A simple sol–gel route to ZrO2 films with high optical performances

ZrO2 films with high optical performances have been deposited via a simple sol–gel route, which involved a controlled hydrolysis-condensation of zirconium (IV) n-propoxide using diethanolamine as the chelating agent and a subsequent spin-coating process. A detailed characterization of the sols and films indicated that, by virtue of light scattering analysis, a good balance between the chelating reactions and hydrolysis-condensation in the colloidal systems could be achieved, and thus the as-deposited films exhibited a comparatively high refractive index of 1.632 (at 632.8 nm). Moreover, the films exhibited large optical band gap of 5.46 eV and high laser-induced damage thresholds of about 36.1 J cm−2 (at 1064 nm, 3 ns pulse duration and R/1 testing mode), which must benefit from their homogeneous and nearly defect-free network structures derived from the simple sol–gel deposition route.