Organic EL emitting layer having specific concentration profile
View Patent ↗An organic EL element includes a pair of electrodes and an emitting layer interposed therebetween. The emitting layer is made of a mixture containing a host material and a dopant material. In the emitting layer, a concentration profile of the dopant material along a thickness direction includes at least two relative maximums or at least two relative minimums.
1. An organic EL element comprising:
first and second electrodes and an emitting layer interposed therebetween,
the emitting layer being made of a mixture containing a host material and a dopant material, the dopant material being an organic material different from an organometallic compound, and
a concentration profile of the dopant material along a thickness direction in the emitting layer including at least two relative maximums or at least two relative minimums.
2. The element according to claim 1 , wherein the concentration profile includes at least two relative maximums.
3. The element according to claim 1 , wherein the concentration profile includes at least two relative minimums.
4. An organic EL display comprising pixels, each of the pixels including the organic EL element according to claim 1 .
5. The display according to claim 4 , wherein the concentration profile includes at least two relative maximums.
6. The display according to claim 4 , wherein the concentration profile includes at least two relative minimums.
7. The element according to claim 1 , further comprising:
a substrate;
a thin-film transistor located above the substrate; and
an insulating layer located above the thin-film transistor and including a through-hole, the first electrode being electrically connected to the thin-film transistor through the through-hole.
8. An organic EL element comprising:
first and second electrodes and an emitting layer interposed therebetween,
the emitting layer being made of a mixture containing a host material and a dopant material,
the dopant material being selected from the group consisting of dicyanomethylenepyrans, dicyanos, phenoxazones, thioxantens, rubrenes, stylyls, coumarins, quinacridones, and condensed aromatics, and
a concentration profile of the dopant material along a thickness direction in the emitting layer including at least two relative maximums or at least two relative minimums.
9. The element according to claim 8 , wherein the dopant material is selected from the group consisting of coumarin, rubrene, perylene, azathioxanten, N-methylquinacridone, diphenylnaphtacene, and perfianten.
10. The element according to claim 8 , wherein the concentration profile includes at least two relative maximums.
11. The element according to claim 8 , wherein the concentration profile includes at least two relative minimums.
12. The element according to claim 8 , further comprising:
a substrate;
a thin-film transistor located above the substrate; and
an insulating layer located above the thin-film transistor and including a through-hole, the first electrode being electrically connected to the thin-film transistor through the through-hole.
13. An organic EL display comprising pixels, each of the pixels including the organic EL element according to claim 8 .
14. The display according to claim 13 , wherein the dopant material is selected from the group consisting of coumarin, rubrene, perylene, azathioxanten, N-methylquinacridone, diphenylnaphtacene, and perflanten.
15. The display according to claim 13 , wherein the concentration profile includes at least two relative maximums.
16. The display according to claim 13 , wherein the concentration profile includes at least two relative minimums.