Fluorine-doped ZnO thin films deposited by spray pyrolysis technique

Fluorine doped ZnO thin films (FZO) are prepared onto glass substrates at 350 degrees C by the chemical spray pyrolysis technique. X-ray diffraction spectra show a polycrystalline of ZnO (wurtzite structure) where the amount of fluorine doping affects to preferential orientation (002 plane along c-axis) and does not vary the lattice parameters. Therefore, F introduction in lattice is by the substitution of O(-2) ions by F(-1) ions. Any variation is observed in transmittance and reflectance measurements in 400-2000 nm wavelength range when samples present F dopant; they have transmittance around 80% in the near infrared and visible zones. The FZO films are degenerate and exhibit n-type electrical conductivity. The best resistivity and mobility are 7.6 x 10(-3) Omega cm and 3.77 cm(2) V(-1) s(-1) respectively. The calculated values of the mean free path are very small compared to the grain sizes calculated using XRD measurements. Therefore, we suggest that ionized impurity and/or neutral impurity scattering are the dominant scattering mechanisms in these films

Structural, optical, and electrical properties of Yb-doped ZnO thin films prepared by spray pyrolysis method

Yb-doped ZnO thin films were prepared on glass substrates by spray pyrolysis technique in order to investigate the insertion of Yb ions in the ZnO matrix and the related optical properties of the films. The molar ratio of Yb in the spray solution was varied in the range of 0-5 at. %. X-ray diffraction patterns showed that the undoped and Yb-doped ZnO films exhibit the hexagonal wurtzite crystal structure with a preferential orientation along [002] direction. No secondary phase is observed in Yb-doped ZnO films. All films exhibit a transmittance between 75 and 90% in the visible range with a sharp absorption onset about 375 nm corresponding to the fundamental absorption edge at 3.3 eV. The photoluminescence measurements show a clear luminescence band at 980 nm that is characteristic of Yb(3+) transition between the electronic levels (2)F(5/2) and (2)F(7/2). This is an experimental evidence for an efficient energy transfer from ZnO matrix to Yb(3+). Hall effect measurements showed low resistivities and high carrier mobilities which makes these films of interest to photovoltaic devices.This work is supported by the program interdisciplinaire énergie du CNRS Grant No. PE10-2.1.2-2

Structural, Optical and Electrical Properties of Transparent Conducting Oxide Based on Al Doped ZnO Prepared by Spray Pyrolysis

Aluminum doped zinc oxide (AZO) thin films were deposited on glass substrates at 350 °C by spray pyrolysis technique. X-ray diffraction patterns show that the undoped and AZO films exhibit the hexagonal wűrtzite crystal structure with a preferential orientation along 2 direction. AFM images showed that AZO film with 3 % of Al has a uniform grain sizes with a surface roughness of about 24 nm. All films present a high transmittance in the visible range. Both undoped and AZO films were n-type degenerate semiconductor and the best electrical resistivity value was around 8.0 ´ 10- 2 W.cm obtained for 3 % Al content

Elaboration and Characterization of Sprayed Tb-Doped ZnO Thin Films

ZnO and Tb-doped ZnO (TZO) thin films were deposited on glass substrate at 350 °C by spray pyrolysis technique. Structural, optical and electrical properties of the films were investigated as a function of dopant concentration, which was varied between 0 and 5 at % of terbium. TZO films were polycrystalline and exhibit hexagonal quartzite crystal structure with a preferential orientation along 2 direction. The AFM measurements show that the roughness of the films increased with Tb doping. All the TZO films exhibit a transmittance between 70 and 80 % in the visible range. The TZO films were n-type degenerate semiconductor with a lowest electrical resistivity of about 6.0´10- 2 W.cm

Structural Characterization of Electrodeposited Nanostructured Titanium Dioxide thin Films on Stainless Steel and on Indium Tin Oxide (ITO)

Nanostructured TiO2 thin films are fabricated directly by an anodic electrodeposition using an aqueous TiCl3 solution. TiO2 thin films were deposited on stainless steel (SS) and indium tin oxide (ITO) substrates. As deposited, all TiO2 films were amorphous. For TiO2/stainless annealed at 350 °C, XRD patterns show both anatase and rutile phases. While, only anatase phase subsists for annealing temperature at 450 °C and 500 °C. The calculated grain sizes are around 20 nm. By AFM analysis, surface root mean square (rms) roughness obtained for TiO2 /Steel is around 56 nm and decrease with annealing to 30 nm. For TiO2 thin films deposited on ITO and annealed at 350, 450, and 500 °C, only orthorhombic single phase is observed with grains size of about 25 nm. The rms of as- deposited TiO2/ITO around 60 nm decrease with annealing to 40 nm confirming that annealing process improves the roughness of the as deposited samples

Investigation of the structural, optical and electrical properties of Nd-doped ZnO thin films deposited by spray pyrolysis

Neodymium-doped zinc oxide (NZO) thin films were deposited on glass substrates by spray pyrolysis technique. X-ray diffraction patterns have shown that both undoped and Nd-doped ZnO films exhibit the hexagonal wurtzite crystal structure with a preferential orientation along [0 0 2] direction. The effective doping concentration has been determined by Rutherford backscattering measurements showing that the neodymium is not incorporated easily into ZnO host matrix. The surface roughness was shown to increase with Nd doping. NZO films are highly transparent in the visible region. The lowest electrical resistivity value of about 4.0 10−2 Ω cm was obtained for 1% Nd effective doping

Structural Transition in SrZnO Laser Pulse Deposited Alloy

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