PLD of thin electrochromic WO3 films at room temperature

Abstract

The amorphous dielectric WO₃films have been obtained by the droplet-free pulsed laser deposition method on the quartz and c-sapphire substrates at room temperature and the oxygen pressure from 20 to 60 mTorr. The dependence of the parameters of the obtained films on the oxygen pressure during the growth has been established. The transmission of the WO₃ films increases over the whole region under study from 200 to 1000 nm with increase of the oxygen pressure in the process of the film growth on the substrates of both types. The surface roughness of the films poorly depended on the oxygen pressure during the film deposition and was 4-5 nm. The thin-film electrochromic cell with a liquid electrolyte was produced on the basis of the obtained WO₃ film. The cell transmission over the spectrum range from 300 to 900 nm is reduced by 30% at a voltage of 2.5 V during the staining time of the order of two minutes.