scholarly journals Effect of Postdeposition Annealing on the Structural, Electrical, and Optical Properties of DC Magnetron SputteredTa2O5Films

2007 ◽  
Vol 2007 ◽  
pp. 1-5 ◽  
Author(s):  
S. V. Jagadeesh Chandra ◽  
P. Sreedhara Reddy ◽  
G. Mohan Rao ◽  
S. Uthanna
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Optical Properties ◽  
Annealing Temperature ◽  
Optical Band Gap ◽  
Optical Transmittance ◽  
Electrical Characteristics ◽  
Electrical And Optical Properties ◽  
Tantalum Target ◽  
Deposited Films

Thin films of tantalum oxide were formed on quartz and silicon (111) substrates kept at room temperature (303 K) by reactive sputtering of tantalum target in the presence of mixture of oxygen and argon gases. The as-deposited films were annealed in air for an hour in the temperature range 673–873 K. The films were characterized by studying structural, dielectric, electrical, and optical properties. The as-deposited films were amorphous in nature. As the annealing temperature increased to 673 K, the films were transformed into polycrystalline. Electrical characteristics of as-deposited and annealedTa2O5thin films were compared. The thermal annealing reduced the leakage current density and increased the dielectric constant. The optical transmittance of the films increased with the increase of annealing temperature. The as-deposited films showed the optical band gap of 4.38 eV. It increased to 4.44 eV with the increase of annealing temperature to 873 K. The as-deposited films showed the low value (1.89) of refractive index and it increased to 2.15 when annealed at 873 K. The increase of refractive index with annealing temperature was due to the increase in the packing density and crystallinity of the films.

Effect of Argon Gas Pressure on Optical Properties of Zinc Oxide Thin Films Deposited by RF Magnetron Sputtering Technique

2014 ◽  
Vol 904 ◽  
pp. 205-208
Author(s):  
J.H. Gu ◽  
Z.Y. Zhong ◽  
S.B. Chen ◽  
C.Y. Yang ◽  
J. Hou
Keyword(s):  
Thin Films ◽  
Zinc Oxide ◽  
Refractive Index ◽  
Optical Properties ◽  
Magnetron Sputtering ◽  
Optical Band Gap ◽  
Rf Magnetron Sputtering ◽  
Gas Pressure ◽  
Argon Gas ◽  
Deposited Films

Zinc oxide (ZnO) thin films were deposited by radio frequency (RF) magnetron sputtering technique on glass substrates in pure argon gas. The optical transmission stectra of the films were measured by ultraviolet-visible spectrophotometer. The effects of argon gas pressure on optical properties of the deposited films were investigated. The optical band-gap of the films was evaluated in terms of the Taucs law. The results show that the argon gas pressure has slightly affected the optical band-gap of the deposited films. Furthermore, the refractive index and extinction coefficient of the films were determined by means of the optical characterization methods. Meanwhile, the dispersion behavior of the refractive index was studied by the single-oscillator model of Wemple and DiDomenico, and the physical parameters of the average oscillator strength, average oscillator wavelength, oscillator energy, the refractive index dispersion parameter and the dispersion energy were obtained.

ON THE STRUCTURE, ELECTRICAL AND OPTICAL PROPERTIES OF TiO2 SPUTTERED THIN FILMS

2006 ◽  
Vol 13 (01) ◽  
pp. 87-92 ◽  
Author(s):  
A. ASHOUR
Keyword(s):  
Thin Films ◽  
Optical Constants ◽  
Optical Band Gap ◽  
Optical Transmittance ◽  
X Ray Diffraction ◽  
Electrical And Optical Properties ◽  
X Ray ◽  
Lattice Constants ◽  
Glass Substrates ◽  
Deposited Films

Titanium oxide thin films were prepared by sputtering technique onto glass substrates at room temperature (RT). The structure of the films was confirmed using X-ray diffraction (XRD) and revealed the stoichiometry with an O and Ti ratio of 2. The deposited films at RT were found to be amorphous and the films annealed at 300 and 400°C for 2 h were crystalline with orthorhombic structure. The lattice constants and grain size of the film are calculated. The electrical resistivity was found to depend on the film thickness and decreased with increasing the film thicknesses. The optical constants of the films such as the refractive index, extinction coefficient, and absorption coefficient were also determined using the optical transmittance measurements, and the results were discussed. The optical band gap varies from 3.2 to 3.5 eV as a function of oxygen/argon ratios.

scholarly journals Annealing Effect on Some Optical Properties of Cr2O3 Thin Films Prepared by Spray Pyrolysis Technique

2011 ◽  
Vol 8 (2) ◽  
pp. 561-565
Author(s):  
Baghdad Science Journal
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Refractive Index ◽  
Optical Properties ◽  
Absorption Coefficient ◽  
Spray Pyrolysis ◽  
Annealing Temperature ◽  
Spray Pyrolysis Technique ◽  
Annealing Effect ◽  
Before And After

Cr2O3 thin films have been prepared by spray pyrolysis on a glass substrate. Absorbance and transmittance spectra were recorded in the wavelength range (300-900) nm before and after annealing. The effects of annealing temperature on absorption coefficient, refractive index, extinction coefficient, real and imaginary parts of dielectric constant and optical conductivity were expected. It was found that all these parameters increase as the annealing temperature increased to 550°C.

Effects of Nitrogen Doping on Optical Properties of Tungsten Oxide Thin Films

2012 ◽  
Vol 616-618 ◽  
pp. 1773-1777
Author(s):  
Xi Lian Sun ◽  
Hong Tao Cao
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Optical Properties ◽  
Band Gap ◽  
Tungsten Oxide ◽  
Nitrogen Doping ◽  
Optical Band Gap ◽  
Band Gap Energy ◽  
Gap Energy ◽  
Tungsten Oxide Thin Films

In depositing nitrogen doped tungsten oxide thin films by using reactive dc pulsed magnetron sputtering process, nitrous oxide gas (N2O) was employed instead of nitrogen (N2) as the nitrogen dopant source. The nitrogen doping effect on the structural and optical properties of WO3 thin films was investigated by X-ray diffraction, transmission electron microscopy and UV-Vis spectroscopy. The thickness, refractive index and optical band gap energy of these films have been determined by analyzing the SE spectra using parameterized dispersion model. Morphological images reveal that the films are characterized by a hybrid structure comprising nanoparticles embeded in amorphous matrix and open channels between the agglomerated nanoparticles. Increasing nitrogen doping concentration is found to decrease the optical band gap energy and the refractive index. The reduced band gaps are associated with the N 2p orbital in the N-doped tungsten oxide films.

Dependence of electrical and optical properties of sol–gel prepared undoped cadmium oxide thin films on annealing temperature

2005 ◽  
Vol 493 (1-2) ◽  
pp. 83-87 ◽  
Author(s):  
J. Santos-Cruz ◽  
G. Torres-Delgado ◽  
R. Castanedo-Perez ◽  
S. Jiménez-Sandoval ◽  
O. Jiménez-Sandoval ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Cadmium Oxide ◽  
Oxide Thin Films ◽  
Electrical And Optical Properties

scholarly journals Effect of gamma irradiation on structural, morphological and optical properties of p-quaterphenyl thin films

2018 ◽  
Vol 14 (2) ◽  
pp. 5624-5637
Author(s):  
A.A. Attia ◽  
M.M. Saadeldin ◽  
K. Sawaby
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Optical Properties ◽  
Surface Morphology ◽  
Absorption Coefficient ◽  
Gamma Irradiation ◽  
Band Gap ◽  
Optical Band Gap ◽  
Thermal Evaporation Method ◽  
Single Oscillator Model

Para-quaterphenyl thin films were deposited onto glass and quartz substrates by thermal evaporation method. p-quaterphenyl thin films wereexposed to gamma radiation of Cobat-60 radioactive source at room temperature with a dose of 50 kGy to study the effect of ?-irradiation onthe structure and the surface morphology as well as the optical properties of the prepared films. The crystalline structure and the surface morphology of the as-deposited and ?-irradiated films were examined using the X-ray diffraction and the field emission scanning electron microscope. The optical constants (n & k) of the as-deposited and ?-irradiated films were obtained using the transmittance and reflectance measurements, in the wavelength range starting from 250 up to 2500 nm. The analysis of the absorption coefficient data revealed an allowed direct transition with optical band gap of 2.2 eV for the as-deposited films, which decreased to 2.06 eV after exposing film to gamma irradiation. It was observed that the Urbach energy values change inversely with the values of the optical band gap. The dispersion of the refractive index was interpreted using the single oscillator model. The nonlinear absorption coefficient spectra for the as-deposited and ?-irradiated p-quaterphenyl thin films were obtained using the linear refractive index.

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