Organic EL element and organic EL display
The organic EL element of the invention includes an organic thin layer which includes at least a light-emitting layer, between a positive electrode and a negative electrode, wherein a layer in the organic thin layer includes a 1,3,6,8-tetraphenylpyrene compound expressed by the following structural formula (1) and a triphenylbenzene derivative expressed by the following structural formula (2). Preferably, the triphenylbenzene derivative is 1,3,5-tris[4-(N-carbazolyl)phenyl]benzene (TCPB). In the structural formula (1), R 1 to R 4 represent one of a hydrogen atom, alkyl group, cycloalkyl group, and aryl group. In the structural formula (2), R 5 represents a carbazole skeleton expressed by the following structural formula (3). In the structural formula (3), R 6 and R 7 represent a hydrogen atom, or a substituent group.
1 . An organic EL element comprising:
a positive electrode;
a negative electrode; and
an organic thin layer between the positive electrode and the negative electrode,
wherein the organic thin layer comprises a light-emitting layer,
wherein a layer in the organic thin layer comprises a 1,3,6,8-tetraphenylpyrene compound expressed by the following structural formula (1) and a triphenylbenzene derivative expressed by the following structural formula (2):
where, in the structural formula (1), R 1 to R 4 may be identical or different each other, and represent a hydrogen atom, or at least one of an alkyl group, cycloalkyl group, and aryl group, which may have a substituent group;
where, in the structural formula (2), R 5 represents a carbazole skeleton expressed by the following structural formula (3):
where, in the structural formula (3), R 6 and R 7 may be identical or different each other, and represent a hydrogen atom, or a substituent group.
2 . The organic EL element according to claim 1 , wherein the 1,3,6,8-tetraphenylpyrene compound expressed by the structural formula (1) is a 1,3,6,8-tetra(4-biphenyl)pyrene compound expressed by the following structural formula (4):
where, in the structural formula (4), R 8 to R 11 may be identical or different each other, and represent a hydrogen atom, or at least one of an alkyl group, cycloalkyl group, and aryl group, which may have a substituent group.
3 . The organic EL element according to claim 1 , wherein the triphenylbenzene derivative expressed by the structural formula (2) is 1,3,5-tris[4-(N-carbazolyl)phenyl]benzene (TCPB) expressed by the following structural formula (5):
4 . The organic EL element according to claim 1 , wherein a content of the 1,3,6,8-tetraphenylpyrene compound in the layer which comprises the 1,3,6,8-tetraphenylpyrene compound expressed by the structural formula (1) is 1% by mass to 20% by mass.
5 . The organic EL element according to claim 2 , wherein a content of the 1,3,6,8-tetra(4-biphenyl)pyrene compound in the layer which comprises the 1,3,6,8-tetra(4-biphenyl)pyrene compound expressed by the structural formula (4) is 5% by mass to 12% by mass.
6 . The organic EL element according to claim 5 , wherein a content of the 1,3,6,8-tetra(4-biphenyl)pyrene compound in the layer which comprises the 1,3,6,8-tetra(4-biphenyl)pyrene compound expressed by the structural formula (4) is 6% by mass to 10% by mass.
7 . The organic EL element according to claim 4 , further comprising a hole-blocking layer between the layer which comprises the 1,3,6,8-tetraphenylpyrene compound expressed by the structural formula (1) and the negative electrode.
8 . The organic EL element according to claim 7 , wherein the hole-blocking layer comprises 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (bathocuproine; BCP) expressed by the following structural formula (6):
9 . The organic EL element according to claim 5 , further comprising a hole-blocking layer between the layer which comprises the 1,3,6,8-tetra(4-biphenyl)pyrene compound expressed by the structural formula (4) and the negative electrode.
10 . The organic EL element according to claim 9 , wherein the hole-blocking layer comprises BAlq expressed by the following structural formula (10):
11 . The organic EL element according to claim 1 , wherein the light-emitting layer has a thickness of 5 nm to 50 nm.
12 . The organic EL element according to claim 1 , which is used for emitting blue light.
13 . An organic EL display comprising an organic EL element,
wherein the organic EL element comprises:
a positive electrode;
a negative electrode; and
an organic thin layer between the positive electrode and the negative electrode,
wherein the organic thin layer comprises a light-emitting layer,
wherein a layer in the organic thin layer comprises a 1,3,6,8-tetraphenylpyrene compound expressed by the following structural formula (1) and a triphenylbenzene derivative expressed by the following structural formula (2):
where, in the structural formula (1), R 1 to R 4 may be identical or different each other, and represent a hydrogen atom, or at least one of an alkyl group, cycloalkyl group, and aryl group, which may have a substituent group;
where, in the structural formula (2), R 5 represents a carbazole skeleton expressed by the following structural formula (3):
where, in the structural formula (3), R 6 and R 7 may be identical or different each other, and represent a hydrogen atom, or a substituent group.
14 . The organic EL display according to claim 13 , wherein the organic EL display is one of a passive-matrix panel and an active-matrix panel.
15 . The organic EL display according to claim 13 , comprising an organic EL element for emitting blue light, an organic EL element for emitting green light, and an organic EL element for emitting red light,
wherein the organic EL element for emitting blue light, the organic EL element for emitting green light, and the organic EL element for emitting red light each comprise at least one of a hole-injecting layer and a hole-transporting layer which are shared with other organic EL elements,
wherein the organic EL element for emitting blue light comprises:
a positive electrode;
a negative electrode; and
an organic thin layer between the positive electrode and the negative electrode,
wherein the organic thin layer comprises a light-emitting layer,
wherein a layer in the organic thin layer comprises a 1,3,6,8-tetraphenylpyrene compound expressed by the following structural formula (1) and a triphenylbenzene derivative expressed by the following structural formula (2):
where, in the structural formula (1), R 1 to R 4 may be identical or different each other, and represent a hydrogen atom, or at least one of an alkyl group, cycloalkyl group, and aryl group, which may have a substituent group;
where, in the structural formula (2), R 5 represents a carbazole skeleton expressed by the following structural formula (3):
where, in the structural formula (3), R 6 and R 7 may be identical or different each other, and represent a hydrogen atom, or a substituent group.