| abstract |
A method for forming a substantially transparent nanoporous organosilicate film on a substantially transparent substrate, for use in optical lighting devices such as organic light emitting diodes (OLEDs). The method includes first preparing a composition comprising a silicon containing pre-polymer, a porogen, and a catalyst. The composition is coated onto a substrate which is substantially transparent to visible light, forming a film thereon. The film is then gelled by crosslinking and cured by heating, such that the resulting cured film is substantially transparent to visible light. It is preferred that both the substrate and the nanoporous film are at least 98% transparent to visible light. Optical devices which include the resulting structures of this invention exhibit improved light extraction and illuminance where the nanoporous organosilicate film has a low refractive index in the range of 1.05 to 1.4, serving as an impedance matching layer in such devices. |