Four component phosphorescent OLED for cool white lighting application

• US 9,655,199 B2
• Filed: 05/30/2012
• Issued: 05/16/2017
• Est. Priority Date: 05/30/2012
• Status: Active Grant

• Current Assignee: Universal Display Corporation
• Original Assignee: Universal Display Corporation
• Inventors: Xu, Xin, Brown, Julia J., Weaver, Michael
• Primary Examiner(s): Patel, Nimeshkumar
• Assistant Examiner(s): RAABE, CHRISTOPHER M
• Application Number:
  US13/483,738
• Publication Number:
  US 20130320837A1
• Time in Patent Office: 1,812 Days
• Field of Search: 313498-512, 3151693, 345 36, 345 45, 345 76, 445 3, 445 23, 445 52
• CPC Class Codes: C09K 2211/1007 Non-condensed systems
• CPC Class Codes: C09K 2211/1029 containing one nitrogen atom as the heteroatom
• CPC Class Codes: C09K 2211/1044 containing two nitrogen atoms as heteroatoms
• CPC Class Codes: C09K 2211/185 of the platinum group, i.e. Os, Ir, Pt, Ru, Rh or Pd
• CPC Class Codes: H05B 33/14 characterised by the chemical or physical composition or the arrangement of the electroluminescent material , or by the simultaneous addition of the electroluminescent material in or onto the light source
• CPC Class Codes: H05B 33/145 Arrangements of the electroluminescent material
• CPC Class Codes: H10K 2101/10 Triplet emission
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 50/13 comprising stacked EL layers within one EL unit
• CPC Class Codes: H10K 59/32 Stacked devices having two or more layers, each emitting at different wavelengths
• 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

A light emitting system is provided including a first organic light emitting device. The first organic light emitting device includes an anode, a cathode, a first organic emitting layer disposed between the anode and the cathode, and a second organic emitting layer disposed between the anode and the cathode. The first organic emitting layer and the second organic emitting layer each include an emissive dopant having a peak wavelength of between 400 to 500 nanometers, but one of the peak wavelength of one of the dopants is at least 4 nm less than the peak wavelength of the other dopant. The first organic emitting layer and the second organic emitting layer may overlap each other, such as being disposed one over the other. The device may be used in white light or multi-color systems.

Claims

1. A light emitting system comprising a first organic light emitting device, the first organic light emitting device including:

an anode;

a cathode;

a first organic emitting layer, disposed between the anode and the cathode, comprising a first emissive dopant having a peak wavelength of between 400 to 500 nanometers; and

a second organic emitting layer, disposed between the anode and the cathode, comprising a second emissive dopant having a peak wavelength of between 400 to 500 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,

wherein the only organic emitting layers in the first organic light emitting device are the first organic emitting layer and the second organic emitting layer.

2. The system of claim 1, wherein the first organic emitting layer and the second organic emitting layer overlap at least partially in plan view.

3. The system of claim 1, further comprising at least a second organic light emitting device and a third organic light emitting device, each of the second and third light emitting devices configured to emit light at wavelengths of greater than 500 nanometers.

4. The system of claim 1, wherein the first emissive dopant has a peak wavelength of between 400 to 470 nanometers, and the second emissive dopant has a peak wavelength of between 460 to 500 nanometers.

5. The system of claim 4, wherein the first emissive dopant is disposed vertically adjacent to the second emissive dopant.

6. The system of claim 1, wherein the first emissive dopant and the second emissive dopant are disposed one over the other.

7. The system of claim 1, wherein the first organic light emitting device is configured such that the first emissive dopant and the second emissive dopant are only activated together.

8. The system of claim 1, wherein the first organic light emitting device is a white light emitter, including a plurality of different spectrum emitting layers stacked over one another.

9. The system of claim 1, wherein CCT of the system is >

4500K.

15. The system of claim 1, wherein the first emissive dopant comprises a phosphorescent blue emitter and the second emissive dopant comprises a phosphorescent blue emitter.

16. The system of claim 1, wherein the second organic emitting layer is separated from the first organic emitting layer by at least one charge generation layer (CGL).

10. A light emitting system comprising a first organic light emitting device, the first organic light emitting device including:

an anode;

a cathode;

a first organic emitting layer, disposed between the anode and the cathode, comprising a first emissive dopant having a peak wavelength of between 400 to 470 nanometers; and

a second organic emitting layer, disposed between the anode and the cathode, comprising a second emissive dopant having a peak wavelength of between 460 to 500 nanometers;

wherein the first emissive dopant and the second emissive dopant are disposed one over the other in a stack of layers of the first organic light emitting device, and

wherein the only organic emitting layers in the first organic light emitting device are the first organic emitting layer and the second organic emitting layer.

11. The system of claim 10, wherein the first organic layer is disposed in a first stack and the second organic layer is disposed in a second stack, the first and second stacks disposed one over the other.

12. The system of claim 10, wherein the first organic light emitting device is configured such that the first emissive dopant and the second emissive dopant are only activated together.

13. The system of claim 10, wherein the first organic light emitting device is a white light emitter, including a plurality of different spectrum emitting layers stacked over one another.

14. The system of claim 10, wherein CCT of the system is >

4500K.

17. The system of claim 10, wherein the second organic emitting layer is separated from the first organic emitting layer by at least one charge generation layer (CGL).

18. The system of claim 10, further comprising at least a second organic light emitting device and a third organic light emitting device, each of the second and third light emitting devices configured to emit light at wavelengths of greater than 500 nanometers.