Structural and optical properties of thermal decomposition assisted Gd 2 O 3 :Ho 3+ /Yb 3+ upconversion phosphor annealed at different temperatures

2016 ◽  
Vol 167 ◽  
pp. 134-141 ◽  
Author(s):  
A. Kumar ◽  
S.P. Tiwari ◽  
K. Kumar ◽  
V.K. Rai
Keyword(s):  
Thermal Decomposition ◽  
Optical Properties ◽  
Structural And Optical Properties ◽  
Different Temperatures

Structural and Optical Properties of Nanocrystalline ZnO Powder by a Direct Thermal Decomposition Route Using Zinc Acetate Dihydrate

2014 ◽  
Vol 979 ◽  
pp. 151-154
Author(s):  
Weeranuch Kaewwiset ◽  
Tarinee Srisuphang ◽  
Sasiprapa Keawsomrong ◽  
Sutthipoj Sutthana ◽  
Supphadate Sujinnapram
Keyword(s):  
Thermal Decomposition ◽  
Optical Properties ◽  
Crystallization Temperature ◽  
Zinc Acetate ◽  
Zinc Acetate Dihydrate ◽  
Acetate Dihydrate ◽  
Structural And Optical Properties ◽  
Different Temperatures ◽  
Zno Powders ◽  
Zno Powder

The nanocrystalline ZnO powders were synthesized by a direct thermal decomposition using zinc acetate dihydrate as starting materials. The precursor was characterized by TG-DTA to determine the thermal decomposition and crystallization temperature which was found to be at 300 °C. The precursors were calcined at different temperatures of 400, 500, and 600 °C for 4 h. The structure of the prepared samples was studied by XRD, confirming the formation of wurtzite structure. The synthesized powders exhibited the UV absorption below 400 nm (3.10 eV) with a well defined absorption peak at around 285 nm (4.35 eV). The estimated direct bandgaps were obtained to be 3.19, 3.16, and 3.14 eV for the ZnO samples thermally decomposed at 400, 500, and 600°C, respectively.

Structural and Optical Properties of α-Ga2O3 Films Deposited on Sapphire (10‾10) and (01‾12) Substrate by MOCVD

2013 ◽  
Vol 746 ◽  
pp. 369-373 ◽  
Author(s):  
Yu Lv ◽  
Wei Mi ◽  
Cai Na Luan ◽  
Jin Ma
Keyword(s):  
Optical Properties ◽  
Optical Band Gap ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Structural And Optical Properties ◽  
Visible Wavelength Range ◽  
Average Transmittance ◽  
Different Temperatures ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition

Ga2O3thin films were grown on sapphire m-cut () and r-cut () orientations substrates at different temperatures by metal-organic chemical vapor deposition. Structural and optical properties of the Ga2O3films were investigated including the influence by annealing for the obtained films. The Ga2O3films on sapphire () and () substrate areα-Ga2O3. The crystallization of the films decreases after annealed at 900 °C. The average transmittance of the samples in the visible wavelength range was over 86% and the optical band gapEgwas about 4.755.15 eV. TheEgof the samples increases after annealing at 900 °C.

Structural and Optical Properties of ZnO Film Precursors for Multilayered Transparent Solar Cell Electrodes

2015 ◽  
Vol 1132 ◽  
pp. 217-223
Author(s):  
E.R. Rwenyagila ◽  
B. Agyei-Tuffour ◽  
M.G.Z. Kana ◽  
O. Akin-Ojo ◽  
W.O. Soboyejo
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Rf Magnetron Sputtering ◽  
Zno Thin Films ◽  
X Ray Diffraction ◽  
Zno Film ◽  
Structural And Optical Properties ◽  
X Ray ◽  
Deposition Power ◽  
Different Temperatures

This work examines the modification of the structural and optical properties of ZnO thin films by control of deposition and post-treatment parameters. ZnO thin films were deposited by RF magnetron sputtering from a ceramic target locally made at SHESTCO in Abuja, Nigeria. X-ray diffraction measurements characterized the different films prior to thermal annealing as extremely amorphous with average UV-VIS transmittance spectra between 80 and 90%. Annealing at different temperatures and time spans influenced the formation of Wurtzite (002) oriented ZnO crystallites. Contrary to the crystallinity of the films, which was strongly influenced by the deposition power, the optical transmission of the films was only slightly influenced by the deposition power and it was less sensitive to the crystallinity of ZnO thin films.

scholarly journals Effect of Annealing Temperature on the Structural and Optical Properties of TiO2 Thin Film Prepared by Sol-gel Method

2016 ◽  
Vol 8 (3) ◽  
pp. 267-272 ◽  
Author(s):  
F. U. Khan ◽  
M. Zubair ◽  
M. Z. Ansar ◽  
M. K. Alamgir ◽  
S. Nadeem
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Surface Morphology ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Rutile Phase ◽  
Structural And Optical Properties ◽  
Tio2 Thin Films ◽  
Different Temperatures ◽  
Xrd Patterns

The effect of annealing temperatures on the surface morphology and optical properties of titanium dioxide (TiO2) thin films deposited by spin coating on Silicon substrate was studied. The TiO2 thin films deposited onto silicon substrates were annealed at different temperatures. The structural and optical properties were studied using scanning electron microscopy (SEM), X-ray diffraction technique (XRD) and optical ellipsometer. The results indicated that the structural properties of the TiO2 thin films were changed with the increase in annealing temperature. The SEM investigation showed that as annealing temperature was increased, the grain and pores size were increased. The XRD patterns of the studied samples showed that rutile phase were found in a sample annealed at high temperature. The ellipsometry investigation shows that the refractive index increased while energy band gap decreased with the annealing temperature. The results showed that surface porosity, optical properties and surface morphology of TiO2 could be affected by changing the annealing temperature.   

STRUCTURAL AND OPTICAL PROPERTIES OF SOL-GEL DERIVED BARIUM TITANATE THIN FILM

2007 ◽  
Vol 21 (11) ◽  
pp. 1837-1849 ◽  
Author(s):  
H. BASANTAKUMAR SHARMA
Keyword(s):  
Optical Properties ◽  
Barium Titanate ◽  
Sol Gel ◽  
Amorphous Film ◽  
Structural And Optical Properties ◽  
Single Oscillator Model ◽  
Dispersion Data ◽  
Crystalline Films ◽  
Different Temperatures ◽  
Single Oscillator

Ferroelectric barium titanate ( BaTiO 3) films have been prepared from barium acetate and titanium (IV) isopropoxide precursors by the sol-gel technique. The structural and optical properties of films annealed at different temperatures have been investigated. The as-fired films were found to be amorphous and crystallized to the tetragonal phase after annealing at 700°C for one hour in air. The lattice constants "a" and "c" were found to be 3.996 Å and 4.040 Å respectively. The X-ray density of the crystalline film was about 6.00 g · cm -3. The amorphous film showed very high transparency (~95%), which decreased slightly after crystallization (~90%). The band gap and the refractive index of the amorphous and crystalline films were estimated. The influences of porosity on the optical properties of films have also been investigated. The optical dispersion data are also analyzed in the light of the single oscillator model, and are discussed.

scholarly journals Photoluminescence Emission and Structure Study in ZnO:Ag nanorods

2015 ◽  
Vol 5 (01) ◽  
pp. 55
Author(s):  
Erick Velázquez Lozada ◽  
G M Camacho-González ◽  
J M Quino-Cerdan
Keyword(s):  
Optical Properties ◽  
Ultrasonic Spray Pyrolysis ◽  
Structure Study ◽  
Zno Films ◽  
Photoluminescence Spectra ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy ◽  
Structural And Optical Properties ◽  
Ultrasonic Spray ◽  
Different Temperatures

<p>Scanning electronic microscopy (SEM) andX ray diffraction (XRD) have been applied to the study of structural and optical properties of ZnOnanocrystals prepared by the ultrasonic spray pyrolysis (USP) at different temperatures. The variation of temperatures and times at the growth of ZnO films permits modifying the ZnO phase from the amorphous to crystalline, to change the size of ZnOnanocrystals (NCs), as well as to vary their photoluminescence spectra. </p>

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