Transparent oled light extraction

Abstract

The present disclosure provides novel light emitting devices including AMOLED displays, based on transparent OLED architecture, where a laminated nanostructured light extraction film can produce axial and integrated optical gains as well as improved angular luminance and color. Generally, the transparent AMOLED displays with laminated sub-micron extractors include: (a) an extractor on a transparent substrate for light outcoupling on both sides of the transparent device; or (b) an extractor on a reflective film for providing light outcoupling off the bottom side of the bottom-emitting (BE) AMOLED; or (c) an extractor on a light absorbing film for providing outcoupling off the bottom side of the BE AMOLED combined with improved ambient contrast.

What is claimed is: 
     
         1 . A light emitting device, comprising:
 an organic light emitting diode (OLED) device having a top electrode and an opposing bottom electrode disposed on a backplane, wherein each of the top electrode, the opposing bottom electrode and the backplane are substantially transparent to light emitted by the OLED device;   a capping layer disposed immediately adjacent the top electrode; and   a light extraction film disposed adjacent the capping layer,   wherein the light extraction film comprises a substrate comprising a material substantially transparent to light emitted by the OLED device, such that a portion of the light emitted by the OLED device passes through the substrate and a portion of the light emitted by the OLED device passes through the backplane, a layer of nanostructures applied to the substrate, and a backfill layer disposed over the nanostructures and adjacent the capping layer, the backfill layer having an index of refraction greater than the index of refraction of the nanostructures.   
     
     
         2 . The light emitting device of  claim 1 , wherein the material substantially reflective to light emitted by the OLED device comprises a reflective metal, an inorganic dielectric stack, a polymeric multilayer film, or a combination thereof. 
     
     
         3 . The light emitting device of  claim 1 , wherein the backfill layer comprises an adhesive for bonding the light extraction film to the capping layer. 
     
     
         4 . The light emitting device of  claim 1 , further comprising an adhesive optical coupling layer disposed immediately adjacent the capping layer. 
     
     
         5 . The light emitting device of  claim 1 , wherein the layer of nanostructures are applied to the substrate by embossing into a major surface of the substrate. 
     
     
         6 . The light emitting device of  claim 1 , wherein the layer of nanostructures are applied to the substrate by patterning a coating. 
     
     
         7 . The light emitting device of  claim 1 , wherein the layer of nanostructures comprise particulate nanostructures, non-particulate nanostructures, or a combination thereof. 
     
     
         8 . The light emitting device of  claim 11 , wherein the non-particulate nanostructures comprise an engineered nanoscale pattern. 
     
     
         9 . The light emitting device of  claim 1 , wherein the backfill layer comprises a non-scattering nanoparticle filled polymer. 
     
     
         10 . The light emitting device of  claim 1 , wherein at least one of the top electrode and the opposing bottom electrode comprises a transparent conductive oxide. 
     
     
         11 . The light emitting device of  claim 14 , wherein the transparent conductive oxide comprises a thickness less than about 300 nm. 
     
     
         12 . The light emitting device of  claim 14 , wherein the transparent conductive oxide comprises a thickness less than about 100 nm. 
     
     
         13 . The light emitting device of  claim 14 , wherein the transparent conductive oxide comprises a thickness less than about 30 nm. 
     
     
         14 . The light emitting device of  claim 1 , wherein the capping layer comprises a material having a refractive index greater than about 1.7. 
     
     
         15 . The light emitting device of  claim 1 , wherein the capping layer comprises molybdenum oxide, indium tin oxide, zinc selenide, or a combination thereof. 
     
     
         16 . The light emitting device of  claim 1 , wherein the capping layer comprises a thickness between about 60 nm and 400 nm. 
     
     
         17 . The light emitting device of  claim 1 , wherein the light extraction film comprises nanostructures having a variable pitch. 
     
     
         18 . The light emitting device of  claim 1 , wherein the light extraction film comprises nanostructures having a pitch of about 400 nm, about 500 nm, about 600 nm, or a combination thereof. 
     
     
         19 . An active matrix organic light emitting diode (AMOLED) device, comprising:
 an array of light emitting devices, each light emitting device comprising:
 an organic light emitting diode (OLED) device having a top electrode and an opposing bottom electrode disposed on a backplane, wherein each of the top electrode, the opposing bottom electrode and the backplane are substantially transparent to light emitted by the OLED device; 
 a capping layer disposed immediately adjacent the top electrode; and 
   a light extraction film disposed over the array of light emitting devices, the light extraction film adjacent the capping layer,   wherein the light extraction film comprises a substrate comprising a material substantially transparent to light emitted by the OLED device, such that a portion of the light emitted by the OLED device passes through the substrate and a portion of the light emitted by the OLED device passes through the backplane, a layer of nanostructures applied to the substrate, and a backfill layer disposed over the nanostructures and adjacent the capping layer, the backfill layer having an index of refraction greater than the index of refraction of the nanostructures.   
     
     
         20 . An image display device, comprising:
 a plurality of light emitting devices, each light emitting device comprising:
 an organic light emitting diode (OLED) device having a top electrode and an opposing bottom electrode disposed on a backplane, wherein each of the top electrode, the opposing bottom electrode and the backplane are substantially transparent to light emitted by the OLED device; 
 a capping layer disposed immediately adjacent the top electrode; 
   a light extraction film disposed adjacent the capping layer; and   an electronic circuit capable of activating each of the light emitting devices, wherein the light extraction film comprises a substrate comprising a material substantially transparent to light emitted by the OLED device, such that a portion of the light emitted by the OLED device passes through the substrate and a portion of the light emitted by the OLED device passes through the backplane, a layer of nanostructures applied to the substrate, and a backfill layer disposed over the nanostructures and adjacent the capping layer, the backfill layer having an index of refraction greater than the index of refraction of the nanostructures.