Light extraction film with nanoparticle coatings

A multifunctional optical film for enhancing light extraction from a self-emissive light source, comprising:

• a flexible substrate;
• a structured layer of extraction elements having a first index of refraction, wherein a substantial portion of the extraction elements are in optical communication with a light emitting region of the self-emissive light source when the optical film is located against the self-emissive light source,
• wherein the extraction elements comprise agglomerations of nanoparticles disposed in a surface layer manner on the substrate, and the extraction elements form a non-planar surface of the structured layer, and
• wherein the agglomerations of nanoparticles comprise first nanoparticles having diameters within a first range and second nanoparticles added to the first nanoparticles and having diameters in a second range less than and non-overlapping with the first range;
• and
• a backfill layer comprising a material having a second index of refraction different from the first index of refraction, wherein the backfill layer forms a planarizing layer over the extraction elements on the non-planar surface of the structured layer.