Surface morphology, electrochemical and electrical performances of ZnO thin films sensitized with Ag nanoparticles by UV irradiation

In this work, we synthesized Ag nanoparticles on TiO2 thin films deposited on soda lime glass substrates. Ag nanoparticles were synthesized by photoreduction under UV irradiation silver nitrate solution. X-ray diffraction, Raman spectroscopy, scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) measurements were used for physicochemical characterization. The structural study showed that all samples were polycrystalline, main phases were anatase and rutile, and no additional signals were detected after surface modification. Raman spectroscopy suggested that silver aggregates deposited on the TiO2 films could exhibit the surface plasmon resonance (SPR) phenomenon; XPS and SEM analysis confirmed TiO2 film morphological modification after photoreduction process. Photocatalytic degradation of methylene blue (MB) was studied under UV irradiation in aqueous solution, and, besides, pseudo-first-order model was used to obtain kinetic information about photocatalytic degradation. Results indicated that Ag-TiO2 showed an important increase in photocatalytic activity under UV (from 20% to 35%); finally, Ag-TiO2 thin films had kapp value 2.4 × 10−3 ± 0.003 min−1 of 1.8 times greater than the kapp value 1.3 × 10−4 ± 0.0004 min−1 of TiO2 thin films.

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Morphology Evolution Of ZnO Thin Films Deposited By Nitrogen Mediated Crystallization Method

MATEC Web of Conferences ◽

10.1051/matecconf/201815902031 ◽

2018 ◽

Vol 159 ◽

pp. 02031 ◽

Cited By ~ 1

Author(s):

Iping Suhariadi ◽

Masaharu Shiratani ◽

Naho Itagaki

Keyword(s):

Thin Films ◽

Surface Morphology ◽

Deposition Process ◽

Zno Thin Films ◽

Nitrogen Flow ◽

Force Microscopy ◽

Crystallization Method ◽

Power Spectral ◽

Density Analysis ◽

Skewness And Kurtosis

We study the surface morphology of ZnO thin films deposited by nitrogen mediated crystallization method utilizing atomic force microscopy as a function of nitrogen flow rates. Initially, the surface morphology of ZnO thin film deposited without nitrogen exhibits a bumpy surface with spiky grains where the skewness and kurtosis values were found to be 0.48 and 4.80, respectively. By addition of small amount of nitrogen, the skewness and kurtosis values of the films significantly decrease associated with a flatter topography. Further increase in nitrogen flow rate to 16 sccm has roughened the surface shown mainly by the increase in kurtosis value to be 3.30. These results indicate that the addition of small amount of nitrogen during deposition process has enhanced the adatoms migration on the surface resulting in a superior film with a larger grain size. Two-dimensional power spectral density analysis reveals that all the films have self-affine fractal geometry with total fractal values in the range of 2.14 to above 3.00.

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Strong Volta potential change in doped zinc oxide as a photoresponse to UV irradiation

RSC Advances ◽

10.1039/c9ra01758e ◽

2019 ◽

Vol 9 (61) ◽

pp. 35579-35587 ◽

Cited By ~ 1

Author(s):

Silvia Huber ◽

Cezarina Cela Mardare ◽

Andrei Ionut Mardare ◽

Christoph Kleber ◽

Achim Walter Hassel

Keyword(s):

Thin Films ◽

Zinc Oxide ◽

Uv Irradiation ◽

Potential Change ◽

Zno Thin Films ◽

Volta Potential ◽

Doped Zno

Doped ZnO thin films on ITO substrates were prepared by reactive co-sputtering of ZnO and several dopant metals, namely Al, Mn, Ti, W or Zr.

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

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.675-676.241 ◽

2016 ◽

Vol 675-676 ◽

pp. 241-244 ◽

Cited By ~ 1

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.

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Electrical Properties of Pulsed Laser Deposited ZnO Thin Films

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.67.121 ◽

2009 ◽

Vol 67 ◽

pp. 121-125

Author(s):

Chattopadhyay Sourav ◽

Kumar Nath Tapan

Keyword(s):

Thin Films ◽

Surface Morphology ◽

Substrate Temperature ◽

Hall Mobility ◽

Pulsed Laser ◽

Deposition Process ◽

Zno Thin Films ◽

Zno Films ◽

Visible Absorption ◽

Substrate Temperatures

Epitaxial Single-crystal ZnO thin films have been grown on c-plane (0001) sapphire by Pulsed Laser Deposition process at different substrate temperatures (300 – 800 °C) with 10-1 mbar oxygen pressure. The thicknesses of the films have been varied by varying number of pulses with a repetition rate of 10 pulse/sec. It is found that the sheet resistivity of ZnO thin films grown on c-plane sapphires are in the order of 10-2 Ω-cm and it increases with increasing substrate temperatures and film thickness. The carrier concentrations and Hall mobility are found to be in the order of 1017 cm-3 and ~195 cm2/V-s, respectively. The Hall mobility slightly decreases with increase of substrate temperature and thickness of the films. It is also found that the ZnO films are structurally uniform and well oriented with perfect wurtzite structure with c/a ratio 5.1. We have also deposited non-epitaxial ZnO films on (100) p-Silicon substrates at the same conditions. From HR FE-SEM micrographs, surface morphology of ZnO films grown at lower substrate temperature are found to be uniform compared to the films grown at higher temperatures showing non-uniformity and misoriented wurtzite structures. However, the surface morphology of ZnO flims grown epitaxially on (0001) sapphire are found to be more uniform and it does not change much with growth temperature. The resistivity of the films grown on p-Silicon at higher temperatures is in the order of 103 Ω-cm whereas films grown at lower substrate temperatures show comparatively lower resistivities (~ 102 Ω-cm). From the recorded UV-Visible absorption spectrum the band gap of the film has been estimated to be 3.38 eV.

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