High switching speed and coloration efficiency of titanium-doped vanadium oxide thin film electrochromic devices
Lee, Pooi See
Date of Issue2013
School of Materials Science and Engineering
Titanium (Ti)-doped vanadium oxide thin films were fabricated by electrochemical deposition on linear polyethylenimine (LPEI)-modified indium tin oxide-coated glass from mixed vanadium oxide and titanium oxide solutions with different Ti concentrations. The as-prepared films were investigated by X-ray diffraction (XRD), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). The electrochemical behaviour of the films was studied using cyclic voltammetry (CV) in 1.0 M LiClO4/propylene carbonate solution. Electrochromism of the oxide films upon Li-ion intercalation/deintercalation was investigated by transmittance measurements during the CV process. The charge transfer resistance of the Ti-doped vanadium oxide film was systematically analyzed with electrochemical impedance spectroscopy (EIS). The amorphous Ti-doped vanadium oxide film containing 4 mol% Ti exhibited the highest transmittance contrast (Δ%T = Tmax − Tmin) of ca. 51.1%T, and coloration efficiency of 95.7 cm2 C−1 at 415 nm. By increasing the Ti content to 10 mol%, the Ti-doped vanadium oxide film exhibited high switching speed and good cycling reversibility reaching 80% of colouring and bleaching time of 5 and 6 s, respectively. Furthermore, the transmittance contrast drops by only 10% after 600 cycles in a two-electrode system.
DRNTU::Engineering::Materials::Microelectronics and semiconductor materials
Journal of materials chemistry C
© 2013 Royal Society of Chemistry. This is the author created version of a work that has been peer reviewed and accepted for publication by Journal of Materials Chemistry C, Royal Society of Chemistry. It incorporates referee’s comments but changes resulting from the publishing process, such as copyediting, structural formatting, may not be reflected in this document. The published version is available at: [http://dx.doi.org/10.1039/c3tc31508h].