Publication: Synthesis and characterization of niobia doped yttria stabilized zirconia thin film
Date
2009-05-01
Authors
Tan, Wan Cheng
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Semiconductive niobia-doped yttrium stabilized zirconia (Nb2O5-Y2O3-ZrO2) thin film in tetragonal phase was synthesized through a chemical route. When study about the effect of niobium doping in improving the electronics conductivity of the thin film was carried out. The homogeneous, minimum pinholes and cracks Nb2O5-Y2O3-ZrO2 thin films were synthesized by a low cost, low processing temperature, easy coating and versatile doping method. Sol-gel method was performed in this research to produce Nb2O5-Y2O3-ZrO2 thin films. Precursor solution was prepared from a mixture of zirconium n-propoxide (Zr(OC3H7)4), n-propanol, yttrium (III) isopropoxide (Y(OC3H7)3), toluene, niobium (V) ethoxide (Nb(OC2H5)5) and absolute ethanol. Acetic acid and acetylacetone were used as chelating agents, whereas nitric acid and HCl were used as catalysts for the precursor solution. The effect of synthesis amount, deionised (DI) water amount and annealing temperature on the samples were investigated. The samples were characterized using scanning electron microscope (SEM), energy dispersive spectrometer (EDS), x-ray diffraction techniques (XRD), ultraviolet-visible spectroscopy (UV-Vis) and thermo gravimetric/ differential thermal analysis (TG/DTA). The presence of chelating agents and catalysts altered the process of the hydrolysis and condensation reactions. Further addition of DI water enhanced the reactions in the sol. The optical bandgap of niobia-doped YSZ thin film was greatly improved (1.25 eV) and was lower than the optical bandgap of zirconia thin film (4.29 eV).