Sol-gel coatings for optoelectronic devices

Abstract

Nb2O5 prepared by a sol-gel process in form of coatings and aerogels are new materials which present interesting properties: (a) 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), (b) they are semiconductor and present a photoelectric effect when illuminating in the UV region (ë < 360 nm). These films are therefore very promising to be used in electrochromic devices, as electrodes for photoelectrochemical purpose and the development of nanocrystalline solar cell, and (c) when prepared in aerogel form, the high BET surface area of the powders is a promising asset to use these new materials for catalytic purposes.