scholarly journals Synthesis and characterization of Cu doped chromium oxide (Cr2O3) thin films

2019 ◽  
Vol 38 (2019) ◽  
pp. 806-812 ◽  
Author(s):  
Ahlam Zekaik ◽  
Hadj Benhebal ◽  
Bedhiaf Benrabah
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
Visible Region ◽  
Dip Coating ◽  
Nyquist Plot ◽  
Degree Of Crystallinity ◽  
Cu Doping ◽  
Parallel Circuit ◽  
High Degree

AbstractCu-doped Cr2O3 thin films were deposited onto glass substrate by the sol–gel dip-coating (SGDC) process using dopant values of 0, 3, 6, 9 and 12%. The Chromium (III) Nitrate Nonahydrate [Cr(NO3)3·9H2O] was used as a Cr source, whilst for the dopant, the corresponding nitrate (Cu(NO3)2) was used. The crystal structure, as well as the optical and electrical properties were examined. XRD data showed that the films with a high degree of crystallinity were rhombohedral Cr2O3 phase. The crystallite size reduces with increase in Cu doping proportion. The AFM results indicate a decrease in the surface roughness of the doped Cr2O3: Cu thin films. The UV-Vis spectra of the Cu doped-Cr2O3 films showed high transparency in the visible region. The optical band gap of Cr2O3 thin films decreases with increasing in Cu doping rate. The Nyquist plot shows that the equivalent circuit of Cu doped-Cr2O3 films is a parallel circuit RpCp. As the concentration of Cu increases, Resistance RP regresses while capacitance Cp increases.

Photocatalytic Degradation of Methylene Blue by NiO Thin Films under Solar Light Irradiation

2019 ◽  
Vol 56 ◽  
pp. 152-157 ◽  
Author(s):  
Abdelouahab Noua ◽  
Hichem Farh ◽  
Rebai Guemini ◽  
Oussama Zaoui ◽  
Tarek Diab Ounis ◽  
...  
Keyword(s):  
Thin Films ◽  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Sol Gel ◽  
Visible Region ◽  
Optical Transmittance ◽  
Dip Coating ◽  
Light Irradiation ◽  
Solar Light ◽  
Solar Light Irradiation

Nickel oxide (NiO) thin films were successfully deposited by sol-gel dip-coating method on glass substrates. The structural, morphological and optical properties in addition to the photocatalytic activity of the prepared films were investigated. The results show that the films have a polycrystalline NiO cubic structure with dense NiO grains and average optical transmittance in the visible region. The photocatalytic properties of the films were studied through the degradation of methylene blue and 89% of degradation was achieved for 4.5h of solar light irradiation exposure which indicates the capability of NiO photocatalytic activity.

Characterization of SrBi2Nb2O9 Thin Films Prepared by Sol Gel Technique

1996 ◽  
Vol 459 ◽  
Author(s):  
E. Ching-Prado ◽  
W. Pérez ◽  
A. Reynés-Figueroa ◽  
R. S. Katiyar ◽  
D. Ravichandran ◽  
...  
Keyword(s):  
Thin Films ◽  
Raman Band ◽  
Sol Gel ◽  
Orthorhombic Symmetry ◽  
X Ray Diffraction ◽  
Ft Ir ◽  
Gel Technique ◽  
High Degree ◽  
First Time

ABSTRACTThin films of SrBi2Nb2O9 (SBN) with thicknesses of 0.1, 0.2, and 0.4 μ were grown by Sol-gel technique on silicon, and annealed at 650°C. The SBN films were investigated by Raman scatering for the first time. Raman spectra in some of the samples present bands around 60, 167, 196, 222, 302, 451, 560, 771, 837, and 863 cm−1, which correspond to the SBN formation. The study indicates that the films are inhomogeneous, and only in samples with thicknesses 0.4 μ the SBN material was found in some places. The prominent Raman band around 870 cm−1, which is the A1g mode of the orthorhombic symmetry, is assigned to the symmetric stretching of the NbO6 octahedrals. The frequency of this band is found to shift in different places in the same sample, as well as from sample to sample. The frequency shifts and the width of the Raman bands are discussed in term of ions in non-equilibrium positions. FT-IR spectra reveal a sharp peak at 1260 cm−1, and two broad bands around 995 and 772 cm−1. The bandwidths of the latter two bands are believed to be associated with the presence of a high degree of defects in the films. The experimental results of the SBN films are compared with those obtained in SBT (T=Ta) films. X-ray diffraction and SEM techniques are also used for the structural characterization.

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.

Sol-gel synthesis and characterization of Ag nanoparticles in ZrO2 thin films

2009 ◽  
Vol 24 (8) ◽  
pp. 2541-2546 ◽  
Author(s):  
Eisuke Yokoyama ◽  
Hironobu Sakata ◽  
Moriaki Wakaki
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
Composite Films ◽  
Dip Coating ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Silver Surface ◽  
Molar Ratios ◽  
Sol Gel Synthesis

ZrO2 thin films containing silver nanoparticles were prepared using the sol-gel method with Ag to Zr molar ratios [Ag]/[Zr] = 0.11, 0.25, 0.43, 0.67, 1.00, 1.50, and 2.33. After dip coating on glass substrate, coated films were annealed at 200 and 300 °C in air. X-ray diffraction peaks corresponding to crystalline Ag were observed, but a specific peak corresponding to ZrO2 was not observed. At the molar ratio [Ag]/[Zr] = 0.25, the particle size of Ag distributed broadly centered at 17 nm for an annealing temperature of 200 °C and at 25 nm for 300 °C. The films annealed in air at 200 °C showed an absorption band centered at 450 nm because of the silver surface plasmon resonance, whereas films heated at 300 °C in air caused a red shift of the absorption to 500 nm. The absorption peak was analyzed using the effective dielectric function of Ag-ZrO2 composite films modeled with the Maxwell-Garnett expression.

Preparation and Characterization of Cu-Doped Zno Sol-Gel Derived Optical Thin Films

2013 ◽  
Vol 802 ◽  
pp. 124-128 ◽  
Author(s):  
Krisana Chongsri ◽  
Siriwattana Aunpang ◽  
Wicharn Techitdheera ◽  
Wisanu Pecharapa
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Sol Gel ◽  
Copper Acetate ◽  
Visible Region ◽  
Ambient Air ◽  
Doping Content ◽  
Acetate Dihydrate ◽  
Cu Doping ◽  
Doped Zno

In this work, we report the preparation of Cu-doped ZnOthin films by sol-gel method based on zinc acetate dihydrate (CH3COO)2Zn·2H2O, Copper acetate dihydrate Cu3(CH3COO)2·H2O) and diethanolamine (HN(CH2OH)2, DEA). The precursor solution was prepared at various Cu composition ranging from 2-20 wt%. All films were spin-coated on borosilicate substrates for several coating repetition followed by annealing process at 550 °C for 4 h in an ambient air. The structural properties of the films were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). The XRD results indicate the domination of hexagonal wurtzite structure of ZnO with noticeable alternation in the XRD peak intensity upon Cu doping content. SEM results revealed the grain size shape and surface morphologies of as-prepared samples. Crucial optical properties of as-prepared films were scrutinized from their UV-Vis transmission spectra. The films are highly transparent in the visible region with more than 90 % transparency within 380 nm to 800 nm. Their corresponding band gaps indicate significant red shift with increasing Cu doping content. Overall results suggest that Cu additive play a vital role on relevant optical properties of ZnO that can be adjusted to meet the requirement for practical optoelectronics applications.

SYNTHESIS AND CHARACTERIZATION OF MICROPOROUS SILICA-ALUMINA THIN FILMS

2010 ◽  
Vol 09 (06) ◽  
pp. 571-574
Author(s):  
CHERAITIA ABDALLAH ◽  
SATHA HAMID ◽  
AYRAL ANDRÉ
Keyword(s):  
Thin Films ◽  
Mixed Oxide ◽  
Sol Gel ◽  
Dip Coating ◽  
Microporous Silica ◽  
Molar Ratios ◽  
Spectroscopic Analyses ◽  
Silica Alumina ◽  
Acidic Alumina

Microporous silica-alumina thin films were prepared by a simple and robust sol-gel method. Tetraethoxysilane was mixed with an acidic alumina hydrosol. Urea was added for the preparation of the alumina hydrosol, for controlling the polycondensation of the mixed oxide network and also as porogen agent. Thin films were deposited by dip-coating on dense substrates. IR and 27 Al NMR spectroscopic analyses showed that for Si/Al molar ratios up to 6/1, a homogeneous mixed oxide is obtained with a random distribution of Al and Si atoms in the oxide lattice based on tetrahedral units. The deposited layers are crack-free as demonstrated by scanning electron microscopy (SEM) observations. Their microporosity was investigated using ellipsoporosimetry (EP) with films supported on flat substrates.

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