In the last two decades several researchers focused on the possibility to replace inorganic photonic crystals with polymer ones. Photonic crystals are dielectric lattices able to modify photon flow thanks to the periodical modulation of refractive index. This peculiarity has been largely employed for several applications including emission control, photon recycling, light harvesting enhancement, sensing and so on. While vacuum-deposited inorganic structures, thanks to high dielectric contrast, provide undiscussed performances, polymer ones are easier to fabricate and possess mechanical properties unconceivable with their inorganic analogous. Thus achieving the processability of polymers with highly inorganic systems can generate a new paradigm in the field.<br/>In this work, we report a new hybrid photonic structure fabricated by dynamic spin-coating of alternated layers of polymers as low refractive index material and hybrid polymer-titania thin films as the high refractive index one. The latter are prepared using a sol-gel route where an alkoxy precursor of the oxide is mixed to a polymer rich in acidic carboxyl groups. The precursor’s solution allows the formation of a gel-like structure once deposited via spin-coating that is then converted into a solid hybrid film by simple thermal annealing on a hot-plate. The new procedure allows the fabrication of Bragg stacks with optical properties unconceivable with standard polymer systems but maintaining the processability of these materials. A full optical and morphological characterization is also provided. Furthermore, we also demonstrate the possibility to introduce engineered defect in the dielectric lattices doped with emitting polymers to form a microcavity, able to modify the emission of the dye.<br/>These results are promising for the fabrication of high dielectric contrast photonic structure with processability and mechanical properties typical of polymers and performances of inorganic materials commonly processed with high vacuum technologies.

High dielectric contrast hybrid polymer-inorganic planar photonic crystals

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.