Sol-gel based antireflective (AR) coatings with controllable pore size using organic nanocrystals and dendrimers

摘要

Embodiments of the invention relate generally to methods and compositions for forming porous low refractive index coatings on substrates. In one embodiment, a method for forming a porous coating on a substrate is provided. The method comprises coating a substrate with a sol-gel composition, comprising at least one porosity forming agent, wherein the porosity forming agent is selected from at least one of dendrimers and organic nanocrystals and removing the at least one porosity forming agent to form the porous coating. Use of at least one of the dendrimers and organic nanocrystals leads to the formation of stable pores with larger volume fraction in the film. Further, the size and interconnectivity of the pores may be controlled via selection of the organic nanocrystal or dendrimer structure, the total organic nanocrystal or dendrimer molecule fraction, polarity of the organic nanocrystal or dendrimer molecule and solvent, and other physiochemical properties of the gel phase.