Inkjet printing systems and techniques for light-emitting devices with enhanced light outcoupling

Abstract

The present teachings relate to various embodiments of ink compositions, which once printed and cured on a substrate form a continuous composite film layer that includes a first pattern of polymeric areas having a first refractive index (RI) interspersed within a second pattern of polymeric areas having an RI that is higher in comparison to the RI of the first pattern of polymeric areas. Various embodiments of composite thin films so formed on a substrate can be tuned so as to enhance light outcoupling or extraction for various light-emitting devices of the present teachings, such as, but not limited by, an OLED display or lighting device.

What is claimed is: 
     
         1 . A method of forming a film on a substrate, the method comprising:
 forming a composite polymeric film on the substrate by:
 depositing a first ink on the substrate in a first-defined pattern; 
 depositing a second ink on the substrate in a second-defined pattern; and 
 drying or curing the first ink to form a first pattern of polymeric areas; 
 drying or curing the second ink to form a second pattern of polymeric areas; and 
   depositing at least one thin film layer over the composite polymeric film, wherein the first pattern of polymeric areas has a refractive index that is closer to the refractive index of the substrate than to the refractive index of the at least one thin film, and further wherein the second pattern of polymeric areas has a refractive index that is closer to the refractive index of the at least one thin film layer than to the refractive index of the substrate.   
     
     
         2 . The method of  claim 1 , wherein the refractive index of the substrate is in the range from 1.45 to 1.5. 
     
     
         3 . The method of  claim 2 , wherein the refractive index of the first pattern of polymeric areas is in the range from 1.45 to 1.5. 
     
     
         4 . The method of  claim 1 , wherein the refractive index of the at least one thin film is in the range from 1.6 to 1.9. 
     
     
         5 . The method of  claim 4 , wherein the refractive index of the second pattern of polymeric areas is in the range from 1.6 to 1.9. 
     
     
         6 . The method of  claim 1 , wherein the first ink comprises an acrylate monomer, a methacrylate monomer, or combinations thereof. 
     
     
         7 . The method of  claim 6 , wherein the second ink comprises an acrylate monomer, a methacrylate monomer, or combinations thereof, and nanoparticles. 
     
     
         8 . The method of  claim 1 , wherein the first ink is dried or cured prior to depositing the second ink. 
     
     
         9 . The method of  claim 1 , wherein the first ink and the second ink are deposited before either of the first ink and the second ink is dried and cured. 
     
     
         10 . The method of  claim 1 , wherein the substrate is a substrate of an optoelectronic device and the at least one thin film is an electrode. 
     
     
         11 . The method of  claim 10 , wherein the electronic device is an organic light emitting diode. 
     
     
         12 . An optoelectronic device comprising:
 an optoelectronic device substrate;   a composite polymeric film on the optoelectronic device substrate, the composite polymeric film comprising a first pattern of polymeric areas and a second pattern of polymeric areas; and   at least one thin film layer over the composite polymeric film, wherein the first pattern of polymeric areas has a refractive index that is closer to the refractive index of the optoelectronic device substrate than to the refractive index of the at least one thin film, and further wherein the second pattern of polymeric areas has a refractive index that is closer to the refractive index of the at least one thin film layer than to the refractive index of the optoelectronic device substrate.   
     
     
         13 . The device of  claim 12 , wherein the refractive index of the substrate is in the range from 1.45 to 1.5. 
     
     
         14 . The device of  claim 13 , wherein the refractive index of the first pattern of polymeric areas is in the range from 1.45 to 1.5. 
     
     
         15 . The device of  claim 12 , wherein the refractive index of the at least one thin film is in the range from 1.6 to 1.9. 
     
     
         16 . The device of  claim 15 , wherein the refractive index of the second pattern of polymeric areas is in the range from 1.6 to 1.9. 
     
     
         17 . The device of  claim 12 , wherein the first pattern of polymeric areas comprises a polymerization product of an acrylate monomer, a methacrylate monomer, or combinations thereof. 
     
     
         18 . The device of  claim 17 , wherein the second pattern of polymeric areas comprises the polymerization product of an acrylate monomer, a methacrylate monomer, or combinations thereof, and nanoparticles. 
     
     
         19 . The device of  claim 12 , wherein the at least one thin film is an electrode. 
     
     
         20 . The device of  claim 19 , wherein the optoelectronic device is an organic light emitting diode.