Single Phase CuO Thin Films Prepared by Thermal Oxidation in Air with Water Vapor

2015 ◽  
Vol 1109 ◽  
pp. 544-548 ◽  
Author(s):  
Jian Bo Liang ◽  
Xu Yang Li ◽  
Naoki Kishi ◽  
Tetsuo Soga

Single phase CuO films have been successfully synthesized by thermal oxidation of cupper foil in air with water vapor. The structural and optical properties of CuO films were investigated. It is observed that the grain size increases with increasing the oxidation temperature. The optical band gap of CuO film is determined by the transmittance and reflectance spectra.

Crystals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 132 ◽  
Author(s):  
Theopolina Amakali ◽  
Likius. S. Daniel ◽  
Veikko Uahengo ◽  
Nelson Y. Dzade ◽  
Nora H. de Leeuw

Zinc oxide (ZnO) is a versatile and inexpensive semiconductor with a wide direct band gap that has applicability in several scientific and technological fields. In this work, we report the synthesis of ZnO thin films via two simple and low-cost synthesis routes, i.e., the molecular precursor method (MPM) and the sol–gel method, which were deposited successfully on microscope glass substrates. The films were characterized for their structural and optical properties. X-ray diffraction (XRD) characterization showed that the ZnO films were highly c-axis (0 0 2) oriented, which is of interest for piezoelectric applications. The surface roughness derived from atomic force microscopy (AFM) analysis indicates that films prepared via MPM were relatively rough with an average roughness (Ra) of 2.73 nm compared to those prepared via the sol–gel method (Ra = 1.55 nm). Thin films prepared via MPM were more transparent than those prepared via the sol–gel method. The optical band gap of ZnO thin films obtained via the sol–gel method was 3.25 eV, which falls within the range found by other authors. However, there was a broadening of the optical band gap (3.75 eV) in thin films derived from MPM.


2018 ◽  
Vol 12 (3) ◽  
pp. 199-208
Author(s):  
Maja Popovic ◽  
Mirjana Novakovic ◽  
Kun Zhang ◽  
Miodrag Mitric ◽  
Natasa Bibic ◽  
...  

Polycrystalline CrN thin films were irradiated with Xe ions. The irradiation-induced modifications on structural and optical properties of the films were investigated. The CrN films were deposited on Si(100) wafers with the thickness of 280 nm, by using DC reactive sputtering. After deposition, the films were implanted at room temperature with 400 keV Xe ions with the fluences of 5-20?1015 ions/cm2. The films were then annealed at 700 ?C in vacuum for 2 h. The combination of Rutherford backscattering spectrometry (RBS), X-ray diffraction (XRD) and transmission electron microscopy (TEM) was used for structural analyses, while changes in optical properties were monitored by spectroscopic ellipsometry. We also measured the electrical resistivity of the samples using a four point probe method. RBS analysis reveals that the concentration of Xe in the layers increases with ion fluence reaching the value of around 1.5 at.% for the highest ion dose, at a depth of 73 nm. XRD patterns show that the irradiation results in the decrease of the lattice constant in the range of 0.4160-0.4124 nm. Irradiation also results in the splitting of 200 line indicating the tetragonal distortion of CrN lattice. TEM studies demonstrate that after irradiation the columnar microstructure is partially destroyed within _90 nm, introducing a large amount of damage in the CrN layers. Spectroscopic ellipsometry analysis shows that the optical band gap of CrN progressively reduces from 3.47 eV to 2.51 eV with the rise in ion fluence up to 20?1015 ions/cm2. Four point probe measurements of the films indicated that as the Xe ion fluence increases, the electrical resistivity rises from 770 to 1607 ?Wcm. After post-implantation annealing crystalline grains become larger and lattice distortion disappears, which influences optical band gap values and electrical resistivity of CrN.


2012 ◽  
Vol 229-231 ◽  
pp. 10-13
Author(s):  
Liang Yan Chen ◽  
Chao Fang

ZnSe thin films were obtained through chemical bath deposition method. Structural and optical properties of as deposited and annealed samples were investigated by X-ray Diffraction and spectrophotometer. The as deposited thin films were in nanocrystalline, with lots of strain and a blue shift of optical band gap. After annealing, the crystal grain gained, the strain eased and optical band gap enlarged. And it suggested that annealing can ease the quantum effect of chemical bath deposited ZnSe thin films.


2013 ◽  
Vol 770 ◽  
pp. 225-228
Author(s):  
L. Uttayan ◽  
K. Aiempanakit ◽  
M. Horprathum ◽  
P. Eiamchai ◽  
V. Pattantsetakul ◽  
...  

Titanium dioxide (TiO2) films were prepared by thermal oxidation from Ti films. The Ti films were deposited on glass and silicon (100) wafer substrate by dc magnetron sputtering and subsequent with thermal oxidation process. The crystal structure and morphology of TiO2 films were estimated by using X-ray diffractometry (XRD) and field-emission scanning electron microscopy (FE-SEM), respectively. The optical property of TiO2 films was determined by UV-Visible spectrophotometer. The influences of annealing temperature between 200 to 500°C in air for 1 hour on the structure and optical properties of TiO2 films were investigated. The increasing of annealing temperature was directly affected the phase transition from Ti to TiO2. The optical and structural properties of TiO2 films are the best exhibited with increasing the annealing temperature at 500 °C.


2019 ◽  
Vol 27 (03) ◽  
pp. 1950124 ◽  
Author(s):  
MOHAMMED YARUB HANI ◽  
ADDNAN H. AL-AARAJIY ◽  
AHMED M. ABDUL-LETTIF

Nickel(II) phthalocyanine-tetrasulfonic acid tetrasodium salt (NiTsPc) thin films were deposited on glass substrates at different substrate temperatures ([Formula: see text]) by chemical spray pyrolysis (CSP) technique. The substrate temperature varied from 110∘C to 310∘C in 50∘C steps. The substrate surface temperature is the main parameter that determines the film morphology and properties of the thin films. The structural properties of the deposited NiTsPc thin films were investigated by X-ray diffraction (XRD) and from the obtained results, it was shown that depositing thin films using 210∘C as [Formula: see text] results in higher crystallinity. Atomic force microscope (AFM) was employed to obtain the surface topography and to calculate the roughness and grain size. The smoothest thin film surface was obtained when using at 160∘C, while the highest roughness was obtained at 310∘C. The optical properties were investigated by ultraviolet visible (UV-Vis) spectrophotometer and fluorescence spectrophotometer. From the absorption spectra recorded in the wavelength range 190–1100[Formula: see text]nm, two absorption bands were observed, which are known as Soret and Q-band. By observing the absorption spectrum, it can be concluded that the deposited thin films at 110∘C–310∘C have direct energy gap. From Tauc plot relation, the energy gap ([Formula: see text]) was calculated. The values of the energy gap were between 3.05 and 3.14[Formula: see text]eV. It was observed that different [Formula: see text] highly affects the structural and optical properties of the deposited thin films. The crystallinity, grain size, roughness and the optical properties were strongly affected by the different substrate temperatures.


2005 ◽  
Vol 905 ◽  
Author(s):  
B. Yang ◽  
Y. M. Lu ◽  
C. Neumann ◽  
A. Polity ◽  
C. Z. Wang ◽  
...  

AbstractDelafossite-type CuAlO2 thin films have been deposited by radio frequency (RF) reactive sputtering on sapphire using a CuAlO2 ceramic target. A study of structural and optical properties was performed on films of varying deposition parameters such as substrate temperature and oxygen partial pressure and also post annealing. The crystalline phase in the films was identified to be the delafossite structure by x-ray diffraction. The optical properties, such as the wavelength dependence of the transmittance and the band gap, were determined. The average transmittance is 80% in the wavelength range of 400-1500 nm and the band gap is 3.81 eV.


2012 ◽  
Vol 616-618 ◽  
pp. 1773-1777
Author(s):  
Xi Lian Sun ◽  
Hong Tao Cao

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.


2018 ◽  
Vol 14 (2) ◽  
pp. 5624-5637
Author(s):  
A.A. Attia ◽  
M.M. Saadeldin ◽  
K. Sawaby

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.


Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 934 ◽  
Author(s):  
Shamil R. Saitov ◽  
Dmitriy V. Amasev ◽  
Alexey R. Tameev ◽  
Vladimir V. Malov ◽  
Marine G. Tedoradze ◽  
...  

Electrical, photoelectrical, and optical properties of thin films of a new heat-resistant polyphenylquinoline synthesized using facile methods were investigated. An analysis of the obtained temperature dependences of the dark conductivity and photoconductivity indicates the hopping mechanism of conductivity over localized states arranging at the energy distance of 0.8 eV from the Fermi level located inside the band gap of the investigated material. The optical band gap of the studied material was estimated from an analysis of the spectral dependences of the photoconductivity and absorption coefficient before (1.8–1.9 eV) and after (2.0–2.2 eV) annealing at temperatures exceeding 100 °C. The Gaussian character of the distribution of the localized states of density inside the band gap near the edges of the bands was established. A mechanism of changes in the optical band gap of the investigating polymer under its annealing is proposed.


2010 ◽  
Vol 17 (05n06) ◽  
pp. 497-503 ◽  
Author(s):  
F. K. YAM ◽  
S. S. TNEH ◽  
Y.-Q. CHAI ◽  
W. S. LAU ◽  
Z. HASSAN ◽  
...  

In this work, a series of polycrystalline ZnO samples have been synthesized from Zn thin films deposited on Si (100) substrates by using thermal oxidation technique. The ZnO thin film samples grown by this technique were then characterized by a variety of structural and optical characterization tools. The results revealed that the use of novel annealing process i.e. the application of temperature gradient in the thermal treatment could enhance the structural and optical quality of the ZnO thin films significantly as compared to the normal annealing process, i.e. a fixed temperature under different durations. Apart from the improvement of structural and optical properties of ZnO thin films, another striking feature of this novel annealing process was the promotion of the growth of ZnO nanostructures.


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