Lithiation and electrochromic characteristics of composite Ta2O5-TiO2 films fabricated by ultraviolet reactive laser ablation

Composite Ta2O5-TiO2 films have been deposited on indium tin oxide coated glass by pulsed laser reactive ablation in the O-3/O-2 ambient gases, and different molar ratio Ta/Ti of composite films were prepared using the superposed tantalum and titanium sheets with a suitable selection of the area ratio as a target. Electrochemical and electrochromic behaviors of composite Ta2O5-TiO2 electrodes are investigated by cyclic voltammetry and irt situ visible transmittance measurements. Results show that the composite film with the presence of small amounts of TiO2 within Ta2O5 can significantly improve electrochemical and electrochromic properties. The composite Ta2O5-TiO2 film with Ta/Ti ratio of 4.3 exhibits excellent electrochromic efficiency of 72 cm(2)/C at 500 nm, and shows superior insertion capability of Li ions to pure Ta2O5 and TiO2. (C) 2000 The Electrochemical Society. S0013-4651(99)09-037-0. All rights reserved.