Organic el light-emitting element and manufacturing method thereof

Abstract

An organic EL light-emitting element is provided in which, by means of an organic material that is oligomeric, an organic layer coated film 25 is formed in a high-definition pixel pattern in the openings 23a of insulation banks 23 that are formed to be hydrophilic; a manufacturing method of said organic EL light-emitting element is also provided. The coated film 25 is formed by dropwise injection of a liquid composition containing an organic material oligomer.

1 . A top emission type organic electroluminescent light-emitting element comprising:
 a substrate,   a first electrode provided on a surface of the substrate,   an insulation bank formed to surround at least part of the first electrode,   one or more organic layers formed on the first electrode surrounded by the insulation bank, and   a second electrode having translucency formed on the one or more organic layers,   wherein the insulation bank has a forward tapered shape or a sidewall of the insulation bank is formed such as to be substantially perpendicular to the first electrode, and a surface of the insulation bank is formed to have a hydrophilic property, and a contact angle of the surface of the insulation bank to water is 15° or more and 60° or less,   each of the one or more organic layers is a coated-type organic layer formed of an oligomer having a molecular weight of 300 or more and 5000 or less of an organic material, and the one or more organic layers comprise a light-emitting layer,   a thickness of the second electrode is 5 nm or more and 30 nm or less, and   light is taken out from a surface of the top emission type organic electroluminescent light-emitting element, the surface including the second electrode.   
     
     
         2 . The top emission type organic electroluminescent light-emitting element of  claim 1 , wherein the insulation bank has the forward tapered shape and an angle of the sidewall of the insulation bank to the first electrode is 10° or more and 80° or less. 
     
     
         3 . The top emission type organic electroluminescent light-emitting element of  claim 1 , wherein the surface of the insulation bank is a modified surface having an arithmetic average roughness of 5 nm or more and 30 nm or less. 
     
     
         4 . The top emission type organic electroluminescent light-emitting element of  claim 1 , wherein a pinning position of the one or more organic layers is provided in a position such that a height of the pinning position from a surface of the first electrode is greater than a height of a thinnest part of the one or more organic layers from a surface of the first electrode, the pinning position being a contact point between the one or more organic layers and the sidewall of the insulation bank. 
     
     
         5 . The top emission type organic electroluminescent light-emitting element of  claim 1 , wherein an area of the first electrode surrounded by the insulation bank is 100 μm2 or more and 850 μm2 or less. 
     
     
         6 . A method of manufacturing a top emission type organic electroluminescent light-emitting element comprising:
 forming a first electrode on a surface of a substrate,   forming an insulation bank to surround at least part of the first electrode,   forming one or more organic layers comprising a light-emitting layer on an area of the first electrode surrounded by the insulation bank, each of the one or more organic layers being formed of an oligomer having a molecular weight of 300 or more and 5000 or less of an organic material, and each of the one or more organic layers being formed as a coated-type organic layer, and   forming a second electrode having translucency on the one or more organic layers,   wherein the method comprises conducting a modifying treatment to a surface of a sidewall of an opening surrounded by the insulation bank so as to have a contact angle of the surface of the sidewall of the opening surrounded by the insulation bank to water of 15° or more and 60° or less before forming the one or more organic layers,   the second electrode is formed to have a thickness of 5 nm or more and 30 nm or less,   each of the one or more organic layers is formed by supplying a droplet with a volume per one drop of 0.05 pL or more and 1 pL or less of a liquid composition comprising the oligomer of the organic material for the one or more organic layers using an ink-jet process, and   the top emission type organic electroluminescent light-emitting element is formed such that light is taken out from a surface of the top emission type organic electroluminescent light-emitting element, the surface of the top emission type organic electroluminescent light-emitting element including the second electrode.   
     
     
         7 . The method of manufacturing a top emission type organic electroluminescent light-emitting element of  claim 6 , wherein the modifying treatment is conducted by modifying an arithmetic average roughness of a surface of the insulation bank through a rehardening of the surface of the insulation bank or an exposure to a dissolving solvent. 
     
     
         8 . The method of manufacturing a top emission type organic electroluminescent light-emitting element of  claim 6 , wherein the modifying treatment is conducted by introducing a polar functional group onto a surface of the insulation bank by a plasma irradiation, a UV irradiation, or an ozone treatment. 
     
     
         9 . The method of manufacturing a top emission type organic electroluminescent light-emitting element of  claim 6 , wherein the insulation bank is formed such that the area of the first electrode surrounded by the insulation bank is 100 μm2 or more and 850 μm2 or less.