Organic electroluminescent display device and method for producing same

Abstract

This organic EL display device ( 100 ) is provided with an element substrate which comprises multiple pixels and which comprises organic EL elements ( 3 ) arranged in each pixel and bank layers ( 48 ) defining the pixels, and a thin-film sealing structure ( 10 ) which covers the pixels. The thin-film sealing structure includes a first inorganic barrier layer ( 12 ), and an organic barrier layer ( 14 ) in contact with the upper surface or lower surface of the first inorganic barrier layer. The multiple pixels include red pixels, green pixels and blue pixels, and further have a polydiacetylene layer ( 52 ) which exhibits a blue color and which is provided selectively on a second inorganic barrier layer ( 16 ) of the thin-film sealing structure on blue pixels. The polydiacetylene layer is a polymer of 10,12-pentacosadiynoic acid.

1 . An organic electroluminescent display device including a plurality of pixels, the organic electroluminescent display device comprising:
 an element substrate including a substrate, a plurality of organic electroluminescent elements supported by the substrate and respectively located in the plurality of pixels, and a bank layer defining the plurality of pixels; and   a thin film encapsulation structure covering the plurality of pixels,   wherein each of the plurality of organic electroluminescent elements has a microcavity structure,   wherein the thin film encapsulation structure includes a first inorganic barrier layer and an organic barrier layer in contact with a top surface or a bottom surface of the first inorganic barrier layer,   wherein the plurality of pixels include a red pixel having an organic electroluminescent element that emits only red light, a green pixel having an organic electroluminescent element that emits only green light, and a blue pixel having an organic electroluminescent element that emits only blue light,   a thickness of an organic electroluminescent layer included in the blue pixel is smaller than a thickness of an organic electroluminescent layer included in the red pixel and a thickness of an organic electroluminescent layer included in the green pixel,   wherein the organic electroluminescent display device further includes a polydiacetylene layer selectively provided only on the thin film encapsulation structure on the blue pixel, which exhibits blue color and further narrows a spectral width of the blue light, and no polydiacetylene layer on the thin film encapsulation structure on the organic electroluminescent element that emits only the red light and the thin film encapsulation structure on the organic electroluminescent element that emits only the green light, and   wherein the polydiacetylene layer is formed of a polymer of 10,12-pentacosadiynoic acid.   
     
     
         2 . The organic electroluminescent display device of  claim 1 ,
 wherein the organic barrier layer included in the thin film encapsulation structure is in contact with the top surface of the first inorganic barrier layer and includes a plurality of solid portions distributed discretely,   wherein the thin film encapsulation structure further includes a second inorganic barrier layer in contact with the top surface of the first inorganic barrier layer and top surfaces of the plurality of solid portions of the organic barrier layer, and   the polydiacetylene layer is formed on the second inorganic barrier layer.   
     
     
         3 . The organic electroluminescent display device of  claim 1 , wherein the polydiacetylene layer is semiconductive. 
     
     
         4 . The organic electroluminescent display device of  claim 3 , wherein the polydiacetylene layer has a specific resistance smaller than, or equal to, 1×10 −1  Ωcm. 
     
     
         5 . The organic electroluminescent display device of  claim 1 , further comprising an ultraviolet absorbing layer located on the polydiacetylene layer. 
     
     
         6 . The organic electroluminescent display device of  claim 1 , wherein the first inorganic barrier layer is formed of silicon nitride. 
     
     
         7 . The organic electroluminescent display device of  claim 1 , wherein the polydiacetylene layer has a thickness of 0.5 μm or greater and 2.0 μm or less. 
     
     
         8 . The organic electroluminescent display device of  claim 1 , wherein the polydiacetylene layer provides a transmission spectrum of blue light in which the blue light has a peak wavelength in the range of 460 nm or longer and 470 nm or shorter. 
     
     
         9 . The organic electroluminescent display device of  claim 8 , wherein the polydiacetylene layer has a transmittance for the blue light higher than, or equal to, 80% at the peak wavelength thereof. 
     
     
         10 . A method for producing an organic electroluminescent display device including a plurality of pixels, the organic electroluminescent display device comprising:
 an element substrate including a substrate, a plurality of organic electroluminescent elements supported by the substrate and respectively located in the plurality of pixels, and a bank layer defining the plurality of pixels; and   a thin film encapsulation structure covering the plurality of pixels, wherein:   the thin film encapsulation structure includes a first inorganic barrier layer and an organic barrier layer in contact with a top surface or a bottom surface of the first inorganic barrier layer;   the plurality of pixels include a red pixel having an electroluminescent element that emits only red light, a green pixel having an electroluminescent element that emits only green light, and a blue pixel having an electroluminescent element that emits only blue light;   the organic electroluminescent display device further includes a polydiacetylene layer selectively provided only on the thin film encapsulation structure on the blue pixel and exhibiting a blue color, and   the polydiacetylene layer is a polymer of 10,12-pentacosadiynoic acid;   forming the polydiacetylene layer comprises:   after the thin film encapsulation structure is formed, depositing 10,12-pentacosadiynoic acid on the thin film encapsulation structure by mask vapor deposition; and   irradiating the 10,12-pentacosadiynoic acid with an electron beam or ultraviolet rays.   
     
     
         11 . The method of  claim 10 , wherein forming the thin film encapsulation structure comprises:
 forming a silicon nitride layer; and   after the silicon nitride layer is formed, depositing the 10,12-pentacosadiynoic acid by the mask vapor deposition without exposing the silicon nitride layer to the atmosphere.   
     
     
         12 . The method of  claim 10 , wherein:
 the organic barrier layer included in the thin film encapsulation structure is in contact with the top surface of the first inorganic barrier layer and includes a plurality of solid portions distributed discretely;   the thin film encapsulation structure further includes a second inorganic barrier layer in contact with the top surface of the first inorganic barrier layer and top surfaces of the plurality of solid portions of the organic barrier layer; and   the polydiacetylene layer is formed on the second inorganic barrier layer.   
     
     
         13 . The method of  claim 10 , wherein the polydiacetylene layer is semiconductive. 
     
     
         14 . The method of  claim 13 , wherein the polydiacetylene layer has a specific resistance smaller than, or equal to, 1×10 −1  Ωcm. 
     
     
         15 . The method of  claim 14 , wherein the organic electroluminescent display device further comprises an ultraviolet absorbing layer located on the polydiacetylene layer. 
     
     
         16 . The method of  claim 10 , wherein the first inorganic barrier layer is formed of silicon nitride. 
     
     
         17 . The method of  claim 10 , wherein the polydiacetylene layer has a thickness of 0.5 μm or greater and 2.0 μm or less. 
     
     
         18 . The method of  claim 10 , wherein the polydiacetylene layer provides a transmission spectrum of blue light in which the blue light has a peak wavelength in the range of 460 nm or longer and 470 nm or shorter. 
     
     
         19 . The method of  claim 18 , wherein the polydiacetylene layer has a transmittance for the blue light higher than, or equal to, 80% at the peak wavelength thereof.