scholarly journals The Physical and Optical Studies of Crystalline Silica Derived from the Green Synthesis of Coconut Husk Ash

2020 ◽  
Vol 10 (6) ◽  
pp. 2128 ◽  
Author(s):  
Muhammad Fahmi Anuar ◽  
Yap Wing Fen ◽  
Mohd Hafiz Mohd Zaid ◽  
Khamirul Amin Matori ◽  
Rahayu Emilia Mohamed Khaidir
Keyword(s):  
Green Synthesis ◽  
Acid Treatment ◽  
Energy Gap ◽  
Negative Effects ◽  
Optical Energy Gap ◽  
X Ray ◽  
Coconut Husk ◽  
Optical Applications ◽  
The Fourier Transform ◽  
Coconut Shells

The green synthesis of silica has been extensively explored over the last few decades, as silica compounds found in commercial products can cause negative effects on human health. This calls for alternative ways to produce silica that are safer, cheaper and more environmentally friendly. Some of the agricultural wastes proven to contain silica include rice husk, sugarcane bagasse, coconut shells and coconut husk. This paper describes the synthesis of silica from coconut husk waste, and its physical and optical properties for potential utilization in optical applications. Coconut husk was subjected to fire at 500–700 °C so as to form coconut husk ash (CHA), and was then treated with sulfuric acid to extract silica from the ash. Most of the weight degradation subsequently occurred at temperatures from 221 to 360 °C. X-ray fluorescence (XRF) analysis proved that 91.76% of the silica was obtained, while major peaks on the X-ray diffraction (XRD) spectrum were observed after the acid treatment. Chemical bonds such as Si-O-Si, CH2, -OH and Si-OH were found in the spectrum of the Fourier transform infrared spectroscopy (FTIR). Furthermore, the particles displayed rod-like shapes and irregular sizes, but the particle with sizes ranging from 200–750 nm decreased after the acid treatment. The relationship between the absorption coefficient and photon energy was obtained by finding the optical energy gap, which was found to be 4.3 eV. These data points provide critical information when used in optical applications. The overall studies show that synthesized silica has great potential for use in optical field applications.

scholarly journals Plasmonic nanostructures of SnO2:Sb thin film under gamma radiation response

2020 ◽  
Vol 38 (1) ◽  
pp. 62-72
Author(s):  
A. F. Maged ◽  
M. Amin ◽  
H. Osman ◽  
L.A. M. Nada
Keyword(s):  
Gamma Radiation ◽  
Thermal Annealing ◽  
Energy Gap ◽  
Negative Refractive Index ◽  
Spray Pyrolysis Technique ◽  
Radiation Response ◽  
Plasmonic Nanostructures ◽  
Optical Energy Gap ◽  
Glass Substrates ◽  
Optical Applications

AbstractThis paper is a part of a natural dye solar cell project. Conductive transparent oxide (CTO) films have been deposited onto preheated glass substrates using a spray pyrolysis technique. The optical, electrical, structural properties as well as thermal annealing and gamma radiation response were studied. The average optical energy gap of doped films for direct allowed and direct forbidden transitions were found to be 3.92 and 3.68 eV, respectively. The plasmon frequency and plasmon energy after doping were found to be 3.48 × 1014 s −1 and 0.23 eV. The negative absorbance of the doped film was observed in UV-Vis range after applying both thermal annealing and γ-dose irradiation with 22 kGy. The negative refractive index of the doped film in UV range (220 – 300 nm) is promising for optical applications. The electron mobility μe reached a maximum of 27.4 cm2 V−1 s−1 for Sb concentration of 10 %. The corresponding resistivity ρ, and sheet resistance Rs reached their minimum values of 1.1 × 10−3 Ω cm and 35 Ω sq−1, respectively. The dopant concentration has been increased from 4.13 × 1019 to 2.1 × 1020cm−3. The doped film was found to exhibit three diffraction peaks associated with (2 2 2), (2 0 0), and (2 1 1) reflection planes, of which the peak of (2 2 2) of Sb2O3 and the peak of (2 0 0) were very close.

scholarly journals Laser induced plasma of cadmium oxide: structural, morphological and optical properties

2021 ◽  
Vol 2114 (1) ◽  
pp. 012012
Author(s):  
Tamara S. Hussein ◽  
Ala F. Ahmed
Keyword(s):  
Optical Properties ◽  
Energy Gap ◽  
Cadmium Oxide ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
Optical Energy Gap ◽  
X Ray ◽  
Laser Induced Plasma ◽  
Atomic Force ◽  
Doping Ratio

Abstract In this study, the effect of grafting with Iron (Fe) ratios (0.1, 0.3 and 0.5) on the structural and optical properties of cadmium oxide films (CdO) was studied, as these films were prepared on glass bases using the method of pulse laser deposition (PLD). The crystallization nature of the prepared films was examined by X-ray diffraction technique (XRD), which showed that the synthesis of the prepared films is polycrystalline, and Atomic Force Microscope (AFM) images also showed that the increased vaccination with Iron led to an increase in the crustal size ratio and a decrease in surface roughness, The absorption coefficient was calculated and the optical energy gap for the prepared thin films. It was found the absorption decreases and the energy gap decreases with the increase of doping ratio.

scholarly journals Optical and structural study for DLC thin films prepared by plasma jet

2019 ◽  
Vol 17 (40) ◽  
pp. 50-58
Author(s):  
S. J. Kadhem
Keyword(s):  
Thin Films ◽  
High Voltage ◽  
Plasma Torch ◽  
Energy Gap ◽  
Plasma Jet ◽  
Optical Energy Gap ◽  
X Ray ◽  
Xrd Diffraction ◽  
Fourier Transformation Infrared Spectroscopy ◽  
Uv Visible

Diamond-like carbon (DLC) homogeneous thin films were deposited from cyclohexane (Ccyclohexane (Ccyclohexane (Ccyclohexane (C cyclohexane (Ccyclohexane (Ccyclohexane (C cyclohexane (Ccyclohexane (C 6H12 ) liquid by using a plasma jet system which operates with alternating high voltage 7.5 which operates with alternating high voltage 7.5which operates with alternating high voltage 7.5which operates with alternating high voltage 7.5 which operates with alternating high voltage 7.5which operates with alternating high voltage 7.5which operates with alternating high voltage 7.5 which operates with alternating high voltage 7.5which operates with alternating high voltage 7.5 which operates with alternating high voltage 7.5which operates with alternating high voltage 7.5 which operates with alternating high voltage 7.5which operates with alternating high voltage 7.5 which operates with alternating high voltage 7.5 which operates with alternating high voltage 7.5which operates with alternating high voltage 7.5which operates with alternating high voltage 7.5which operates with alternating high voltage 7.5 which operates with alternating high voltage 7.5which operates with alternating high voltage 7.5 which operates with alternating high voltage 7.5 which operates with alternating high voltage 7.5which operates with alternating high voltage 7.5which operates with alternating high voltage 7.5which operates with alternating high voltage 7.5which operates with alternating high voltage 7.5 kv and kv and kv and kv and frequency 28 frequency 28frequency 28 frequency 28frequency 28frequency 28frequency 28frequency 28 kHz. kHz. The optical and structural properties and chemical bonding of these films were investigated. In this work, the effect of changing the distance between the substrate and the plasma torch (2, 2.5 and 3 cm) was studied. The flow rate of argon gas which used to generate the plasma was fixed (0.5 L/min). These films were characterized by UV–Visible spectrophotometer, X-ray diffractometer (XRD) and scanning electron microscopy (SEM) and Fourier transformation infrared spectroscopy (FTIR). The maximum absorption (λmax) appears around 312, 298.3 and 293.2 nm at the three distance between plasma torch and the substrate 2.5, 2 and 3 cm, respectively. The values of the optical energy gap are 3.47, 3.65 and 3.76 eV at a different distance (2, 2.5 and 3cm), respectively. In XRD diffraction pattern, The occurrence of diamond peaks and graphite peaks in the x-ray spectrum for these films Indicates that there is an occurrence of local ordered sp3 and sp2 for carbon domains and graphite respectively.

Enhanced Absorption Edge of Anchusa-Italica-Doped Pentacene towards Optoelectronic Applications

2020 ◽  
Vol 1002 ◽  
pp. 251-263
Author(s):  
Tahseen A. Alaridhee ◽  
Fatima H. Malk ◽  
Abdullah A. Hussein ◽  
Dawod S. Abid
Keyword(s):  
Fourier Transform ◽  
Energy Gap ◽  
Band Gap Energy ◽  
Optical Energy Gap ◽  
Transmittance Spectra ◽  
Enhanced Absorption ◽  
Ft Ir ◽  
Optoelectronic Applications ◽  
The Fourier Transform ◽  
Doped Polymer

The dye-doped polymer is commonly used in the field of optoelectronics, given its effectiveness in optimising the device’s performance. This study is devoted to the synthesis and characterisation of Anchusa-Italica-doped Pentacene thin-film. Scanning electronic microscopy structural analysis, Fourier transform spectroscopy, and UV-visible transmittance spectra with a range of 300-900 nm were also carried out. The fundamental optical properties such as the absorption coefficient, optical energy gap, absorption and refractive indices were calculated based on the methods already used in the literature as Tauc’s relationship. The morphology of the samples indicated that dye structure was affected in the doped pentacene. The Fourier transform infrared technique (FT-IR) resulting spectrum of the doped samples also showed a significant absorption peak corresponding to C-H as an index of impurities. The calculated band-gap energy of the impurity sample was reduced and was the lowest compared to both the pure dye and polymer samples. The optical absorption and transmittance spectra revealed that it was positioned in the desirable ranges for optoelectronic applications. An anomaly in the absorption index was also observed through excitation of the resonance mode with transparent indication. This effect was deduced from the calculation of the refractive index. The results presented in this paper significantly contribute to the developments in the field of optoelectronic devices based on dye/polymer organic materials.

scholarly journals Optical and Structural investigations of LiNbO3 thin films by PLD

2020 ◽  
pp. 17-23
Keyword(s):  
Thin Film ◽  
Substrate Temperature ◽  
Energy Gap ◽  
Ultra Violet ◽  
Raw Material ◽  
Laser Deposition ◽  
X Ray Diffraction ◽  
Optical Energy Gap ◽  
Structural Investigations ◽  
X Ray

Lithium niobate (LiNbO3) nanostructure thin film was prepared and deposited on the substrates made of quartz by utilizing pulse laser deposition (PLD) technique. The effect of substrate temperature changing on the optical and structural properties of LiNbO3 films was investigated and studied. The chemical mixture was prepared by mixing the raw material (Li2CO3, Nb2O5) with Ethanol liquid without any further purification, at the stirrer time 3hrs without heating, then the formed material was overexposed to annealing process at 1000°C for 4hrs. LiNbO3 nanostructure thin film was characterized and analyzed by utilizing the Ultra-Violet visible (UV-vis) and X-Ray Diffraction (XRD). The UV-vis results showed that the increase in the substrate temperature to 300°C leads to decrease in the values of transmission (T%), absorption (A) and optical energy gap (Eg) and increase in the values of reflection (R%) and refractive index (n). While, the XRD results explained that the LiNbO3 structure became more pure and crystalline with increase the substrate temperature, because the intensity of the phase 2θ at the value of 34.8°, 40.06° and 48.48° correspond to (110), (113) and (024) planes disappeared at the substrate temperature 300°C. So, all presented results give a good indication to use LiNbO3 nanostructure thin film prepared at the substrate temperature 300°C for manufacturing the optical waveguide to give the best results.

scholarly journals High-responsivity hybrid α-Ag2S/Si photodetector prepared by pulsed laser ablation in liquid

2020 ◽  
Vol 11 ◽  
pp. 1596-1607
Author(s):  
Raid A Ismail ◽  
Hanan A Rawdhan ◽  
Duha S Ahmed
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Laser Ablation ◽  
Energy Gap ◽  
Longitudinal Optical Phonon ◽  
Ambient Conditions ◽  
Optical Energy Gap ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Scanning Electron

We report the synthesis of α-Ag2S nanoparticles (NPs) by one-step laser ablation of a silver target in aqueous solution of thiourea (Tu, CH4N2S) mixed with cationic cetyltrimethylammonium bromide (CTAB) as surfactant. The effect of the CTAB surfactant on the structural, morphological, optical, and elemental composition of Ag2S NPs was evaluated using X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and UV–vis spectroscopy. The optical absorption decreased and the optical energy gap of α-Ag2S increased from 1.5 to 2 eV after the CTAB surfactant was added to the Tu solution. XRD studies revealed that the synthesized Ag2S NPs were polycrystalline with a monoclinic structure and that crystallinity of the nanoparticles was improved after adding CTAB. Raman studies revealed the presence of peaks related to Ag–S bonds (Ag modes) and the longitudinal optical phonon 2LO mode. Scanning electron microscopy investigations confirmed the production of monodisperse Ag2S NPs when using the CTAB surfactant. The optoelectronic properties of α-Ag2S/p-Si photodetector, such as current–voltage characteristics and responsivity in the dark and under illumination, were also improved after using the CTAB surfactant. The responsivity of the photodetector increases from 0.64 to 1.85 A/W at 510 nm after adding CTAB. The energy band diagram of the α-Ag2S/p-Si photodetector under illumination was constructed. The fabricated photodetectors exhibited reasonable stability after three weeks of storage under ambient conditions with a responsivity of 70% of the initial value.

scholarly journals Influence of Cr2O3 Nanoparticles on the Structural, Optical, Thermal and Electrical Properties of PEO/CMC Nanocomposites

2021 ◽  
Author(s):  
Laila Gaabour
Keyword(s):  
Energy Gap ◽  
Average Particle Size ◽  
Nanocomposite Films ◽  
Average Particle ◽  
Cole Plot ◽  
Optical Energy Gap ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Cr2o3 Nanoparticles ◽  
A Charge

Abstract In the present paper, different concentrations of chromium oxide (Cr2O3) nanoparticles were incorporated within PEO/CMC polymer blend to produce nanocomposite films using the casting method. The X-ray diffraction was performed on PEO/CMC-Cr2O3 nanocomposites. The main X-ray peaks of Cr2O3 were observed and defined as cubic structure and orthorhombic shape with an average particle size of the Cr2O3 ~ 50-80 nm. The decrease of some IR bands after the addition of Cr2O3 nanoparticles was found attributed to the interactions between PEO/CMC and Cr2O3. Effect of Cr2O3 nanoparticles on optical properties such as absorbance and optical energy gap (Eg) were characterized using UV-Vis spectroscopy. The Eg was reduced after the addition of Cr2O3 nanoparticles. The AC conductivity (sac), dielectric constant (ε′), dielectric loss (ε′′) and the dielectric modulus (M′ and M′′) were calculated at frequency range 0.1 Hz-7 GHz. The increases of direct conductivity (σdc) imply that the free charge density or of the charge mobility that results. The estimated values of both ε′ and ε′′ were decreased with increases of frequency. The addition of Cr2O3 nanoparticles causes the formation of a charge-transfer complex. The Cole-Cole plot between (M′ and M′′) shows a semi-circular shape confirm discuses according to a non‐Debye method.

scholarly journals Enhancement of vanadium oxide doped Eu+3 for gas sensor application

2019 ◽  
Vol 15 (33) ◽  
pp. 17-27
Author(s):  
Hassan M. Odhaib
Keyword(s):  
Thin Films ◽  
Response Time ◽  
Vanadium Oxide ◽  
Energy Gap ◽  
Average Frequency ◽  
Europium Oxide ◽  
X Ray Diffraction ◽  
Optical Energy Gap ◽  
X Ray ◽  
Vis Spectroscopy

Thin films of vanadium oxide nanoparticles doped with different concentrations of europium oxide (2, 4, 6, and 8) wt % are deposited on glass and Si substrates with orientation (111) utilizing by pulsed laser deposition technique using Nd:YAG laser that has a wavelength of 1064 nm, average frequency of 6 Hz and pulse duration of 10 ns. The films were annealed in air at 300 °C for two hours, then the structural, morphological and optical properties are characterized using x-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM) and UV-Vis spectroscopy respectively. The X-ray diffraction results of V2O5:Eu2O3 exhibit that the film has apolycrystalline monoclinic V2O5 and triclinic V4O7 phases. The FESEM image shows a homogeneous pattern and confirms the formation of uniform nanostructures on the glass substrate. The type of the particle found nanoparticles with different doping concentrations of Eu2O3. The optical energy gap increases with the increase of doping concentration and it varies from 2.67 eV to 2.71 eV. The prepared thin films are used to fabricate sensor against nitrogen dioxide gas. The dependence of sensitivity and response time on doping ratio and operation temperature of gas sensors has been studied, the maximum sensitivity was about 100%, the response time is equal to 24s and recovery time 16s for V2O5 doped 2% Eu2O3 at 50 °C.

scholarly journals Structural and optical properties for PVA- PEG-MnCl2 composites

2019 ◽  
Vol 15 (32) ◽  
pp. 99-113
Author(s):  
Mahdi Hasan Suhail
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Polymer Blend ◽  
Extinction Coefficient ◽  
Energy Gap ◽  
Dielectric Constants ◽  
Structural And Optical Properties ◽  
Optical Energy Gap ◽  
X Ray ◽  
Amorphous Structures

Polymer films of PEG and PVA and their blend with differentconcentrations of MnCl2 (0, 2, 4, 6 and 10 %.wt) were study usingcasting technique. The X-ray spectra of pure PEG, PVA andPVA:PEG films and with addition of 2% concentrations from(MnCl2) show amorphous structures. The results for FTIR show theinteraction between the filler and polymer blend results indecreasing crystallinity with rich amorphous phase. Thisamorphous nature confirms the complexation between the filler andthe polymer blend. The optical properties of (PVA:PEG/MnCl2)contain the recording of absorbance (A) and explain that theabsorption coefficient (α), refractive index (n), extinction coefficient(ko) and the dielectric constants (real and imaginary part) increasewith increasing the concentration of Composite (PVA:PEG/MnCl2).The optical energy gap for electrons transitions both are direct andindirect allowed.

Preparation of Cu2ZnSnS4 Thin Film by So-Gel Spin-Coated Deposition

2009 ◽  
Vol 79-82 ◽  
pp. 835-838 ◽  
Author(s):  
Min Yen Yeh ◽  
Chin Cheng Lee ◽  
Dong Sing Wuu
Keyword(s):  
Solar Cells ◽  
Energy Gap ◽  
Sol Gel ◽  
Solar Irradiation ◽  
Optical Absorption Coefficient ◽  
X Ray Diffraction ◽  
Optical Energy Gap ◽  
Texture Surface ◽  
X Ray ◽  
High Absorption

In this work Cu2ZnSnS4 (CZTS) suitable for the absorption layer in solar cells was successfully prepared by sol-gel spin-coated deposition. CZTS precursors were prepared by using solutions of copper (II) chloride, zinc (II) chloride, tin (IV) chloride, and thiourea. The CZTS with texture surface structures, resulting from 3 times of stacks through the cycles of spin-coated and synthesized (at 320 °C) processes, is found to be merged well together, and the thickness of the CZTS reaches ~ 3 μm. The kesterite crystallinity of the CZTS designated from the x-ray diffraction of (112), (200), (312), and (322) planes of CZTS were obtained. The optical-energy gap of the CZTS is about 1.5 eV. The average optical-absorption coefficient of the CZTS is ~ 2.4 x 104 cm-1, and the high absorption band of the CZTS covers most of the solar irradiation spectrum. This makes the CZTS the most potential material for solar cells. The chemical composition Cu:Zn:Sn:S = 30:14:16:40 of the CZTS is obtained at a synthesized temperature of 320 °C.

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