Optical and electrochemical properties of sol-gel spin-coated CeO2-TiO2 films

摘要

Abstract: The optical and electrochemical properties of sol-gel spin coated CeO$-2$/-TiO$-2$/ (50% CeO$-2$/) films were investigated for electrochromic applications. The coating solutions were prepared by using mixed organic-inorganic $LB@Ti(OC$-2$/H$-5$/)$-4$/ and Ce(NH$- 4$/)$-2$/ (NO$-3$/)$-6$/$RB 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 T$-s$/ $EQ 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 $EQ 2.18 and extinction coefficient value of k $EQ 8 $MUL 10$+$MIN@4$/ at $lambda $EQ 550 nm. Cyclic voltametric measurements showed reversible electrochemical insertion of lithium ions in a CeO$-2$/-TiO$-2$//LiClO$-4$/-propylene carbonate electrochemical cell. During cycling the films maintain high optical transmittance. Spectrophotometric and electrochemical investigations performed on CeO$-2$/-TiO$-2$/ films revealed that these films are suitable as an optically passive counter-electrode in lithium electrochromic devices. !13