scholarly journals Sol-Gel Derived Cds Nanocrystalline Thin Films: Optical and Photoconduction Properties

2018 ◽  
Vol 36 (2) ◽  
pp. 235-241 ◽  
Author(s):  
Ziaul Raza Khan ◽  
Anver Aziz ◽  
Mohd. Shahid Khan ◽  
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Sol Gel ◽  
Hexagonal Wurtzite Structure ◽  
Solution Temperature ◽  
Nanocrystalline Phase ◽  
Glass Substrates ◽  
Coating Method ◽  
Potential Applications ◽  
Nanocrystalline Thin Films

Abstract High-quality CdS nanocrystalline thin films were grown by sol-gel spin coating method at different solution temperatures on glass substrates. As-deposited films exhibited nanocrystalline phase with hexagonal wurtzite structure and showed good adhesion and smooth surface morphology. It was clearly observed that the crystallinity of the thin films improved with the increase in solution temperature. Crystallites sizes of the films also increased and were found to be in the range of 10 mm to 17 nm. The influence of the growth mechanism on the band and sub-band gap absorption of the films was investigated using UV-Vis and photothermal deflection spectroscopy (PDS). The band gap values were calculated in the range of 2.52 eV to 2.75 eV. The band gap decreased up to 9 % with the increase in solution temperature from 45 °C to 75 °C. Absorption coefficients estimated by PDS signal showed the significant absorption in low photon energy region of 1.5 eV to 2.0 eV. The dark and illuminated I-V characteristics revealed that the films were highly photosensitive. The results demonstrated the potential applications of sol-gel grown CdS nanocrystalline thin films as photoconductors and optical switches.

Influence of Annealing Temperature on Nanocrystalline ZnO Thin Films Prepared by Sol-Gel Dip Coating Method

2013 ◽  
Vol 678 ◽  
pp. 97-102
Author(s):  
K. Sivakumar ◽  
V. Senthil Kumar ◽  
Mariyappan Thambidurai ◽  
Thottipalayam Subramaniyan Senthil
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Band Gap ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Dip Coating ◽  
Zno Thin Films ◽  
Coating Method ◽  
Dip Coating Method ◽  
Nanocrystalline Thin Films

ZnO nanocrystalline thin films have been prepared on glass substrates by sol-gel dip coating method. The ZnO thin films have been coated at room temperature for the pH value of 10 and annealed at 300°, 400° and 500°C respectively. The X- ray diffraction pattern shows that ZnO nanocrystalline thin films are of hexagonal structure and the grain size is found to be in the range of 25-45 nm. Scanning electron microscope images show that the surface morphology improves with increase of annealing temperature. The TEM analysis reveals the formation of ZnO nanocrystalline with an average grain size of 44 nm. The compositional analysis results show that Zn and O are present in the sample. The optical studies shows that the films are highly transparent and exhibit a direct band gap. The band gap has been found to lie in the range of 3.07 to 3.32 nm depending on the annealed temperature suggesting the formation of ZnO nanocrystalline thin films.

Preparation and characterization of V2O5 doped SiO2-TiO2 thin films

2012 ◽  
Vol 2 (1) ◽  
Author(s):  
Marek Nocuń ◽  
Sławomir Kwaśny
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Dip Coating ◽  
Band Gap Energy ◽  
Tio2 Thin Films ◽  
Glass Substrates ◽  
Gel Technique

AbstractIn our investigation, V doped SiO2/TiO2 thin films were prepared on glass substrates by dip coating sol-gel technique. Chemical composition of the samples was studied by X-ray photoelectron spectroscopy (XPS). Transmittance of the samples was characterized using UV-VIS spectrophotometry. Subsequently band-gap energy (Eg) was estimated for these films. Powders obtained from sols were characterized by FTIR spectroscopy. It was found that vanadium decreases optical band gap of SSiO2/TiO2 films.

scholarly journals Opto-Electronic Properties of Epoxy/Silicone Blend Based Thin Films

2021 ◽  
Author(s):  
Younes Ziat ◽  
Hamza Belkhanchi ◽  
Maryama Hammi ◽  
Charaf Laghlimi ◽  
A Moutcine
Keyword(s):  
Thin Films ◽  
Indium Tin Oxide ◽  
Optical Transition ◽  
Sol Gel ◽  
Glass Substrates ◽  
Nanostructured Thin Films ◽  
Ito Glass ◽  
Potential Applications ◽  
Optical Applications ◽  
Nitrogen Doped Carbon

Abstract Recently, the rise of two dimensional amorphous nanostructured thin films have ignited a big interest because of their intriguingly isotropic structural and physical properties leading to potential applications in the nano-optoelectronics. However, according to literature, most of optoelectronic properties are investigated on chalcogenides related heterostructures. This has motivated the present work aiming to provide a new platform for the fabrication, examination of the properties and the applications of 2D nanostructured thin films based on epoxy/silicone blend. Thin films of Epoxy/Silicone loaded with nitrogen doped carbon nanotubes (N-CNTs) were prepared by sol-gel method and deposited on Indium Tin Oxide (ITO) glass substrates at room temperature. Further examination of optical properties aimed the investigation of optical pseudo-gap and Urbach energy and enabled the determination of processed films thickness based on Manifacier and Swanepol method. The results indicated that the unloaded thin films have a direct optical transition with a value of 3.61 eV followed by noticeable shift towards narrowing gaps depending on the loading rate. Urbach's energy is 0.19 eV for the unloaded thin films, and varies from 0.43 to 1.33 eV for the loaded thin films with increasing the rate of N-CNTs. It is inversely variable with the optical pseudo-gap. Finally, Epoxy/Silicone loaded with N-CNTs nanocomposites films can be developed as active layers with specific optical characteristics, giving the possibility to be used in electro-optical applications.

SPECTROSCOPIC ELLIPSOMETRY INVESTIGATION ON OPTICAL PROPERTIES OF Fe:SNO2 THIN FILMS: EFFECTS OF IRON CONCENTRATION

2020 ◽  
pp. 2050044
Author(s):  
SAHAR MORADI ◽  
HASSAN SEDGHI
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Spectroscopic Ellipsometry ◽  
Sol Gel ◽  
Iron Concentration ◽  
Dielectric Constants ◽  
Bandgap Energy ◽  
Dispersion Parameters ◽  
Glass Substrates ◽  
Coating Method

Nanostructured Fe:SnO2 thin films were deposited on glass substrates through sol–gel spin coating method. Films were synthesized with different iron quantities including 0%, 4%, 8% and 12% (wt.%). The effects of Fe concentration on optical properties of films were investigated by spectroscopic ellipsometry (SE) technique. SE measured ([Formula: see text]) parameters for films in the wavelength range between 300[Formula: see text]nm to 800[Formula: see text]nm. Optical properties including the refractive index, extinction coefficient, transmittance, dielectric constants and optical conductivity were determined by fitting the SE measured ([Formula: see text]) parameters and data obtained from the optical model-based analysis. Results showed that the transmittance values increase by increment of Fe concentration from 0% to 12%. The bandgap energy ([Formula: see text] of prepared thin films was also calculated. [Formula: see text] values were between 3.44 and 3.58[Formula: see text]eV. Dispersion parameters including the high frequency dielectric constant ([Formula: see text] and the ratio of free carrier concentration to effective mass (N/m[Formula: see text] were then obtained for the prepared films.

Influence of Ni Doping on Structural, Morphological and Optical Properties of Sol-Gel ZnO Thin Films

2016 ◽  
Vol 675-676 ◽  
pp. 241-244 ◽  
Author(s):  
Tanattha Rattana ◽  
Sumetha Suwanboon ◽  
Chittra Kedkaew
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Surface Morphology ◽  
Doping Concentration ◽  
Sol Gel ◽  
Hexagonal Wurtzite Structure ◽  
Dip Coating ◽  
Zno Thin Films ◽  
Ni Doping ◽  
Coating Method

Ni-doped ZnO thin films were prepared on glass slide substrates by a sol-gel dip coating method with different Ni doping concentrations (0-33 mol%). The effect of Ni doping concentration on structural, surface morphology and optical properties of the thin films was characterized by XRD, FESEM and UV-Vis spectrophotometer. The XRD results indicated that pure ZnO thin film exhibited a hexagonal wurtzite structure. Ni (OH)2 phase were observed at a high Ni doping concentration. The FESEM images showed that the surface morphology and surface roughness were sensitive to the Ni doping concentration. The optical transmission measurements were observed that the transmittance decreased with increasing the Ni doping concentration.

Electrical Properties of Indium-Doped Zinc Oxide Nanostructures Doped at Different Dopant Concentrations

2015 ◽  
Vol 1109 ◽  
pp. 593-597
Author(s):  
M.F. Nasir ◽  
Mohd Hannas ◽  
Mohamad Hafiz Mamat ◽  
Mohamad Rusop
Keyword(s):  
Thin Films ◽  
Zinc Oxide ◽  
Optical Properties ◽  
Electrical Properties ◽  
Near Infrared ◽  
Sol Gel ◽  
Zinc Oxide Nanostructures ◽  
Glass Substrates ◽  
In Doping ◽  
Coating Method

This project has been focused on the electrical and optical properties on the effect of Indium doped zinc oxide (ZnO) thin films at different dopant concentrations. These thin films were doped with different In dopant concentrations at 1 at%, 1.5 at%, 2 at%, 3 at%, 4 at% and 5 at% was selected as the parameter to optimize the thin films quality while the annealing temperature is fixed 500 oC. In doped ZnO solutions were deposited onto the glass substrates using sol-gel spin coating method. This project was involved with three phases, which are thin films preparation, deposition and characterization. The thin films were characterized using Current Voltage (I-V) measurement and UV-Vis-NIR spectrophotometer for electrical properties and optical properties. The electrical properties show that the resistivity is the lowest at 4 at% In doping concentration which is 8.27× 103Ωcm-1The absorption coefficient spectrum obtained from UV-Vis-NIR spectrophotometer measurement shows all films exhibit very low absorption in the visible (400-800nm) and near infrared (NIR) (>800nm) range but exhibit high absorption in the UV range.

STRUCTURAL AND OPTICAL INVESTIGATIONS ON NANOCRYSTALLINE TiO2 THIN FILMS PREPARED BY SOL–GEL SPIN COATING TECHNIQUE

2010 ◽  
Vol 09 (04) ◽  
pp. 355-358 ◽  
Author(s):  
T. S. SENTHIL ◽  
M. THAMBIDURAI ◽  
N. MUTHUKUMARASAMY ◽  
R. BALASUNDARAPRABHU
Keyword(s):  
Thin Films ◽  
Spin Coating ◽  
Anatase Phase ◽  
Sol Gel ◽  
Diffraction Method ◽  
Tio2 Thin Films ◽  
Nanocrystalline Tio2 ◽  
Glass Substrates ◽  
Coating Method ◽  
Different Temperatures

TiO2 thin films have been deposited onto well cleaned glass substrates by sol–gel spin coating method. The prepared TiO2 films have been annealed at different temperatures (350°C, 450°C and 550°C). The structural properties of the films have been studied using X-ray diffraction method and High Resolution Transmission Electron Microscope (HRTEM). The as-deposited films have been found to be amorphous in nature. The crystalline quality has been observed to improve with annealing temperature. The annealed TiO2 films have been found to exhibit anatase phase. The optical properties have been studied using transmittance spectrum.

Effect of Crystallite Size on the Optical and Structural Properties of Gadolinium-Doped Zinc Oxide

2016 ◽  
Vol 1133 ◽  
pp. 414-418 ◽  
Author(s):  
Nurul Fadzilah Ab Rasid ◽  
Siti Nooraya Mohd Tawil ◽  
Norhidayah Che Ani ◽  
Mohd Zainizan Sahdan
Keyword(s):  
Thin Films ◽  
Crystallite Size ◽  
Diluted Magnetic Semiconductor ◽  
Sol Gel ◽  
Magnetic Semiconductor ◽  
Band Gap Energy ◽  
Optical Investigation ◽  
Glass Substrates ◽  
Coating Method ◽  
Diluted Magnetic

Rare earth Gd-doped ZnO thin films were prepared by a simple sol-gel spin coating method in order to search for a new functional diluted magnetic semiconductor for potential application in spintronics. The thin films were deposited onto glass substrates with zinc acetate dehydrate, monoethanolamine and 2-methoxyethanol as a starting material, stabilizer and solvent, respectively. The dopant percentage was increased up to 8%. Optical investigation showed that the crystallinity of the thin films was changing due to the increase of the Gd concentrations and optical band gap energy (Eg) value was estimated to be around 3.12 ~ 3.28 eV using Tauc's model. The crystallite size determined from XRD spectra and the results was found that the value is in the range of 14.42 ~ 21.98 nm.

scholarly journals Characteristics and optical properties of Fe3+ doped SiO2/TiO2 thin films prepared by the sol-gel dip-coating method

2013 ◽  
Vol 16 (1) ◽  
pp. 92-100
Author(s):  
Chien Mau Dang ◽  
Dam Duy Le ◽  
Tam Thi Thanh Nguyen ◽  
Dung Thi My Dang
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Sol Gel ◽  
Dip Coating ◽  
X Ray Diffraction ◽  
Tio2 Thin Films ◽  
Water Contact ◽  
Glass Substrates ◽  
Coating Method ◽  
Dip Coating Method

In this study, we have successfully synthesized Fe3+ doped SiO2/TiO2 thin films on glass substrates using the sol-gel dip-coating method. After synthesizing, the samples were annealed at 5000C in the air for 1 hour. The characteristics and optical properties of Fe3+ doped SiO2/TiO2 films were then investigated by X-ray diffraction (XRD), ultraviolet-visible spectroscopy (UV-vis) and Fourier transform infrared spectroscopy (FT-IR). An antifogging ability of the glass substrates coated with the fabricated film is investigated and explained by a water contact angle under visible-light. The analyzed results also show that the crystalline phase of TiO2 thin films comprised only the anatase TiO2, but the crystalline size decreased from 8.8 to 5.9 nm. We also observed that the absorption edge of Fe3+- doped SiO2/TiO2 thin films shifted towards longer wavelengths (i.e. red shifted) from 371.7nm to 409.2 nm when the Fe3+-doped concentration increased from 0 to 1 % mol.

Spectral Features of Zn1-xMgxO Thin Films Synthesized by the Sol-Gel Route

2013 ◽  
Vol 669 ◽  
pp. 296-301 ◽  
Author(s):  
Feng Lin Xian ◽  
Xiang Yin Li
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
Phase Segregation ◽  
Hexagonal Wurtzite Structure ◽  
Blue Shift ◽  
Content Increase ◽  
Ultraviolet Emission ◽  
Glass Substrates ◽  
Structure Morphology ◽  
Probe Microscope

Zn1-xMgxO (x=0, 0.05, 0.1, 0.2 and 0.3, respectively) thin films have been synthesized by sol-gel method on glass substrates. The structure, morphology and optical properties of the samples have been studied by X-ray diffractonmeter (XRD), scanning probe microscope, UV-visible spectrophotometer, fluorescence spectrophotometer and spectroscopic ellipsometer, respectively. The XRD result shows that all the films have hexagonal wurtzite structure; no phase segregation is observed. The surfaces of Zn1-xMgxO thin films are smooth and the root mean square (RMS) roughness of the samples is only several nanometers. The transmittance spectra reveal that all samples have high transmittance above 90%, with Mg doping content increase, the optical band gap increases from 3.27eV to 3.77eV. The photoluminescence spectra show that all samples have two emission peaks in ultraviolet and violet region, a blue shift of ultraviolet emission is observed. The refractive indexes of all samples decrease with the increase of wavelength ranging from 350nm to 900nm. The refractive index changes apparently by varying Mg content, which has potential application in research of optical materials and the design of optical devices.

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