Light-emitting device and image display apparatus including the same

Abstract

It is an object of the present invention to provide an image display apparatus capable of inhibiting or preventing the deterioration of a light conversion layer while high luminous efficiency and high color reproducibility are achieved. The present invention provides a light-emitting device including a pair of electrodes, an electroluminescent layer disposed between a first electrode and a second electrode, a light conversion layer including multiple pixels and converting light that is emitted from the electroluminescent layer and that has a blue emission spectrum into light having a different wavelength. The light conversion layer includes pixels of three primary colors of red (R), green (G), and blue (B) and contains a light-emitting nanocrystal having an emission spectrum in any of red (R), green (G), and blue (B) when light from the electroluminescent layer is incident on at least one of the three primary colors.

1 . A light-emitting device, comprising:
 a pair of electrodes including a first electrode and a second electrode disposed opposite each other;   an electroluminescent layer disposed between the first electrode and the second electrode; and   a light conversion layer including multiple pixels and converting light that is emitted from the electroluminescent layer and that has a blue emission spectrum into light having a different wavelength,   wherein the light conversion layer includes pixels of three primary colors of red (R), green (G), and blue (B), a scattering agent and contains a light-emitting nanocrystal having an emission spectrum in any of red (R), green (G), and blue (B) when light from the electroluminescent layer is incident on at least one of the three primary colors,   the scattering agent is selected from the group consisting of alumina, silica, titanium oxide, zeolite and zirconia.   
     
     
         2 . The light-emitting device according to  claim 1 , wherein the electroluminescent layer contains one or two or more light-emitting materials selected from the group consisting of an inorganic light-emitting material, a low-molecular-weight fluorescent material, an organic polymer fluorescent material, a phosphorescent material, and a thermally activated delayed fluorescent material. 
     
     
         3 . The light-emitting device according to  claim 2 , wherein the low-molecular-weight fluorescent material is a compound having at least one selected from the group consisting of an anthracene moiety, a tetracene moiety, a chrysene moiety, a phenanthrene moiety, a pyrene moiety, a perylene moiety, a stilbene moiety, an acridone moiety, a coumarin moiety, a phenoxazine moiety, and a phenothiazine moiety. 
     
     
         4 . The light-emitting device according to  claim 2 , wherein the phosphorescent material is a metal complex containing at least one metal atom selected from the group consisting of iridium, rhodium, platinum, ruthenium, osmium, scandium, yttrium, gadolinium, palladium, silver, gold, and aluminum. 
     
     
         5 . The light-emitting device according to  claim 2 , wherein the light-emitting material contains one or two or more host materials each having a larger energy gap than the light-emitting material. 
     
     
         6 . The light-emitting device according to  claim 2 , wherein the light that is emitted from the electroluminescent layer and that has the blue emission spectrum has a peak at 420 nm to 480 nm. Blue light: 380 to 500 nm (mid: 440 nm) 
     
     
         7 . The light-emitting device according to  claim 1 , wherein in the light conversion layer, an emission spectrum of at least one of red (R), green (G), and blue (B) has a full width at half maximum of 20 to 50 nm. 
     
     
         8 . The light-emitting device according to  claim 1 , wherein in the light conversion layer, the light-emitting nanocrystal includes a core containing at least one or two or more first semiconductor materials, and
 a shell covering the core and containing a second semiconductor material identical to or different from that of the core.   
     
     
         9 . The light-emitting device according to  claim 8 , wherein the first semiconductor material is one or two or more selected from the group consisting of II-VI group semiconductors, III-V group semiconductors, I-III-VI group semiconductors, group IV semiconductors, and I-II-IV-VI group semiconductors. 
     
     
         10 . An image display apparatus characterized by having a light emitting device according to  claim 1 , comprising a transistor layer electrically connected to the first electrode or the second electrode, wherein the light emitted from the electroluminescent layer is displayed through the light conversion layer and the transistor layer. 
     
     
         11 . An image display apparatus characterized by having a light emitting device according to  claim 1 , comprising a transistor layer electrically connected to the first electrode or the second electrode, wherein the light emitted from the electroluminescent layer is displayed without passing through the transistor layer.