Red phosphorescent compound and organic electroluminescent device using the same

Abstract

Disclosed herein is a red phosphorescent compound represented by Formula 1 below:

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings:

FIG. 1 shows a graph showing a phenomenon wherein the color purity of an organic EL device becomes higher (i.e. as the x-values on CIE chromaticity coordinates increase), the relative spectral sensitivity of the organic EL device decreases; and

FIG. 2 shows the structural formulas of NPB, copper (II) phthalocyanine (CuPc), (btp)₂Ir(acac), Alq₃, BAlq, and CBP used in one embodiment of the red phosphorescent compound according to the present invention.

Claims

1. A red phosphorescent compound represented by Formula 1 below:

2. The red phosphorescent compound according to claim 1, wherein the red phosphorescent compound is a compound as follows:

3. An organic electroluminescent (EL) device comprising a light-emitting layer wherein a red phosphorescent compound of Formula 1 is used as a dopant for the light-emitting layer, wherein the red phosphorescent compound of Formula 1 is as follows:

4. The organic electroluminescent (EL) device according to claim 3, further comprising a sequential laminate of an anode, a hole injecting layer, a hole transport layer, an electron transport layer, an electron injecting layer, and a cathode, with the light-emitting layer interposed between the electron transport layer and the electron injecting layer.

5. The organic electroluminescent (EL) device according to claim 3, wherein the light-emitting layer uses one host selected from an Al complex, a Zn complex, and a carbazole derivative.

6. The organic electroluminescent (EL) device according to claim 5, wherein the Al or Zn complex has at least one ligand selected from the group consisting of quinol, biphenyl, isoquinol, phenyl, methylquinol, dimethylquinol and dimethylisoquinol.

7. The organic electroluminescent (EL) device according to claim 5, wherein the carbazole derivative is 4,4′-N,N′ dicarbazole biphenyl (CBP).

8. The organic electroluminescent (EL) device according to claim 3, wherein the dopant is used in an amount of 0.5 to 20% by weight.

9. The organic electroluminescent (EL) device according to claim 3, wherein the compound is a compound as follows:

10. An organic electroluminescent (EL) device comprising a first electrode, a light-emitting layer using a red phosphorescent compound as a dopant, and a second electrode, and exhibiting a luminescence of 1,300 to 1,450 cd/m2 and an electric current density of 8 to 10 mA/cm2 at an applied voltage of 5.7 to 6.1 V.

11. The organic electroluminescent (EL) device according to claim 10, wherein the device has a lifetime of 3,500 to 4,500 hours, wherein the lifetime is defined as the time taken before the luminance of the organic EL device decreases to half its initial value.

12. The organic electroluminescent (EL) device according to claim 10, wherein the device has a current efficiency of 10 to 15 cd/A.

13. The organic electroluminescent (EL) device according to claim 10, wherein the device has a power efficiency of 6 to 8 Im/W.

14. The organic electroluminescent (EL) device according to claim 10, wherein the dopant is a red phosphorescent compound represented by Formula 1 below:

15. The organic electroluminescent (EL) device according to claim 14, wherein the phosphorescent compound is a compound by represented below:

16. The organic electroluminescent (EL) device according to claim 10, wherein the light-emitting layer uses one host selected from an Al complex, a Zn complex, and a carbazole derivative.

17. The organic electroluminescent (EL) device according to claim 16, wherein the Al or Zn complex has at least one ligand selected from the group consisting of quinol, biphenyl, isoquinol, phenyl, methylquinol, dimethylquinol and dimethylisoquinol.

18. The organic electroluminescent (EL) device according to claim 16, wherein the carbazole derivative is 4,4′-N,N′ dicarbazole biphenyl (CBP).

19. The organic electroluminescent (EL) device according to claim 10, wherein the dopant is used in an amount of 0.5 to 20% by weight.