Patent ID: 8659221

Claim:
A light extraction film for enhancing light output from an organic light emitting diode (OLED) device, comprising: a flexible substrate substantially transparent to light emitted by the OLED device; a layer of engineered nanostructures applied to the substrate and having multi-periodic zones; and a backfill layer applied over the nanostructures and forming a substantially planar surface on a surface of the backfill layer opposite the nanostructures, wherein the backfill layer has an index of refraction greater than an index of refraction of the nanostructures, wherein the multi-periodic zones comprise a repeating zone of the nanostructures where the zone comprises a first set of nanostructures having a first periodic pitch and a second set of nanostructures having a second periodic pitch different from the first periodic pitch, wherein the first set of nanostructures have a first height, a first aspect ratio, and a first shape, and the second set of nanostructures have a second height, a second aspect ratio, and a second shape, wherein at least one of the first height, the first aspect ratio, and the first shape is different from, respectively, the second height, the second aspect ratio, and the second shape.