Light-emtting diode display devices with uv-cured layer

Abstract

A light-emitting diode (LED) structure includes a light-emitting diode including an emissive electroluminescent layer situated between two electrodes, a light extraction layer (LEL) comprising a UV-cured ink, and a UV blocking layer between the LEL and the light-emitting diode. The UV blocking layer has a thickness of 50-500 nm and at least 90% absorption to UV light of wavelengths for curing the UV-cured ink.

What is claimed is: 
     
         1 . A light-emitting diode (LED) structure comprising:
 a light-emitting diode including an emissive electroluminescent layer situated between two electrodes;   a light extraction layer (LEL) comprising a UV-cured ink; and   a UV blocking layer between the LEL and the light-emitting diode, the UV blocking layer having a thickness of 50-500 nm and at least 90% absorption to UV light of wavelengths for curing the UV-cured ink.   
     
     
         2 . The structure of  claim 1 , wherein the LEL layer has a thickness of up to 5 μm. 
     
     
         3 . The structure of  claim 1 , wherein the UV blocking layer comprises organic charge transport molecules. 
     
     
         4 . The structure of  claim 1 , wherein the organic charge transport molecules comprise one or more of: N, N′-diphenyl-N, N′-bis(3-methylphenyl); (1,1′-biphenyl)-4,4′-diamine; N,N′-Di(1-naphthyl)-N,N′-diphenyl-(1,1′-biphenyl)-4,4′-diamine; N,N′-bis(1-phenanthrene)-N,N′-diphenyl-1,1′-biphenyl-4,4′-diamine; N,N′-bis(phenanthren-9-yl)-N,N-bis(phenyl)-benzidine; N,N′-Di-[(9-phenanthrenyl)-N,N′-diphenyl]-1,1′-biphenyl-4,4′-diamine; 4,7-Diphenyl-1,10-phenanthroline; bis(8-hydroxy-2-methylquinoline)-(4-phenylphenoxy)aluminum, tris-(8-hydroxyquinoline)aluminum; Tetracene; 4-phenyl; or 6-phenyl. 
     
     
         5 . The structure of  claim 1 , wherein the UV blocking layer comprises metal-oxide nano-particles. 
     
     
         6 . The structure of  claim 4 , wherein the metal oxide nano-particles comprise one or more of MoO 3 , MnO 2 , NiO, WO 3 , and AlZnO. 
     
     
         7 . The structure of  claim 1 , wherein a material of the UV blocking layer has an energy gap with an absorption edge between 3.0 and 3.18 eV. 
     
     
         8 . A display, comprising:
 a substrate having driving circuitry;   a plurality of light-emitting diodes structures disposed on a substrate, each light emitting diode structure including
 a light-emitting diode including an emissive electroluminescent layer situated between two electrodes, 
 a light extraction layer (LEL) comprising a UV-cured ink, and 
 a UV blocking layer between the LEL and the light-emitting diode, the UV blocking layer having a thickness of 50-500 nm and at least 90% absorption to UV light of wavelengths for curing the UV-cured ink; and 
   a plurality of plateaus that separate light extraction layers of adjacent light-emitting diodes structures.   
     
     
         9 . The display of  claim 8 , wherein the LEL layer has a thickness of up to 5 μm. 
     
     
         10 . The display of  claim 8 , wherein the UV blocking layer comprises organic charge transport molecules. 
     
     
         11 . The display of  claim 8 , wherein the UV blocking layer comprises metal-oxide nano-particles. 
     
     
         12 . The display of  claim 8 , wherein a top surface of the LEL projects above a top surface of the plateaus. 
     
     
         13 . The display of  claim 8 , wherein a top surface of the LEL is substantially coplanar with a top surface of the plateaus. 
     
     
         14 . A method for manufacturing a light-emitting diode (LED) structure, the method comprising:
 depositing a UV blocking layer over a light-emitting diode including an emissive electroluminescent layer situated between two electrodes;   depositing a layer of UV-curable fluid over the UV blocking layer; and   curing the layer of UV-curable fluid with UV light to form a light extraction layer (LEL) over the UV blocking layer,   wherein the UV blocking layer having a thickness of 50-500 nm and at least 90% absorption to UV light of wavelengths for curing UV-curable fluid.   
     
     
         15 . The method of  claim 14 , wherein depositing the layer of UV-curable fluid comprises ejecting droplets of the UV-curable fluid from a nozzle. 
     
     
         16 . The method of  claim 15 , wherein the droplets are ejected to at least partially fill a plurality of wells. 
     
     
         17 . The method of  claim 16 , wherein depositing the layer of UV-curable fluid comprises successively forming a plurality of sublayers in each well. 
     
     
         18 . The method of  claim 17 , wherein forming a sublayer of the plurality of sublayers comprises ejecting one or more droplets of the UV-curable fluid into the well and curing the fluid before forming a subsequent sublayer. 
     
     
         19 . The method of  claim 18 , wherein forming the sublayer in the well comprises depositing a single droplet of the UV-curable fluid into the well. 
     
     
         20 . The method of  claim 18 , wherein forming the sublayer comprises depositing multiple single droplets of the UV-curable fluid into the well. 
     
     
         21 . The method of  claim 14 , wherein the light extraction layer (LEL) has a thickness of up to 5 μm.