Niobia sol-gel : a new material for electrochromic and photoelectric applications

Abstract

Nb2O5 prepared by a sol-gel process in the form of coatings are new materials which have outstanding properties: (1) The coatings present electrochromic properties and exhibit a blue coloration under Li+ insertion with 100% reversible variation of the optical transmission in the visible and near infrared range between 80% and 20% and have a high chemical stability (tested up to 2000 cycles). (2) They are semiconductors and present a photoelectric effect when illuminating in the UV region ((lambda) < 360 nm). These films are therefore very promising for use in electrochromic devices and as electrodes for photoelectrochemical purposes and the development of nanocrystalline solar cells.