Cascaded organic electroluminescent devices with color filters

• US 20050029933A1
• Filed: 09/02/2004
• Published: 02/10/2005
• Est. Priority Date: 02/15/2002
• Status: Abandoned Application

• Current Assignee: Eastman Kodak Company
• Original Assignee: Eastman Kodak Company
• Inventors: Liao, Liang-Sheng, Cok, Ronald S., Arnold, Andrew D., Tang, Ching W.
• Application Number:
  US10/932,761
• Publication Number:
  US 20050029933A1
• Time in Patent Office: Days
• US Class Current: 313/504
• CPC Class Codes: H05B 45/60 Circuit arrangements for operating LEDs comprising organic material, e.g. for operating organic light-emitting diodes [OLED] or polymer light-emitting diodes [PLED]
• CPC Class Codes: H10K 2101/10 Triplet emission
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 50/125 specially adapted for multicolour light emission, e.g. for emitting white light
• CPC Class Codes: H10K 50/19 Tandem OLEDs
• CPC Class Codes: H10K 59/12 Active-matrix OLED [AMOLED] displays
• CPC Class Codes: H10K 59/17 Passive-matrix OLED displays
• CPC Class Codes: H10K 59/35 comprising red-green-blue [RGB] subpixels
• CPC Class Codes: H10K 59/38 comprising colour filters or colour changing media [CCM]
• CPC Class Codes: H10K 85/30 Coordination compounds
• CPC Class Codes: H10K 85/341 Transition metal complexes, e.g. Ru(II)polypyridine complexes H10K85/331 takes precedence
• CPC Class Codes: H10K 85/342 comprising iridium
• CPC Class Codes: H10K 85/351 Metal complexes comprising lanthanides or actinides, e.g. comprising europium
• CPC Class Codes: H10K 85/615 Polycyclic condensed aromatic hydrocarbons, e.g. anthracene
• CPC Class Codes: H10K 85/631 Amine compounds having at least two aryl rest on at least one amine-nitrogen atom, e.g. triphenylamine
• CPC Class Codes: H10K 85/649 Aromatic compounds comprising a hetero atom
• CPC Class Codes: Y02B 20/30 Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]
• CPC Class Codes: Y10S 428/917 Electroluminescent
• CPC Class Codes: Y10T 428/26 Web or sheet containing structurally defined element or component, the element or component having a specified physical dimension

Abstract

An OLED device is described comprising a substrate having thereon a cascaded organic electroluminescent device comprising: a) an anode; b) a cathode; c) a plurality of cascaded organic electroluminescent units disposed between the anode and the cathode, wherein each organic electroluminescent unit includes at least one light-emitting layer and wherein the plurality of cascaded units includes at least two units that emit light of different colors; and d) a connecting unit disposed between each adjacent cascaded organic electroluminescent unit; and e) a colored filter that filters the emitted light.

Claims

1. An OLED device comprising a substrate having thereon a cascaded organic electroluminescent device comprising:

a) an anode;

b) a cathode;

c) a plurality of cascaded organic electroluminescent units disposed between the anode and the cathode, wherein each organic electroluminescent unit includes at least one light-emitting layer and wherein the plurality of cascaded units includes at least two units that emit light of different colors; and

d) a connecting unit disposed between each adjacent cascaded organic electroluminescent unit; and

e) a colored filter that filters the emitted light.

2. The OLED device of claim 1, comprising a plurality of anodes defining independently controlled light-emitting areas of the OLED device, wherein the plurality of cascaded organic electroluminescent units are disposed between the plurality of anodes and a common cathode.

3. The OLED device of claim 2, wherein at least two independently controlled light-emitting areas have differently colored filters that filter the emitted light.

4. The OLED device of claim 3, wherein the colors of the light transmitted by the differently colored filters are matched to the colors of the light emitted by one of the plurality of organic electroluminescent units.

5. The OLED device of claim 4 wherein the cascaded organic electroluminescent units include units that individually emit red, green, and blue light.

6. The OLED device of claim 3 wherein the cascaded organic electroluminescent units include units that in combination emit white light.

7. The OLED device of claim 6 wherein the color filters transmit red, green, or blue light.

8. The OLED device of claim 3 wherein the efficiency of light emission from or lifetime of one of the cascaded organic electroluminescent units is different from the efficiency of light emission from or lifetime of another of the organic electroluminescent units.

9. The OLED device of claim 8 wherein the relative size of an independently controlled light-emitting area and associated color filter is inversely related to the relative efficiency of light emission from or lifetime of the cascaded organic electroluminescent units.

10. The OLED device of claim 8 wherein the cascaded organic electroluminescent units are ordered in a stack to correspond to the relative efficiency of light emission from the organic electroluminescent units in the stack.

11. The OLED device of claim 8 wherein the cascaded organic electroluminescent units are ordered in a stack to minimize the relative absorption of light emission from the organic electroluminescent units in the stack as the light passes through the stack.

12. The OLED device of claim 3 further comprising an independently controlled light-emitting area and cascaded organic electroluminescent unit without a corresponding color filter.

13. The OLED device of claim 12 wherein the independently controlled light-emitting area without a corresponding color filter emits white light.

14. The OLED device of claim 1 wherein two of the cascaded organic electroluminescent units emit light of the same color.

15. The OLED device of claim 1 wherein the light is emitted through the substrate.

16. The OLED device of claim 1 further comprising a cover formed over the cascaded organic electroluminescent units wherein the light is emitted through the cover.

17. The OLED device of claim 1 comprising two cascaded organic electroluminescent units that emit green and white light respectively.

18. The OLED device of claim 1 comprising two cascaded organic electroluminescent units that emit blue and yellow light respectively.

19. The OLED device of claim 1 comprising two cascaded organic electroluminescent units that emit red and cyan light respectively.

20. The OLED device of claim 1 comprising two cascaded organic electroluminescent units that emit green and magenta light respectively.

21. The OLED device of claim 1, wherein the connecting unit comprises a doped organic layer.

22. The OLED device of claim 21, wherein the connecting unit comprises, in sequence, an n-type doped organic layer, and a p-type doped organic layer.