Fabrication of electrochromic displays by chemically vapor depositing and patterning WO_3 films on SnO_2:F covered glass substrates

摘要

It has been suggested in the past (1,2) that electrochromism in WO_3 films is divided in two parts: a fast electronic one,during which the film is colored by electronic injection and a slower one associated with the insertion of ions in it.The presence of electrons only in the WO_3 film causes the splitting of the conduction band in two sub-bands (the so-called Hubbard bands (1,2)).Electronic oscillations between these two bands cause photon absorption leading to film coloration.In this work the fabrication of electrochromic displays based on chemically vapor deposited (CVD) WO_3 films is described.Their electrochrromic performance is reported and discussed when biased with DC and AC voltage,in view of the above suggestion.