Electrical and photoconductivity properties of p-Si/P3HT/Al and p-Si/P3HT:MEH-PPV/Al organic devices: Comparison study

The electrical and photoresponse properties of the p-Si/P3HT/Al and p-Si/P3HT:MEH-PPV/Al organic devices have been investigated by current-voltage and capacitance-voltage characteristics. The diode parameters such as ideality factor, barrier height, rectification ratio, Richardson constant, and series resistance were determined from current-voltage characteristics at different temperatures. The diodes indicate a non-ideal current-voltage behavior due to the ideality factor being higher than unity due to the effect of series resistance and the presence of an interfacial layer. The interface state density D it values of the P3HT and P3HT:MEH-PPV diodes vary from 1.829 × 10 10 to 3.825 × 10 11 eV -1 cm -2 and from 4.561 × 10 11 to 3.233 × 10 12 eV -1 cm -2, respectively. The photoconductivity properties of the diodes under various illuminations have been investigated. The photoconductivity parameters of the P3HT:MEH-PPV diode are higher than that of photoconductivity parameters of the P3HT diode. © 2012 Elsevier B.V. All rights reserved

Synthesizing and exploring the structural and optical properties of PVA/PVP/PEG polymeric sheet upon doping with nano nickel oxide (NiO) for CUT-OFF filters

Developing novel composite polymeric materials with noteworthy characteristics is vital for crucial research and optical applications in numerous sectors. Using the solution casting method, the blend of the hydrophilic (polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), and polyethylene glycol (PEG)), polymeric composites was evaluated as host carriers for important metal oxide particles of NiO at different concentrations (0.05,0.27,0.55,2.7,5.5,11.04 wt%). The semi-crystalline structural behavior of the produced polymeric sheets was determined by X-ray diffraction (XRD), the surface morphology and the mean grain size of the NiO nanoparticles were investigated through the scanning electron microscopy (SEM), as well as the presence of the O–H group on the PVA/PVP/PEG polymers was identified by the remarkable Fourier transform-infrared (FT-IR) analysis. Using a UV–Vis spectrophotometer, the remarkable impacts of various NiO dopant ratios on the optical properties, transmittance, absorbance, absorption coefficient, and extinction coefficient, of the considered NiO: PVA/PVP/PEG composite sheets were examined. Pure PVA/PVP/PEG polymeric composites have transmittance spectra that are 91 % in the visible range, then drop to 0 % as raising the concentrations of NiO NPs. Additionally, the π-π transition of blend segments is revealed by the studied NiO-doped PVA/PVP/PEGsheets' absorption spectra, which peak at 350 nm. The direct/indirect bandgaps for the pure polymer are (5.40 and 4.98 eV), and they are reduced to (4.81 and 2.84 eV) with the weight of NiO increased, respectively. Based on the optical energy bandgaps (Eg) of the NiO: PVA/PVP/PEG thin composite sheets, seven different models were used to precisely quantify the nonlinear optical characteristics and linear refractive index (n). With the highest concentrations of NiO, the high-frequency dielectric values increased, and the static dielectric constant decreased. The prepared nanocomposites reduced the intensity of three different types of lasers at a wavelength (635 nm, 532 nm, and 450 nm) and the intensity of optical lampe at power 1036 W/ m2. The outstanding findings strongly suggest that the proposed NiO: PVA/PVP/PEG thin composite sheets be designed for various optoelectronic, optical filters, and laser medical applications

Design of Rose Bengal/FTO optical thin film system as a novel nonlinear media for infrared blocking windows

Rose Bengal (RB) is a new organic semiconductor with the highly stable layer, was deposited on highly cleaned conductive glass substrate known as (FTO glass) with different thickness in the range from 80 to 292 nm. XRD showed an entirely amorphous structure of the studied film thicknesses. The observed peaks are the indexed peaks for FTO layer. Spectrophotometric data as transmittance, reflectance, and absorbance were used for the analysis the optical constant of RB/FTO optical thin film system. Refractive index was calculated using Fresnel’s equation with the aid of reflectance and absorption index. The dielectric constant, dielectric loss and dissipation factor were discussed and analyzed according to the applied optical theories. Nonlinear parameters such as third order nonlinear optical susceptibility and the nonlinear refractive index were calculated based on the linear refractive index of the applications of this material in nonlinear media. The results showed that Rose Bengal is a proving material for wide scale optoelectronic applications such as infrared blocking windows. Keywords: Rose Bengal, Dielectric parameters, Linear/nonlinear optics, Dye/FTO, IR blocking window

Designing of PVA/Rose Bengal long-pass optical window applications

Poly(vinyl alcohol) (PVA)/Rose Bengal (RB) composite films were prepared by casting technique form aqueous solutions doped with different dye concentrations. The effect of dye concentration on the structure, spectroscopic and optical properties was characterized by X-ray diffraction, optical absorption and fluorescence spectroscopy. The optical limiting properties of PVA/RB films were measured using He-Ne laser beam at 632.8 nm wavelength and showed the best optical limiting behavior at high dye concentrations. The results were interpreted on the basis of hydrogen bonding between hydroxyl groups in PVA and the carbonyl group of face-to face stacked H-aggregates of RB molecules which was evident by all the characterization techniques. Furthermore, PVA/10 wt% RB film showed excellent optical cut-off properties in the spectral range (600–1400 nm) with a high transmission value (Σ 84%) which is a promising result for the long-pass optical filters and protective window applications. Keywords: PVA, Rose Bengal, H-aggregates, Optical limiting, Long-pass filter

Microwave synthesis of Zn:Mn:PbI2 micro-size nanosheets and their characterizations

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

Optical properties of CdS thin films

The properties of CdS thin films were investigated by applying atomic force microscopy (AFM), Raman and far-infrared spectroscopy. CdS thin films were prepared by using the thermal evaporation technique under base pressure 2 × 10−5 torr. The quality of these films was investigated by AFM spectroscopy. We applied Raman scattering and far-infrared spectroscopy to investigate the optical properties of CdS thin films, and reveal the existence of Surface Optical Phonon (SOP) mode at 297 cm−1. Effective permittivity of mixture was modeled by Maxwell–Garnet approximation. In the analysis of the far-infrared reflection spectra, a numerical model for calculating the reflectivity coefficient for a system which includes films and substrate was applied

Novel waves structures for two nonlinear partial differential equations arising in the nonlinear optics via Sardar-subequation method

In this paper, our aim is to construct the novel wave structures for two non-linear evolution equations which are rising in non-linear optics, mathematical biological models, fluid dynamics, waves theory, mechanics, quantum mechanics, and many more. We employed an efficient analytical technique namely, the Sardar-subequation method to build the wave solutions for the modified Benjamin-Bona-Mahony equation and the Coupled Klein–Gordon equations. We have built the numerous type of soliton wave structures of modified Benjamin-Bona-Mahony equation and the Coupled Klein–Gordon equations via the Sardar-subequation method. Acquired results reveal the dynamics behavior of waves structures including the bright, singular, dark, and periodic singular solitons solutions. To illustrate the behavior of these solutions some selected solutions are sketched in two-, and three-dimensional graphs. On the basis of these results, our technique is suitable, up-to-date, and powerful. The obtained solutions are very efficacious and influential in non-linear optics, mathematical biology, mechanics, fluid mechanics, plasma physics, and many more. This study will assist to predict some new hypothesis and theories in the field of mathematical physics