Pr. Bueno et al., Electrochromic properties of undoped and lithium doped Nb2O5 films prepared by the sol-gel method, ELECTR ACT, 46(13-14), 2001, pp. 2113-2118
The electrochromic properties of lithium doped niobium pentoxide films prep
ared by the sol-gel route were analyzed. The electrochemical responses of t
he films exhibited a strong dependence on the lithium doping level. They we
re evaluated by monitoring the electrode mass change observed during cyclic
voltammetry and chronoamperometry measurements, using the electrochemical
quartz crystal microbalance. The electrochromic properties of the films, in
vestigated by in situ spectroelectrochemical measurements, indicated that t
he bleaching process in the lithium doped films was complete whereas in the
pure Nb2O5 films a residual coloration was observed, An increase in the li
thium doping level improved the electrochemical and optical performances of
the oxide film electrodes and a higher mass change was observed during the
insertion/deinsertion measurements, so the maximum anodic charge that coul
d be associated with a faster bleaching process was observed for films with
the highest lithium doping level. (C) 2001 Elsevier Science Ltd. All right
s reserved.