Efficient white organic light emitting diodes with high color quality

• US 9,331,299 B2
• Filed: 04/11/2014
• Issued: 05/03/2016
• Est. Priority Date: 04/11/2014
• Status: Active Grant

• Current Assignee: Universal Display Corporation
• Original Assignee: Universal Display Corporation
• Inventors: Xu, Xin, Weaver, Michael Stuart
• Primary Examiner(s): DIALLO, MAMADOU L
• Application Number:
  US14/250,986
• Publication Number:
  US 20150295198A1
• Time in Patent Office: 753 Days
• Field of Search: 257/40
• US Class Current: 1/1
• CPC Class Codes: H10K 50/13 comprising stacked EL layers within one EL unit
• CPC Class Codes: H10K 85/342 comprising iridium
• CPC Class Codes: H10K 85/657 Polycyclic condensed heteroaromatic hydrocarbons
• CPC Class Codes: H10K 85/6572 comprising only nitrogen in the heteroaromatic polycondensed ring system, e.g. phenanthroline or carbazole
• CPC Class Codes: H10K 85/6576 comprising only sulfur in the heteroaromatic polycondensed ring system, e.g. benzothiophene

Abstract

Organic light emitting devices (OLEDs) are provided that include two red emissive dopants. The two dopants may be disposed within a common organic emissive layer in an OLED, or each may be disposed in a separate layer. Configurations including multiple layers having multiple dopants are also provided, in which a first red dopant is disposed in a separate organic layer from a second red dopant, and a common dopant of another color, such as green, is disposed in each organic layer. Devices as disclosed herein are capable of providing an R9 value of at least 80, and of providing white light with a CRI of at least 80.

Claims

1. A first organic light emitting device comprising:

an anode;

a cathode;

a first emissive dopant disposed between the anode and the cathode, having a peak wavelength of 600 to 700 nanometers; and

a second emissive dopant disposed between the anode and the cathode, having a peak wavelength of 600 to 700 nanometers,

wherein the peak wavelength of the first emissive dopant is at least 4 nm less than the peak wavelength of the second emissive dopant, and wherein the device emits white light.

2. The device of claim 1, wherein the device emits light having a CRI of 80 or above.

3. The device of claim 1, wherein the first emissive dopant has a peak wavelength of 600 to 635.

4. The device of claim 1, wherein the second emissive dopant has a peak wavelength of 620 to 700.

5. The device of claim 1, further comprising a first emissive layer disposed between the anode and the cathode, wherein the first emissive dopant is disposed in the first emissive layer.

6. The device of claim 5, wherein the second emissive dopant is disposed in the first emissive layer.

7. The device of claim 5, further comprising a second emissive layer disposed between the anode and the cathode, wherein the second emissive dopant is disposed in the second emissive layer.

8. The device of claim 7, wherein the second emissive layer is disposed over the first emissive layer.

9. The device of claim 1, wherein the first emissive dopant is disposed in the first organic layer.

10. The device of claim 1, wherein the device has an R9 value of at least 80.

11. The device of claim 1, wherein the first red emissive dopant comprises a phosphorescent emissive material.

12. The device of claim 1, wherein the first emissive dopant emits light via thermally delayed active fluorescence.

13. The device of claim 1, further comprising a third emissive dopant disposed Between the anode and the cathode.

14. The device of claim 13, wherein the third emissive dopant is disposed in a third organic layer disposed between the anode and the cathode.

15. The device of claim 14, further comprising a fourth emissive dopant disposed between the anode and the cathode.

16. The device of claim 15, wherein the fourth emissive dopant is disposed in an organic layer separate from an organic layer in which the first emissive dopant is disposed.

17. The device of claim 16, wherein the fourth emissive dopant is disposed in an organic layer separate from an organic layer in which the second emissive dopant is disposed.

18. The device of claim 17, wherein the first and second emissive dopants are disposed in a common organic layer.

19. The device of claim 13, wherein the first emissive dopant is disposed in a first organic layer disposed between the anode and the cathode.

20. The device of claim 19, wherein the second emissive dopant is disposed in a second organic layer disposed between the anode and the cathode.