Blue organic EL element, organic EL display panel, and manufacturing method of blue organic EL element
View Patent ↗An organic electroluminescence (EL) element emitting blue light from a light emitting surface and including: a first electrode; an organic light-emitting layer disposed on the first electrode and/or closer to the light emitting surface than the first electrode; and a second electrode disposed on the organic light-emitting layer and/or closer to the light emitting surface than the organic light-emitting layer. In the organic EL element emitting blue light, the organic light-emitting layer contains an organic light-emitting material emitting, through photoluminescence, blue light that has a CIE y coordinate no greater than 0.13 such that a luminance drop due to film shape is suppressed to 10% or smaller.
1. An organic electroluminescence (EL) element emitting blue light from a light emitting surface and comprising:
a first electrode;
an organic light-emitting layer disposed on the first electrode and/or closer to the light emitting surface than the first electrode; and
a second electrode disposed on the organic light-emitting layer and/or closer to the light emitting surface than the organic light-emitting layer, wherein
the organic light-emitting layer contains an organic light-emitting material emitting, through photoluminescence, blue light that has a CIE y coordinate no greater than 0.13 such that a luminance drop due to film shape is suppressed to 10% or smaller.
2. The organic EL element of claim 1 , wherein
at least a part of the organic light-emitting layer acts as a light-emitting portion, and
a difference between a maximum and a minimum thickness of the organic light-emitting layer within the light-emitting portion is no smaller than 10% of an average thickness of the organic light-emitting layer within the light-emitting portion.
3. The organic EL element of claim 2 , wherein
in at least one cross-section of the organic EL element, a planar portion of the light-emitting portion occupies no more than two thirds of a length of the organic light-emitting layer.
4. The organic EL element of claim 3 , wherein
the organic light-emitting layer has a concave top surface.
5. The organic EL element of claim 1 , wherein
at least one of the first electrode and the second electrode has optical reflectivity.
6. The organic EL element of claim 5 , wherein
the first electrode and the second electrode, together, form an optical microresonator that amplifies blue light.
7. The organic EL element of claim 1 , wherein
the organic light-emitting material emits, through photoluminescence, blue light that has a CIE y coordinate no smaller than 0.05.
8. The organic EL element of claim 1 , wherein
at least at a part of the organic light-emitting layer, a thickness of the organic light-emitting layer decreases when approaching a center portion of the organic light-emitting layer from an outer portion of the organic light-emitting layer.
9. An organic EL display panel comprising:
a substrate;
a bank layer disposed on the substrate and/or closer to a light emitting surface than the substrate, the bank layer defining opening areas; and
a plurality of organic EL elements, the plurality of organic EL elements each including an organic light-emitting layer disposed in a respective one of the opening areas, wherein
the plurality of organic EL elements include at least one organic EL element emitting blue light, and
an organic light-emitting layer of the at least one organic EL element emitting blue light contains an organic light-emitting material emitting, through photoluminescence, blue light that has a CIE y coordinate no greater than 0.13 such that a luminance drop due to film shape is suppressed to 10% or smaller.
10. The organic EL display panel of claim 9 , wherein
the plurality of organic EL elements include a plurality of organic EL elements emitting blue light,
the plurality of organic EL elements form rows and columns along a top surface of the substrate forming a matrix, and
the matrix includes at least one column composed of only the plurality of organic EL elements emitting blue light.
11. The organic EL display panel of claim 10 , wherein
at least a part of the organic light-emitting layer acts as a light-emitting portion,
a difference between a maximum and a minimum thickness of the organic light-emitting layer at the light-emitting portion is no smaller than 10% of an average thickness of the organic light-emitting layer within the light-emitting portion, and
in a transverse cross-section of each column in the matrix, a planar portion of the light-emitting portion occupies no more than two thirds of a length of the organic light-emitting layer.
12. The organic EL display panel of claim 10 , wherein
the opening areas extend along the columns in the matrix forming an extended opening area, and
in each of the opening areas, a respective organic light-emitting layer of a respective organic EL element disposed in the respective opening area is continuous with organic light-emitting layers of each of remaining organic EL elements disposed in the extended opening area.
13. A manufacturing method of an organic EL element emitting blue light and including a first electrode, an organic light-emitting layer, and a second electrode that are layered in a stated order, the manufacturing method comprising:
forming the organic light-emitting layer through application and drying of an ink containing an organic light-emitting material, the organic light-emitting material emitting, through photoluminescence, blue light that has a CIE y coordinate no greater than 0.13 such that a luminance drop due to film shape is suppressed to 10% or smaller.