Light emitting element and azole compound
View Patent ↗A light emitting element comprising at least a light emitting layer containing a light emitting material and a host material and having a light emission maximum wavelength of 500 nm or less wherein the minimum excitation triplet energy level of the host material is higher than the minimum excitation triplet energy level of the light emitting material.
1. A light emitting element comprising at least a light emitting layer containing a light emitting material and a host material and having a peak emission maximum wavelength of 500 nm or less measured under a fixed d.c. voltage wherein the minimum excitation triplet energy level of said host material is higher than the minimum excitation triplet energy level of said light emitting material, and
wherein the peak emission maximum wavelength of 500 nm or less is derived from a transition from the minimum excitation triplet energy of at least one of the components of the light emitting layer to the ground state of said at least one of the components of the light emitting layer,
wherein the peak emission maximum wavelength is the maximum for at least one of the components of the light emitting layer, and wherein the minimum excitation triplet energy level of said host material is from 68 kcal/mol to 90 kcal/mol, and
wherein the light emitting material is an orthometallated iridium complex.
2. A light emitting element according to claim 1 , further comprising a layer which is disposed adjacent to said light emitting layer and contains an organic material, wherein the minimum excitation triplet energy level of said organic material is higher than the minimum excitation triplet energy level of each of materials which constitute said light emitting layer.
3. A light emitting element according to claim 2 , wherein the minimum excitation triplet energy level of said organic material contained in the layer which is disposed adjacent to the light emitting layer is from 1.05 times to 1.38 times the minimum excitation triplet energy level of each of the materials which constitute said light emitting layer.
4. A light emitting element according to claim 2 , wherein the minimum excitation triplet energy level of said organic material contained in the layer which is disposed adjacent to the light emitting layer is from 68 kcal/mol to 90 kcal/mol.
5. A light emitting element according to claim 2 , wherein said organic material contained in the layer which is disposed adjacent to said light emitting layer is a compound represented by the following formula (II):
L 2 -(Q 2 )n 2 Formula (II)
wherein L 2 represents a bivalent or more linking group; Q 2 represents an aromatic hydrocarbon ring or an aromatic hetero ring; and n 2 represents a number of 2 or more, plural Q 2 may be the same or may be different from each other.
6. A light emitting element according to claim 2 , wherein the layer adjacent to the light emitting layer is selected from the group consisting of a hole injecting layer, a hole transporting layer, an electron injecting layer, an electron transporting layer, a hole blocking layer, and an electron blocking layer.
7. A light emitting element according to claim 1 , wherein said host material is a compound represented by the following formula (I):
L 1 -(Q 1 )n 1 Formula (I)
wherein L 1 represents a bivalent or more linking group; Q 1 represents an aromatic hydrocarbon ring or an aromatic hetero ring; and n 1 represents a number of 2 or more, plural Q 1 may be the same or may be different from each other.
8. A light emitting element according to claim 1 , wherein the light emitting layer is held between a pair of electrodes.
9. A light emitting element according to claim 1 , wherein the peak emission maximum wavelength λmax is measured under a fixed d.c. voltage is from 390 to 495 nm.
10. The light emitting element according to claim 1 , wherein the light emitting layer comprises 0.1% by weight to 20% by weight of the light emitting material with respect to a weight of the host material.
11. A light emitting element according to claim 1 , wherein the light emitting layer has a thickness from 1 nm to 5 μm.
12. A light emitting element according to claim 1 , wherein the host material includes a structure selected from the group consisting of a carbazole, a diarylamine, a pyridine, a pyrazine, a triazine and an arylsilane.
13. A light emitting element according to claim 1 , wherein the light emitting layer comprising the host material doped with the light emitting material is formed by vapor codeposition.
14. A light emitting element according to claim 1 , wherein the light emitting layer is formed by a method selected from the group consisting of a resistance heating vapor deposition method, an electron beam method, a sputtering method, a molecular accumulation method, a coating method, an ink-jet method, a printing method and an LB method.
15. A light emitting element comprising at least a light emitting layer containing a light emitting material and a host material and having a peak emission maximum wavelength of 500 nm or less measured under a fixed d.c. voltage wherein the minimum excitation triplet energy level of said host material is higher than the minimum excitation triplet energy level of said light emitting material, and
wherein the peak emission maximum wavelength of 500 nm or less is derived from a transition from the minimum excitation triplet energy of at least one of the components of the light emitting layer to the ground state of said at least one of the components of the light emitting layer,
wherein the peak emission maximum wavelength is the maximum for at least one of the components of the light emitting layer, and wherein the minimum excitation triplet energy level of said host material is from 68 kcal/mol to 90 kcal/mol, and, wherein an external quantum efficiency of the light emitting element measured under a fixed d.c. voltage is 5% to about 20%.
16. A light emitting element according to claim 15 , further comprising a layer which is disposed adjacent to said light emitting layer and contains an organic material, wherein the minimum excitation triplet energy level of said organic material is higher than the minimum excitation triplet energy level of each of materials which constitute said light emitting layer.
17. A light emitting element according to claim 16 , wherein the minimum excitation triplet energy level of said organic material contained in the layer which is disposed adjacent to the light emitting layer is from 1.05 times to 1.38 times the minimum excitation triplet energy level of each of the materials which constitute said light emitting layer.
18. A light emitting element according to claim 16 , wherein the minimum excitation triplet energy level of said organic material contained in the layer which is disposed adjacent to the light emitting layer is from 68 kcal/mol to 90 kcal/mol.
19. A light emitting element according to claim 16 , wherein said organic material contained in the layer which is disposed adjacent to said light emitting layer is a compound represented by the following formula (II):
L 2 -(Q 2 )n 2 Formula (II)
wherein L 2 represents a bivalent or more linking group; Q 2 represents an aromatic hydrocarbon ring or an aromatic hetero ring; and n 2 represents a number of 2 or more, plural Q 2 may be the same or may be different from each other.
20. A light emitting element according to claim 15 , wherein said host material is a compound represented by the following formula (I):
L 1 -(Q 1 )n 1 Formula (I)
wherein L 1 represents a bivalent or more linking group; Q 1 represents an aromatic hydrocarbon ring or an aromatic hetero ring; and n 1 represents a number of 2 or more, plural Q 1 may be the same or may be different from each other.
21. A light emitting element according to claim 15 , wherein the light emitting layer is held between a pair of electrodes.
22. A light emitting element according to claim 15 , wherein the peak emission maximum wavelength λmax measured under a fixed d.c. voltage is from 390 to 495 nm.
23. A light emitting element comprising at least a light emitting layer containing a light emitting material and a host material and having a peak emission maximum wavelength of 500 nm or less measured under a fixed d.c. voltage wherein the minimum excitation triplet energy level of said host material is higher than the minimum excitation triplet energy level of said light emitting material, and
wherein the peak emission maximum wavelength of 500 nm or less is derived from a transition from the minimum excitation triplet energy of at least one of the components of the light emitting layer to the ground state of said at least one of the components of the light emitting layer,
wherein the peak emission maximum wavelength is the maximum for at least one of the components of the light emitting layer, and wherein the light emitting material is an orthometallated iridium complex.
24. A light emitting element according to claim 23 , further comprising a layer which is disposed adjacent to said light emitting layer and contains an organic material, wherein the minimum excitation triplet energy level of said organic material is higher than the minimum excitation triplet energy level of each of materials which constitute said light emitting layer.
25. A light emitting element according to claim 24 , wherein the minimum excitation triplet energy level of said organic material contained in the layer which is disposed adjacent to the light emitting layer is from 1.05 times to 1.38 times the minimum excitation triplet energy level of each of the materials which constitute said light emitting layer.
26. A light emitting element according to claim 24 , wherein the minimum excitation triplet energy level of said organic material contained in the layer which is disposed adjacent to the light emitting layer is from 68 kcal/mol to 90 kcal/mol.
27. A light emitting element according to claim 24 , wherein said organic material contained in the layer which is disposed adjacent to said light emitting layer is a compound represented by the following formula (II):
L 2 -(Q 2 )n 2 Formula (II)
wherein L 2 represents a bivalent or more linking group; Q 2 represents an aromatic hydrocarbon ring or an aromatic hetero ring; and n 2 represents a number of 2 or more, plural Q 2 may be the same or may be different from each other.
28. A light emitting element according to claim 24 , wherein the layer adjacent to the light emitting layer is selected from the group consisting of a hole injecting layer, a hole transporting layer, an electron injecting layer, an electron transporting layer, a hole blocking layer, and an electron blocking layer.
29. A light emitting element according to claim 23 , wherein said host material is a compound represented by the following formula (I):
L 1 -(Q 2 )n 1 Formula (I)
wherein L 1 represents a bivalent or more linking group; Q 1 represents an aromatic hydrocarbon ring or an aromatic hetero ring; and n 1 represents a number of 2 or more, plural Q 1 may be the same or may be different from each other.
30. A light emitting element according to claim 23 , wherein the light emitting layer is held between a pair of electrodes.
31. A light emitting element according to claim 23 , wherein the peak emission maximum wavelength λmax measured under a fixed d.c. voltage is from 390 to 495 nm.
32. A light emitting element according to claim 23 , wherein the light emitting layer comprises 0.1% by weight to 20% by weight of the light emitting material with respect to a weight of the host material.
33. A light emitting element according to claim 23 , wherein the light emitting layer has a thickness from 1 nm to 5 μm.
34. A light emitting element according to claim 23 , wherein the host material includes a structure selected from the group consisting of a carbazole, a diarylamine, a pyridine, a pyrazine, a triazine and an arylsilane.
35. A light emitting element according to claim 23 , wherein the light emitting layer comprising the host material doped with the light emitting material is formed by vapor codeposition.
36. A light emitting element according to claim 23 , wherein the light emitting layer is formed by a method selected from the group consisting of a resistance heating vapor deposition method, an electron beam method, a sputtering method, a molecular accumulation method, a coating method, an ink-jet method, a printing method and an LB method.
37. A light emitting element comprising at least a light emitting layer containing a light emitting material and a host material and having a peak emission maximum wavelength of 500 nm or less measured under a fixed d.c. voltage wherein the minimum excitation triplet energy level of said host material is higher than the minimum excitation triplet energy level of said light emitting material, and
wherein the peak emission maximum wavelength of 500 nm or less is derived from a transition from the minimum excitation triplet energy of at least one of the components of the light emitting layer to the ground state of said at least one of the components of the light emitting layer,
wherein the peak emission maximum wavelength is the maximum for at least one of the components of the light emitting layer, and wherein the light emitting material is selected from the group consisting of an iridium complex, an osmium complex, and a platinum complex,
wherein an external quantum efficiency of the light emitting element measured under a fixed d.c. voltage is 5% to about 20%.
38. A light emitting element according to claim 37 , further comprising a layer which is disposed adjacent to said light emitting layer and contains an organic material, wherein the minimum excitation triplet energy level of said organic material is higher than the minimum excitation triplet energy level of each of materials which constitute said light emitting layer.
39. A light emitting element according to claim 38 , wherein the minimum excitation triplet energy level of said organic material contained in the layer which is disposed adjacent to the light emitting layer is from 1.05 times to 1.38 times the minimum excitation triplet energy level of each of the materials which constitute said light emitting layer.
40. A light emitting element according to claim 38 , wherein the minimum excitation triplet energy level of said organic material contained in the layer which is disposed adjacent to the light emitting layer is from 68 kcal/mol to 90 kcal/mol.
41. A light emitting element according to claim 38 , wherein said organic material contained in the layer which is disposed adjacent to said light emitting layer is a compound represented by the following formula (II):
L 2 -(Q 2 )n 2 Formula (II)
wherein L 2 represents a bivalent or more linking group; Q 2 represents an aromatic hydrocarbon ring or an aromatic hetero ring; and n 2 represents a number of 2 or more, plural Q 2 may be the same or may be different from each other.
42. A light emitting element according to claim 38 , wherein the layer adjacent to the light emitting layer is selected from the group consisting of a hole injecting layer, a hole transporting layer, an electron injecting layer, an electron transporting layer, a hole blocking layer, and an electron blocking layer.
43. A light emitting element according to claim 36 , wherein said host material is a compound represented by the following formula (I):
L 1 -(Q 2 )n 1 Formula (I)
wherein L 1 represents a bivalent or more linking group; Q 1 represents an aromatic hydrocarbon ring or an aromatic hetero ring; and n 1 represents a number of 2 or more, plural Q 1 may be the same or may be different from each other.
44. A light emitting element according to claim 37 , wherein the light emitting layer is held between a pair of electrodes.
45. A light emitting element according to claim 37 , wherein the peak emission maximum wavelength λmax measured under a fixed d.c. voltage is from 390 to 495 nm.
46. The light emitting element according to claim 37 , wherein the light emitting layer comprises 0.1% by weight to 20% by weight of the light emitting material with respect to a weight of the host material.
47. A light emitting element according to claim 37 , wherein the light emitting layer has a thickness from 1 nm to 5 μm.
48. A light emitting element according to claim 37 , wherein the light emitting material is an orthometallated iridium complex.
49. A light emitting element according to claim 37 , wherein the host material includes a structure selected from the group consisting of a carbazole, a diarylamine, a pyridine, a pyrazine, a triazine and an arylsilane.
50. A light emitting element according to claim 37 , wherein the light emitting layer comprising the host material doped with the light emitting material is formed by vapor codeposition.
51. A light emitting element according to claim 37 , wherein the light emitting layer is formed by a method selected from the group consisting of a resistance heating vapor deposition method, an electron beam method, a sputtering method, a molecular accumulation method, a coating method, an ink-jet method, a printing method and an LB method.
52. A light emitting element according to claim 37 , wherein the minimum excitation triplet energy level of said host material is from 68 kcal/mol to 90 kcal/mol.