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Structural and optoelectronic properties of vanadium pentoxide thin films deposited by ultrasonic spray pyrolysis.

Koç, Şeyma
Nanocrystalline vanadium pentoxide (V2O5) thin films were deposited onto fluorine doped tin oxide (FTO) coated glass substrates using ultrasonic spray pyrolysis and spin coating methods. The formation behavior of thin films, the effects of different production methods on the characteristics of the films and their microstructural / physical properties were investigated as a function of annealing temperature in the range of 450-550 °C and other controllable process parameters. Structural, morphological and optoelectronic properties of orthorhombic V2O5 films were examined by X-Ray diffraction, Raman spectroscopy, X-Ray photoelectron spectroscopy, scanning electron microscope, atomic force microscopy, UV-VIS spectroscopy and CV measurements. It was clear that homogeneous thin films were obtained in a reproducible manner through ultrasonic spray deposition. Particle size of the films was found to increase with the annealing temperature .Optical transmittance of the films got adversely affected as the roughness increased. All heat treated films showed electrochromic (EC) response and for films with a thickness of 50 nm, the transmittance change was about %10 at a wavelength of 800 nm. Ultrasonic spray deposition method was utilized as a reproducible and cost-effective method. Parametric optimization approach represented herein this thesis for the ultrasonic spray deposition of V2O5 thin films can be easily applied to other oxide systems.