Inverse conjugated polymer opals and their luminescent spectra

Colloidal silica spheres are usually used for making opal photonic crystals. With the aim to create tunable or otherwise functional opals we have coated colloidal SiO 2 spheres with conjugated polymers, including: polyaniline sulfonic acid, polypyrrole and MEH-PPV (poly [2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylenevinylene]). Spheres coated with MEH-PPV were dispersed in H 2 O and coated with polyelectrolytes that charged the colloidal surfaces allowing the polymer coated spheres to self-assemble by sedimentation under gravity into close packed structures with well ordered crystalline domains. Inverse MEH-PPV/polypropylene photonic crystals were fabricated and their photoluminescence was blue shifted compared to a uniform MEH-PPV film.