Bulg. J. Phys. vol.40 no.3 (2013), pp. 253-257

Temperature Tuning of Optical Properties of High Refractive Index Metal Oxide Films Obtained by the Sol-Gel Method

T. Babeva, K. Lazarova, M. Vasileva, B. Gospodinov, J. Dikova
"Acad. J. Malinowski" Institute of Optical Materials and Technologies, Bulgarian Academy of Sciences, Acad. G. Bonchev Str. Bl. 109, 1113 Sofia, Bulgaria
Abstract. The present study reports on the deposition and characterization of thin Ta2O5, TiO2 and Nb2O5 film, obtained by the sol-gel method using tantalum ethoxide, titanium isopropoxide and niobium chloride as precursors and specially developed water free sol-gel procedure. Structure and morphology of the films were inspected trough XRD and SEM measurements. Refractive index, extinction coefficient and thickness of the films were determined from reflectance spectra using non-linear curve fitting method. Refractive index values as high as 1.85, 2.07 and 2.17 were obtained for Ta2O5, TiO2 and Nb2O5 film, respectively at wavelength of 600 nm. The possibility of controlled tuning of optical properties by appropriate annealing was demonstrated and discussed.

Full-text: PDF

go back