows that the film is uniform and amorphous. The spectrophotometric study was carried out at the wavelength range of 300–2500 nm. The spectral dependences of the linear refractive index and absorption index were found to decrease as the wavelength was increased. Tauc's plot study revealed that the film shows the direct transition and energy band gap values were found 1.75 eV and 3.55 eV for the thin film and the substrate, respectively. Optical constants were found nearly the same in the higher energy domain (1.0–4.5 eV). Spectroscopic method was employed to study the nonlinear optical susceptibility χ ( 3 ) . The deposited thin film is a promising optical system for new generation of optoelectronics. [ABSTRACT FROM AUTHOR]

Herein a good adherent film of PMMA doped with the various ratio of BG-dye deposited on optically flat FTO-substrates by using a well-controlled spin coating process. The average crystallite size and microstrain were determined by X-ray diffraction pattern analysis and were found to be 21.7219 nm and 0.0016, respectively, with a significant change with the amount of BG-dye doping in the matrix of PMMA film. Both linear and nonlinear optical characteristics, as well as their related parameters, were measured using a UV–Vis–NIR spectrophotometer. As a result of doping BG-dye molecules into the host PMMA matrix system, optical absorption studies revealed significant changes in optical characteristics. BG-dye doped PMMA film revealed impressive absorption bands in the range of 350–750 nm, depending on the degree of doping of BG-dye into the PMMA film. Another distinguished property is the attenuation of the complete absorption in the range of 552–688 nm and observed as a cut-off-absorbance. The point of the art of this contribution is the various applications for optical limitation systems like Cut-off filters and other related optical devices due to the remarkable optical features. The BG-dye doping influenced all optical metrics, including the absorption band, absorption edge, and direct and/or indirect energy band gap. The direct energy gap's first region is in the range of 1.77–1.97 eV, whereas the second is in the range of 2.68–2.82 eV, and the third is in the range of 3.67–4.09 eV. The indirectly allowed transitions are divided into two regions, the first of which is in the 1.74–1.82 eV range and the second of which is in the 3.69–3.98 eV range. The appearance of extra energy levels is confirmed by fluctuations in the optical band gap, which are aided by the influence of dopant concentration of BG-dye dopant wt.%. The ratio of BG-dye into the PMMA film is promising for the optical respective of the green light for the cut-off filter as well as optoelectronic device applications. [ABSTRACT FROM AUTHOR]

In this current research, polyvinyl alcohol (PVA)/polyethylene glycol (PEG)/methylcellulose (MC), (PVA-PEG-MC), (8:1:1) blend composite films reinforced with varying loadings of Eriochrome Black T dye were formed via a solution casting methodology. X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and Ultraviolet–visible (UV–vis) spectroscopy were applied to examine the influence of EBT dye packing on (PVA-PEG-MC) properties, especially optical ones. From XRD investigations, it became apparent that the incorporated EBT dye interrupted the crystallinity phase of the blend matrix. Furthermore, in the FTIR spectra, considerable band shifting and decreases in transmittance intensity for the doped samples were seen, which confirmed the development of the H-bond between the matrix and the dopant. The UV–Vis absorption and transmittance spectra are moved to longer wavelengths, suggesting the importance of these composites in light shielding devices. The indirect allowed transition was prominent in all studied samples, according to three effective approaches involving Tauc's equation, the ASF model, and the ε i − h ν plot, where increasing the addition of EBT dye resulted in a drop of two optical energy band gap (E g (1) i n d ) and (E g (2) i n d ) values. Tailing in the band gap was shown to follow the Urbach rule. Six distinct models were utilized to determine the approximate values of the linear refractive index (n) using the estimated gap energies values, where the mean (average) value of the refractive index for the pristine (PVA- PEG-MC) matrix was 2.082. In contrast, it was 2.28 for the EBT dye composite film. Additionally, several other optical parameters were identified, including the extinction coefficient (K) , optical dielectric parameters, energy loss functions for surfaces and volumes, optical and electrical conductivity. Nonlinear optical parameters χ (3) , χ (1) and n 2 were calculated and analyzed for the EBT dye/(PVA-PEG-MC) composite films under examination. The optical limiting features revealed that the high amount of EBT dye incorporated in the ternary (PVA- PEG-MC) blend matrix reduces the output and normalized power utilizing different wavelength laser sources, which is suitable for optical limiting and laser attenuation in optoelectronic instruments. The unique results in the current work suggest applications for EBT dye/(PVA-PEG-MC) composite films in linear and nonlinear optical systems. [ABSTRACT FROM AUTHOR]

[Display omitted] • The DGEBA epoxy dispersed 5CB liquid crystals (DED5CBLC) were prepared by dispersion method. • The 5CBLC fillers can be used to modify the properties of DGEBA epoxy. • Optical results of this study show that the band gap of a disc shape system can be tuned by varying the wt% 5CBLC filler. • The AC conductivity of the composites spreads with rising wt% 5CBLC fillers and frequency. The DGEBA: Diglycidyletherbisphenol A and Liquid Crystal (4′-Pentyl-4-Biphenylcarbonitrile (5CBLC)) have been used to fabricate the so-called DGEBA epoxy dispersed 5CB liquid crystals (DED5CBLC). The XRD study's findings suggest that 5CBLC fillers can be used to change the properties of DGEBA epoxy without significantly changing its structure. Results from optical measurements reveal that the amount of 5CBLC filler added to the new disc shape system can adjust the band gap. This provides a way to design disc shape systems with desired optical properties. A promising correlation exists between optical linear susceptibility, third nonlinear optical, and nonlinear refractive index with 5CBLC filler in the DGEBA epoxy matrix. This correlation is since all three of these properties are told to the electronic structure of the DGEBA epoxy matrix. AC-impedance and AC conductivity properties of DED5CBLC disc shape systems filled with various wt% CB molecules have been good for adding 5CBLC content and applied field frequency. The results show that the AC conductivity of the composite spreads with rising wt% 5CBLC filler content and frequency. The continuous Jonscher fitting theoretical curve can be used to characterize the relaxation process and predict the system's electrical properties at different frequencies. The shrink in impedance directs that the composite substance befalls more conductive. [ABSTRACT FROM AUTHOR]

• A new designed optical system based on g-carbon nitride doped poly(vinyl alcohol) prepared successfully. • X-ray diffraction (XRD) illustrates a uniform and semicrystalline structure in nature for the obtained samples. • Both direct and indirect bandgaps were calculated and analyzed. • The studied polymeric composites films are highly attenuated for the laser beam of 632.8 nm. • The designed g-C 3 N 4 /PVA composites can be extensively appropriate to the optoelectronic applications. Nanocomposites consisting of polyvinyl alcohol (PVA) and graphitic carbon nitride nanoparticles (g-C 3 N 4) were fabricated by solution casting technique. XRD has shown that the semicrystalline PVA structure is greatly affected by the incorporation of g-C 3 N 4 , which is confirmed by SEM images. Optical characteristics are investigated at room temperature within the wavelength range (200–1500 nm). The effect of g-C 3 N 4 content on the optical band gap was studied. The optical bandgaps, direct and indirect, of g-C 3 N 4 doped films, is lower than pristine PVA. Urbach's energy increased from 0.42 eV for PVA to 0.96 eV for 14.8 wt% g-C 3 N 4 doped film. The dielectric constant ε ′ , dielectric loss ε ″ , and AC electrical conductivity σ ac at RT as a function of frequency from 100 Hz to 1 MHz, and g-C 3 N 4 doping level were studied. The variation of σ ac with frequency was analyzed in view of Jonscher's universal power law. Adding g-C 3 N 4 appears to enhance the σ ac of the films to higher values that candidates them in semiconductors applications. The results optical limiting indicates that the samples doped with g-C 3 N 4 are highly attenuated for the laser beam of 638.2 nm. g-C 3 N 4 -doped PVA is a promising candidate for electronic and optoelectronic applications, especially the attenuation of laser power. [ABSTRACT FROM AUTHOR]

The spray pyrolysis, as a non-vacuum cost-effective technique was used to develop high-quality thin films of SnO 2 and Sb-doped SnO 2 on Soda-lime glass substrates as transparent conductive oxides (TCOs). The surface morphology of the thin films under study was checked by the atomic force microscope. The average particle size and surface roughness of SnO 2 and Sb-doped SnO 2 thin films mainly depend on the Sb doping level. The structural identification of the as-deposited thin films has been investigated by the X-ray diffraction technique (XRD). XRD patterns have confirmed that the as-deposited thin films have a nanocrystalline structure with the tetragonal phase for all thin-film samples. The optical distribution of the transmittance and absorbance has been studied in a wide range of the wavelength (200–2500 nm). The absorption coefficient, optical band gap, and refractive index have been obtained by using the Swanepoel model. The optoelectronic properties for the thin films under study have been evaluated as TCOs films for photovoltaic applications. The sheet resistance and optical conductivity also have been determined for the thin film under investigation depending on the Sb doping level. Image 1 • Conductive and transparent films can be obtained by cost-effective spray pyrolysis technique and abundant materials. • X-ray diffraction and atomic force microscope showed the nanocrystalline nature of the SnO 2 and Sb doped SnO 2 films. • The transmission, optical band and sheet resistance values confirm the use of these films as a conductive window layer. • The figure of merit values of these films showed a good opportunity to be applicable in thin-film solar cells. [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]

The casting aqueous solution technique was used to prepare Co: ZnO incorporated PVA nanocomposite polymer system films (CZO-PVA NCPSFs) with different wt % CZO nanopowders. Based on the Williamson-Hall equation, the values of crystallite sizes, lattice strains, dislocation densities, and stacking fault energies were found to be in the range of 27.13–72.59 nm, 4.08 × 10−5-1.63 × 10−3, 1.36 × 1015–1.89 × 1014 lines per m2 and 3.82 × 10−3-1.87 × 10−3 for the pure CZO nanopowders and 3.70 wt% CZO films, respectively. The first direct-band gap bowing parameter decreased from 5.773 eV for pure PVA to 3.117 eV for 3.70 wt% CZO. The second direct band gaps were observed at 2.741, 2.523, and 2.413 eV for the 1.85 wt% CZO, 2.78 wt% CZO, and 3.70 wt% CZO films, respectively. The first values of indirect band gaps were observed in the range of 4.708 eV for pure PVA to 3.931 eV for 3.70 wt% CZO films. The second indirect values were observed in the range of 1.651 eV for 0.18 wt% CZO to 0.599 eV for 3.70 wt% CZO films. The limiting effect of CZO-PVA NCPSFs was also affected by the doping concentration of CZO nanopowder. The values of R b , Q, and σ DC parameters were found to be in the range 7.08 × 107–3.89 × 108Ω, 9.03 × 10−11-6.03 × 10−11 F, and 5.755 × 10−8-1.047 × 10−8 S/m for pure PVA and 3.70 wt % CZO films. Our results provide valuable insights into designing and optimizing CZO-PVA NCPSFs for optical sensing electronic applications. • The Co: ZnO nanopowder was prepared by sol-gel method. • Solution casting was used to synthesize Co: ZnO incorporated PVA nanocomposite polymer system films (CZO-PVA NCPSFs). • CZO-PVA nanopowder fillers were studied for their optical, limiting effect, and dielectric characteristics. • The result corroborates dispersed CZO nanopowders forming in the PVA polymer matrix. • This fabricated material with excellent properties may be considered for optical-electronic applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • This research work pristine Bi 2 S 3 , Bi 2 S 3 :Cu2%, Bi 2 S 3 :La2%, and Bi 2 S 3 :Cu2%:La2% thin films were prepared by nebulizer spray pyrolysis. • The morphological studies using FESEM analysis showed the unformed distribution of small grains. • The optical absorbance spectra of the thin films were observed from the wavelength of 350 nm to 1000 nm. • films were subjected to analyzing U.V. photosensing properties. As a result, maximum responsivity (1.24 × 10−01 AW−1), detectivity (1.13 × 1010 Jones), and EQE (40%) were achieved for Bi 2 S 3 :Cu: La-sample. Nowadays, chalcogenide-based thin layers are proving a promising light-absorbing material with low cost and are technologically suitable for light to current conversion applications. In this study, for the first time, pristine Bi 2 S 3 , Bi 2 S 3 :Cu2%, Bi 2 S 3 :La2%, and Bi 2 S 3 :Cu2%:La2% thin films were prepared by nebulizer spray pyrolysis technique on a glass substrate at 300 °C. The obtained XRD pattern confirms the orthorhombic structure of Bi 2 S 3 and possesses a maximum crystallite size of 38 nm for Bi 2 S 3 :Cu: La co-doped sample. Images taken with a FESEM analysis showed the unformed distribution of round shaped grains without any cracks and co-doping leads to the development of slight cluster formation. The optical absorbance spectra of the thin films were observed from the wavelength of 350 nm to 1000 nm, and the co doping process highly strengthen the optical absorbance, which is prerequisite for an efficient photodetector. A lower band gap value of 1.7 eV is achieved for Bi 2 S 3 : Cu: La thin film. From PL studies, defect emission bands around ∼325 and 525 nm related to band edge emission and sulfur vacancies are obtained. Further, UV photosensing properties of each sample were evaluated. Commendable performance with maximum responsivity (1.24 × 10−1 AW−1), detectivity (1.13 × 1010 Jones), and EQE (40%) were achieved for Bi 2 S 3 :Cu:La-sample. The enhanced figures-of-merit are attributed large crystalline size, good crystallinity, lower bandgap and crack free surface. The photo sensing results may widen the field of photosensing application. [ABSTRACT FROM AUTHOR]

Abstract In this work, nanostructured methyl violet-10B (MV-10B) thin films of various thicknesses were coated on glass substrates by a low-cost spin coating method at different rpm. The structural analysis of nanostructured MV-10B thin films was carried out by X-ray diffraction and atomic force microscope. Optical measurements were carried out, and the direct band gap of MV-10B films was estimated. The study showed that the prepared MV-10B thin films act in the same manner as that of conventional direct bandgap semiconductors. From optical studies, the sample exhibited bandpass filter characteristics in IR range from 700 nm to 900 nm and in the visible range centered around 408 nm. Also, the sample absorbs or attenuates the range of wavelengths in the visible spectrum between 470 and 650 nm creating a good absorption band valley making a CUT-OFF laser filter. Optical constants such as refractive index (n) and extinction coefficient (k) were computed using Kramers–Kronig relations. The real and imaginary components of dielectric constant were calculated on the basis of polarization of light when it is impinging on semiconductors. Nonlinear index of refraction and susceptibilities were estimated by linear refractive index dispersion principles. Optical limiting studies showed that the MV-10B thin films are very good optical limiters even at low thickness. The MV-10B showed a laser attenuation behavior for He-Ne and green lasers. The obtained results suggest that the newly designed thin films are the promising candidate in different applications. Highlights • Nanostructured methyl violet-10B (MV-10B) thin films of various thicknesses were coated on glass substrates. • Kramers–Kronig relations were used to calculating the linear and nonlinear parameters of MV-10B thin films. • MV-10B thin films exhibited bandpass filter characteristics in IR range from 700 nm to 900 nm. • MV-10B thin films attenuate the He-Ne laser beam. • MV-10B can be used as CUT-OFF laser filter and laser power attenuations. [ABSTRACT FROM AUTHOR]

Abstract The present work deals with the deposition of NiO and Nitrogen (N)-doped NiO thin films by sol-gel spin coating technique. Structural, morphological, linear and non-linear optical characteristics of undoped and N-doped (1–15 wt%) NiO films were studied. From XRD measurements, it is evident that single phase nano crystalline NiO is formed for all doping concentrations. Surface morphology study shows that higher concentration of N doped NiO thin films were of high quality and EDX mapping confirmed the doping of Nitrogen in films. The Raman spectra of the studied films were analyzed over the range of 1400-200 cm−1. The optical studies confirm that as doping increases, transparency of the film decreases (except at 10% N doping) and the band gap narrows. Nonlinear parameters such as refractive index and susceptibilities also depend on N dopant concentration. Z-scan studies viz., absorption index, nonlinear refractive index were carried out on undoped and N doped NiO samples and the results were matched with theoretical calculated values. Graphical abstract Image 1 Highlights • N doped NiO films were deposited by spin coating technique. • UV-Vis-NIR study confirms high optical transparency of deposited films. • Direct energy gap was reduced from 4 eV to 3.8 eV due to n doping. • Third order nonlinear properties are enhanced due to N doping. • Values of n 2 and β are found to be of order of 10−7 and 10−2 esu, respectively. [ABSTRACT FROM AUTHOR]

In the present work, pure and dysprosium (Dy) doped SnO 2 films have been fabricated through sol-gel spin coating technique. Strong influence of Dy doping is observed on structural, morphological, vibrational, linear and nonlinear optical properties of SnO 2 films. X-ray diffraction study revealed that deposited films exhibit tetragonal crystal structure with preferentially grown along (2 0 0) plane. With increase of doping concentration in SnO 2 , the crystallite size decreases while dislocation density and lattice distortion ratio increases. The characteristics Raman peaks of doped SnO 2 thin films broaden, shifted and intensity decreases as compared to pure film which confirm the bonding between Dy and SnO 2 . Optical study shows that the prepared thin films are highly transparent and absorption increases with doping concentrations owing to increase of defects states. It is also observed that the optical band gap first increases and then lessens with rise of Dy-doping concentration which attributed to the Burstein-Moss (BM) effect. Additionally, dielectric constant and refractive index first decreasing with small doping concentration (1–3%) due to increase of carrier concentration, and then increases for higher doping (5–7%) due to increase of defect in SnO 2 lattice. The values χ 3 and β obtained by Z-scan measurement are observed in range of 0.31 × 10 −7 to 1.28 × 10 −7 and 1.27 to 5.32 × 10 −4  cm W −1 , respectively. The limiting threshold of pure and Dy doped SnO 2 nanostructured films were calculated to be in the range of 5.37–11.18 kJ/cm 2 . [ABSTRACT FROM AUTHOR]

Transparent conducting substrates (ITO) were utilized to fabricate Ni (II) Tetraphenyl Porphyrin/ITO optical systems by thermal evaporation technique. The characteristic parameters of the topological properties, such as the height profile of the surface roughness and the average height difference R a = 32.4 nm. The deviation of the Hight distribution was found to be R q = 4.8 nm. Also, there were five peaks with orientations (211), (222), (400), (440) and (622) belonging to ITO thin films. At wavelengths ≥1600 nm, the NiTPP films do not have any depicted influences on the transmittance of ITO. The Reflectance of ITO films was decreased due to the induced absorption of the NiTPP layer in visible and NIR regions. The estimated transitions between HOMO and LUMO levels were indirect for NiTPP films; the optical energy gap E o p N i T P P = 1.93 e V and the second transition was the fundamental bandgap E g N i T P P = 2.58 e V. For ITO films, the transition was direct (E g I T O = 3.66 e V). The Q-factor was investigated to declare the relationship between the stored energy and to dissipated one in the fabricated ITO/NiTPP/Al Schottky device. The uploaded applied D.C. voltage becomes more practical in shifting the value of the Q-factor towards the higher frequencies. The parallel conductance through the device reveals a mathematical relation: G p ∼ ωn, where n is an exponent dependent on the conductance through the fabricated ITO/NiTPP/Al Schottky devices. The complex electric modulus examined the interfacing properties of the fabricated Al/NiTPP/ITO systems under applied D.C. voltage from −1.5 to 1.5 V and frequency ∼42Hz to 5 MHz and elucidated that the ITO-electrode is dominant. The uploaded D.C. voltage (from −1.5 to 1.5 V) on the oscillating applied voltage signal can control the induced electric dipoles through the fabricated ITO/NiTPP/Al Schottky devices. [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]

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]

Thermal evaporation was used to grow films of the compound boron subphthalocyanine chloride (B-subPcCl) on glass substrates. X-ray diffraction was utilized to investigate the structural nature of B-SubPcCl evaporated thin films. The investigation of the film's structure exhibits the amorphous structure of the present films. Atomic force microscopy was used to examine the surface topography and grain size. B-subPcCl films are constructed of spherical nanoparticles. The optical properties of these films were investigated in the wavelength range from 250 to 2500 nm. The evaluated optical band gap energy was observed to be decreased as the film thickness increased. The dispersion parameters for B-subPcCl films were calculated using the single oscillator model and they were noticed to increase with the increase of the film thickness. The χ (3) value of the greatest film thickness (300 nm) is approximately equal to 9.6 × 10−13 esu, which is typical for optoelectronic devices. • Thermal evaporation was used to grow films of B-subPcCl on glass substrates. • The investigation of the film's structure exhibits the amorphous structure. • The evaluated optical band gap energy was observed to be decreased as the film thickness increased. • The χ (3) value of B-subPcCl films equals to 9.6 × 10−13 esu, which is typical for optoelectronic devices. [ABSTRACT FROM AUTHOR]

In this study, some barium-lead sodium borate graphene-doped glasses have been prepared. The preparation is based on the concept of weight percentage using the fast quenching methodology. The internal phases of the as-prepared solid samples have been characterized using X-ray diffraction (XRD), and Fourier Transform Infrared (FTIR). All characterization processes revealed the amorphous nature of the as-prepared samples, with an increase in the crystallinity degree as the graphene content increased. On the other hand, the optical characterization was achieved using UV–vis, which revealed a decrease in both direct and indirect optical band gaps from 3.5 to 3.32 eV and from 2.95 to 2.66 eV, respectively, as the graphene content increased. The value of Urbach's energy decreased from 0.658 to 0.641 eV, which is an anomalous behavior because it is the same as that of the optical band gaps. At the same time, the decrease in the value of Urbach's energy confirmed the results of (XRD) about the crystallinity degree. The absorption coefficient spectra have been simulated using the hydrogenic excitonic model (HEM), where some useful parameters were obtained. Such parameters indicate the indirect optical transition as the dominant absorption mechanism, which is a common feature of amorphous solids. The obtained data suggested that graphene nanopowders as a modifier can be used to improve the effectiveness of oxide glasses for UV-blockers, radiation shielding, and greenhouse applications. [ABSTRACT FROM AUTHOR]

This work has been set up to estimate how the structural, and optical properties of the copper sodium borate-based glass change when the low bandgap oxide Cu 2 O 3 is replaced by the one of the highest bandgap of Fe 2 O 3. Where the value of the optical band gap of Cu 2 O 3 (1.25–1.33 eV) is one half that of Fe 2 O 3 (2.2 eV), approximately. Using the traditional fast quenching method, three categories of solid samples have been obtained, copper-free (one sample), iron-free (one sample), and copper-iron-doped (three samples). X-ray diffraction (XRD), Transmission electron microscopes (TEM), Fourier transform infrared (FTIR), and ultraviolet-visible (UV–Vis.) spectra have been used for structural and optical characterization. XED exhibited an amorphous nature for all the prepared samples, while the FTIR showed an increase in the number of the nonbridging oxygen atoms as a result of conversion from BO 4 into BO 3. Also, FTIR showed that Fe- cations occupied the interstitial spaces as FeO 6. The Photoluminescence PL emission showed two emission peaks due to Fe2+, 3+ and Cu2+, 3+ multi-valence cations. The metallization factor, bulk density, and the optical band gaps increased when Cu 2 O 3 was replaced by Fe 2 O 3 , with an increase in the values of the molar volume and the linear refractive index. Shielding parameter Z eff referred that the Fe-Free sample is more suitable for shielding applications than the Cu-Free sample, at low energies. [ABSTRACT FROM AUTHOR]

In the present work, we systematically investigated the effect of Gd (1, 3, and 5%) doping on the structural, morphological, electrical, and optical properties of NiO thin films deposited on glass substrate using the spray pyrolysis method. X-ray diffraction study revealed that the deposited Gd:NiO(0–5%) films exhibit cubic structure with preferred orientation along (111) direction. The average crystallite size decreases from 15 nm to 12 nm with increasing Gd doping concentration. The atomic force microscope (AFM) topography study revealed that there is a decrease in grain size and variation of roughness with increasing Gd content into NiO lattice. The energy-dispersive X-ray spectroscopy (EDX)/ scanning electron microscope (SEM) mapping studies show the presence and uniform distribution of Gd in the Gd:NiO films. The average optical transparency (70%) and the optical band gap energy values decrease in Gd doped NiO films. The refractive index values are found to be in the range of 1.5–2.6. The higher values of linear and nonlinear optical parameters like χ 1 , χ 3 and n 2 are found to be 0.98 esu, 3.31 × 10−10 esu and 2.92 × 10−9 esu, respectively in Gd doped NiO films. The current study indicates that the Gd doping concentration has a strong influence on linear and non-linear optical properties of NiO films and makes them useful in several optoelectronic device applications. • Gd-doped NiO (0-5 wt.%) thin films are deposited on glass substrates using nebulizer spray pyrolysis method. • XRD and AFM support the preferred orientation of nanostructured Gd-NiO thin films. • Enhancement in linear and nonlinear optical parameters were observed. • Gd-NiO thin film is recommended for optoelectronic and nonlinear media. [ABSTRACT FROM AUTHOR]

NiO thin films were grown systematically using the nebulizer spray pyrolysis (NSP) method with different additions of Ag 1%, 2%, and 3% respectively. A photodetector was fabricated using NiO:Ag thin films. The structural, morphological, compositional, optical, and electrical properties of NiO:Ag thin films were studied as a function of Ag addition. XRD studies show a gradual reduction in the intensity and the broadening with Ag addition, which confirms the formation of nanoparticles. Ag phase has been formed after 3% of Ag addition. Compositional studies using EDS confirms the presence of all the elements. The energy band gap of films is found to be in the range 3.25–3.45 eV with an Ag addition of 1–3%. I–V characteristics and photoresponse of photodetectors were recorded under UV light illumination. The parameters of a photodetector such as external quantum efficiency, responsivity and detectivity were calculated. The observed photo responsivity increases with an increase of Ag (1%) and decreases further higher Ag concentrations.The maximum responsivity is observed for the NiO film with 1%Ag. The photoresponse of all samples confirmed the stable and reproducible characteristics such as external quantum efficiency, responsivity and detectivity.The enhanced properties observed for 1% of Ag-doped film may find applications in the fabrication of optoelectronic devices. [ABSTRACT FROM AUTHOR]

Indium-phthalocyanine-chloride (PcInCl) films have been deposited with different thicknesses onto polyacetate flexible substrate to function as a new optical limiting and laser filter application. PcInCl thin films' crystal structure has been studied by X-ray diffraction, which has amorphous forms in the different thicknesses of 50–140 nm. The optical properties of PcInCl films of various thicknesses, both linear and nonlinear, have been calculated and discussed. The refractive index and the energy gap are 2.7 and 1.36 eV, respectively. The measured nonlinear refractive and nonlinear third-order susceptibility were in the range of 10-10 esu. The high laser optical limiting of PcInCl films indicated that they could be a promising material for various laser filtering. [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]

• Transparent and conducting Indium (In) doped CdO films deposited sol-gel assisted spin coating technique. • The optical constants were calculated based on Kramers-Kroning relations. • The optical band gap value decreased with doping and is in the range of 2.73 to 2.31 eV. • The linear refractive index value increased with doping concentration, and it was in the range of 2.16 to 2.62. • The present samples are suitable for optoelectronic devices. The different ratios of Indium-doped cadmium oxide thin films were deposited on a glass substrate by a sol-gel assisted spin coating technique. The structure of the films was analyzed using XRD and depicts the amorphous nature of the doped films. All the films are highly transparent, and the value of transparency is around 80 % in the visible region. The optical constants were calculated based on Kramers-Kroning relations. The optical band gap value decreased with doping and is in the range of 2.73 to 2.31 eV. The enhancement in the linear optical properties such as refractive index, absorption index, and dielectric constant was also observed with an increase in the doping concentration. The linear refractive index value increased with doping concentration, and it was in the range of 2.16 to 2.62 indicates that the present sample is useful optical window applications. The nonlinear optical properties such as χ(1), χ (3), and n(2) are varying in the range of 0.005 to 0.468, 3.283 × 10−142 to 7.746 × 10−12 esu, and 7.986 × 10−13 to 1.119 × 10−10 esu, respectively. The enhancement in the optical properties with increasing doping concentration suggests the present films are useful for various optical device applications. The maximum dielectric constants are varying from 4.54 to 6.42, which indicates that the present samples are suitable for optoelectronic devices. Furthermore, nonlinear optical properties were analyzed and reported. [ABSTRACT FROM AUTHOR]

• Pure ZnO and doped indium have an increasing interest in the advancement of TCO. • investigated the optical spectroscopy by Kramers-Kronig (K–K) method and spectroscopy ellipsometry For ZnO and doped indium. • the increase in indium concentrations led to enhance the transmittance. The ZnO thin film doped indium has been fabricated by the sol–gel spin coater technique. The XRD confirmed the pristine ZnO and ZnO:In are polycrystalline phase. The optical constants (n, k) have been determined in terms of two analyses methods, the first was by Kramer kronig relation, and the second was by fitting a spectroscopic ellipsometric (SE) data (ψ, Δ) by means of the three-layer optical model. The calculated optical constants in terms of two analyses were comparable and affected by additional In at the expense of ZnO. The optical band gap reduced by the increase of the indium content at the expense of Zn from 3.1 to 2.7 eV. The atomic force microscope (AFM) was used to investigate the surface roughness, which was nearly approached with the surface roughness investigated by SE. [ABSTRACT FROM AUTHOR]

In this work, the high quality of CdO film with a different percentage of Ga doping prepared onto optically flat glass substrates using a sol-gel spin coating progression for enhancement of its structural characteristics for various applications. X-ray diffraction results confirm that the prepared films of CdO are amorphous due to the long-range array of deposited crystals. The images of the atomic force microscopy indicated that the surface morphology of the pure and Ga-doped CdO films has high roughness values of 60–80 nm and average particle size 85–100 nm. The optical constants were calculated using the Kramer-Kronig approach. The calculated optical transmission specifies a high transmission exceeding from 77% to 85% through the non-absorbing region depending on the doping concentrations. The results confirm that the measured optical band gap is strongly influenced by doping concentrations of Ga and decreases from 2.35 to 1.72 eV. The calculated optical dispersion and non-linear optical parameters were found to be strongly affected by doping. The terahertz cut-off frequency was set for the pure and Ga-doped CdO films indicating the applicability of the prepared films as terahertz filters. Image 1 • A high-quality thin film of Ga-doped CdO was obtained by a sol-gel spin coating. • The optical band gap is strongly influenced by doping concentrations. • The energy gap is consistent with the oscillator energy, confirming Eo/Eg ≈ 1. • The nonlinear properties support the photodiode-based devices. [ABSTRACT FROM AUTHOR]

Films of gallium-phthalocyanine-chloride (GaClPc) with various thicknesses were prepared by the vacuum thermal evaporating technique. The films' structural were studied by the X-ray diffraction pattern. It was found that GaClPc films with a thickness beyond 45 nm showed a single sharp peak at 2 θ = 26.6°. The atomic force microscopy clarified that the grain size and the roughness increased as the film's thickness increased. The absorption exhibited a high linear transmittance in the region between 350 and 650 nm. Also, the values of the band gap energies are unaffected by the film thickness. The dielectric constants of GaClPc films at different thicknesses were evaluated. The first-order (χ(1)) and the third-order (χ(3)) nonlinear susceptibility of GaClPc films were calculated. The values of (χ(3)) were increased as the film thickness was increased which may be due to the possible orientation of the molecular chains in unfavorable direction with the induced electric field as the film thickness increases. The optical limiter (OL) properties of GaClPc films have been discussed by the normalized power of two laser beams (the He–Ne laser of 638.2 nm and green diode laser of 533 nm). It was concluded that the GaClPc films can be used as a promised candidate OL material. • Nanostructure films of GaClPc were produced by a thermal evaporation technique. • The surface roughness increased as the film's thickness increased. • The values of the band gap energies are unaffected by the film thickness. • GaClPc films could be used as optical limiting devices. [ABSTRACT FROM AUTHOR]

SEM images for GO-PbI 2 nanocomposite, switching behaviour and specific detectivity of the fabricated photodetector. • For the first time, the facile microwave synthesis of GO doped PbI 2 nanoparticles are reported. • X-ray diffraction and FT-Raman studies confirm the formation of GO-PbI 2. • SEM studies confirms morphology in terms of nanoparticles decorated GO nanosheets. • The optical band gap was found to be reduced by Go doping however, still higher than bulk due to confinement effect. • Photoconductivity analysis shows GO-PbI 2 has good photodetector stability and reversibility. Herein, lead iodide (PbI 2) nanorods/graphene oxide (GO) nanocomposites have been successfully achieved at low temperature via microwave-assisted syntheses route. The X-ray diffraction (XRD) analysis confirm good crystallinity and absence of any impurity in the prepared hybrid nanostructures which further confirmed through Raman analysis. The XRD and Raman study also confirm the doping of GO in 2H polytypic PbI 2 structure. The average crystallite size of PbI 2 is calculated to be 20 nm which found to be increased to 53 nm in the case of GO-PbI 2 for high intensity peak. Scanning electron microscope (SEM) images reveal that the GO sheets are decorated with PbI 2 nanoparticles and nanorods. The absorption spectra of PbI 2 was found to broaden whereas energy bandgap of GO-PbI 2 decreases to 2.83 eV in compare to 3.24 eV for PbI 2. The effect of graphene oxide doping on photodetector performance of PbI 2 was elucidated by measuring the I-V characteristics under 532 nm laser light illumination. The pure PbI 2 exhibits a stable and reversible photodetector performance with responsivity of 0.060 AW−1, detectivity of 6.38 × 1010 Jones, EQE of ∼14 % and response time of 224 ms. For GO-doped PbI 2 , these parameters were found to be improved to 0.182 AW−1, 1.79 × 1011 Jones, ∼42 %, and 128 ms, respectively. [ABSTRACT FROM AUTHOR]