Sol-gel films doped with semiconductor nanocrystals for optical applications

Sol-gel films doped with MeS (Me = Cd or Pb) nanocrystals or with MxOy (M = Ni or Co) nanocrystals have been fabricated. Two different strategies were used: for the sulfides a colloidal doping sol was prepared at room temperature and then mixed with the matrix sol. For the oxides a bifunctional ligand was used, bearing either an amine group capable of coordinating the M ions and hydrolysable siloxane groups for anchoring the metal complex moiety to the silicate matrix. In this case the oxide nanocrystals precipitate at 500degreesC. Films containing MeS nanocrystals showed both non-linear and active optical properties. Nanocomposite films doped with MxOy showed optical gas sensing properties.