PROPERTIES OF SPUTTERED THIN-FILMS OF VANADIUM TITANIUM-OXIDE FOR USEIN ELECTROCHROMIC WINDOWS

Thin films of various compositions of VzTi1-zOy have been deposited by RF-diode sputtering. A variety of optical and electrochemical measure ments have been carried out to determine their suitability to perform as counter electrodes (CE) in electrochromic windows. It has been foun d that in general, the films containing higher vanadium concentrations have higher charge capacities, which are seen to be easily sufficient to make useful CE layers in electrochromic windows. The electrochromi c behaviour of the VzTi1-zOy films themselves is seen to be quite comp licated, and does not fit a first order theory. A simple theoretical m odel based on electrons being localised preferentially on vanadium ato ms is given, which goes some way towards explaining this behaviour. (C ) 1997 Elsevier Science S.A.