Light extraction film with nanoparticle coatings

US7957621B2 · kind B2 · utility

Assignee

• 3M INNOVATIVE PROPERTIES COMPANY · US

Inventors

• Jun-Ying Zhang · Perrysburg, US
• Jimmie R. Baran, Jr. · Prescott, US
• Terry L. Smith · Plainfield, US
• William J. Schultz · North Oaks, US
• William Blake Kolb · Windom, US
• Cheryl A. Patnaude · Mendota Heights, US
• Sergey Lamansky · Redmond, US
• Brian K. Nelson · Shoreview, US
• Naiyong Jing · Woodbury, US
• Brant U. Kolb · Afton, US

Key dates

• Filing date: Dec 17, 2008
• Grant date: Jun 7, 2011
• Expiry date: Dec 17, 2028

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10K2102/331
• WIPO field: Micro-structural and nano-technology
• WIPO sector: Chemistry

Abstract

A multifunctional optical film for enhancing light extraction includes a flexible substrate, a structured layer having nanoparticles of different sizes, and a backfill layer. The structured layer effectively uses microreplicated diffractive or scattering nanostructures located near enough to the light generation region to enable extraction of an evanescent wave from an organic light emitting diode (OLED) device. The backfill layer has a material having an index of refraction different from the index of refraction of the structured layer. The backfill layer also provides a planarizing layer over the structured layer in order to conform the light extraction film to a layer of an OLED display device. The film may have additional layers added to or incorporated within it to an emissive surface in order to effect additional functionalities beyond improvement of light extraction efficiency.