Fabrication of photo-cross-linked stable organic-inorganic hybrid second-order nonlinear optical films

A photo-cross-linked stable organic-inorganic hybrid second-order nonlinear optical (NLO) film was fabricated by sol-gel process with silicon sol linking aromatic diazonium group (SOD) and Chromophore molecule 2-((4-[4-(2-carboxy-2-cyano-vinyl)-phenylazo]-phenyl)-methyl-amino)-ethyl acid (DRCB). The films were poled under 50DC voltage electric field at room temperature at the existence of solvents. After the solvents volatilized completely and upon UV irradiation under the electric field, the ionic bonds converted to stable covalent bonds in the system, the orientations of the chromophores were fixed by the photo-cross-linked structures. The order parameter of the fabricated film can retain 99% after 17days at room temperature. The stable organic-inorganic hybrid photo-cross-linked NLO films fabricated in this paper had large potential to be applied in electric-optic devices. (c) 2008 Elsevier B.V. All rights reserved.