Optical and Electrochemical Properties of Sol-gel Spin Coated CeO2-TiO2 Films

TitleOptical and Electrochemical Properties of Sol-gel Spin Coated CeO2-TiO2 Films
Publication TypeConference Paper
Year of Publication1995
AuthorsNilgün Özer, Selmar DeSouza, Carl M Lampert
Conference NameSPIE Meeting
Date Published07/1995
Conference LocationSan Diego, CA
Keywordscerium oxide-titanium oxide, counter electrode, electrochemical properties, electrochromic device, optical properties, sol-gel deposition

The optical and electrochemical properties of sol-gel spin coated Ce02-TiO2 (50% CeO2) films were investigated for electrochrornic applications. The coating solutions were prepared by using mixed organic-inorganic | Ti(OC2H5)4 and Ce(NH4)2 (NO3)6 | precursors. X-ray diffraction studies showed the sol-gel spin-coated films were composed of an amorphous matrix of titanium oxide containing nanocrystallites of cerium oxide. The coating solar transmission value was Ts=0.8 (250 nm thick). The refractive index and the extinction coefficient were derived from transmittance measurements in the UV-VIS-NIR regions. These films had refractive index value of n=2.18 and extinction coefficient value of k=8x10-4 at λ=550 nm. Cyclic voltametric measurements showed reversible electrochemical insertion of lithium ions in a CeO2-TiO2/LiClO4-propylene carbonate electrochemical cell. During cycling the films maintain high optical transmittance. Spectrophotometric and electrochemical investigations performed on CeO2-TiO2 films revealed that these films are suitable as an optically passive counter-electrode in lithium electrochromic devices.

LBNL Report Number