Organic light emitting devices for illumination

• US 8,100,734 B2
• Filed: 10/12/2006
• Issued: 01/24/2012
• Est. Priority Date: 08/16/2002
• Status: Expired due to Term

• Current Assignee: Universal Display Corporation
• Original Assignee: Universal Display Corporation
• Inventors: Hack, Michael, Lu, Min-Hao Michael, Weaver, Michael S.
• Primary Examiner(s): Patel, Nimeshkumar
• Assistant Examiner(s): PERRY, ANTHONY T
• Application Number:
  US11/580,590
• Publication Number:
  US 20070029906A1
• Time in Patent Office: 1,930 Days
• Field of Search: 313/498, 313/504, 445/24
• US Class Current: 445/24
• CPC Class Codes: F21Y 2105/00 Planar light sources
• CPC Class Codes: F21Y 2115/15 Organic light-emitting diodes [OLED]
• CPC Class Codes: H10K 50/85 Arrangements for extracting light from the devices
• CPC Class Codes: H10K 59/35 comprising red-green-blue [RGB] subpixels
• CPC Class Codes: H10K 59/875 Arrangements for extracting light from the devices

Abstract

An organic light emitting device an a method of obtaining illumination from such a device is provided. The device has a plurality of regions, each region having an organic emissive layer adapted to emit a different spectrum of light. The regions in combination emit light suitable for illumination purposes. The area of each region may be selected such that the device is more efficient than an otherwise equivalent device having regions of equal size. The regions may have an aspect ratio of at least about four. All parts of any given region may be driven at the same current.

Claims

1. A method of fabricating an illumination source, capable of producing light, having a CRI value of at least about 80, the method comprising:

fabricating a first stripe, having a first area, the first stripe comprising a first organic emissive layer, adapted to emit a first spectrum of light;

fabricating a second stripe, having a second area, the second stripe comprising a second organic emissive layer, adapted to emit a second spectrum of light;

wherein

each stripe has an aspect ratio greater than about 4 and a width greater than about 0.5 mm;

the first organic emissive layer in the first stripe emits the first spectrum of light, the second organic emissive layer in the second stripe emits the second spectrum of light, and the first spectrum of light is different from the second spectrum of light when voltages are applied across the first and second stripes; and

fabricating a drive circuitry for supplying a predetermined drive current to each stripe, which achieves a combination of light emitted from the emissive layers having a CRI value of at least about 80.

2. The method of claim 1, further comprising fabricating the first and second stripes so that the first area is different from the second area.

3. The method of claim 1, further comprising fabricating the stripes in a process comprising stamping emissive materials over a substrate.

4. The method of claim 1, further comprising fabricating the stripes in a process comprising depositing emissive materials by OVJD over a substrate.

5. The method of claim 1, further comprising fabricating each stripe with a width greater than about 5 mm.

6. The method of claim 1, wherein a combination of the first spectrum of light and the second spectrum of has a CIE of (0.33±

0.04, 0.33±

0.07).

7. The method of claim 1, further comprising providing color correction circuitry, adapted to individually control the current passing through each stripe to correct for any differential aging of the stripes.

8. The method of claim 1, further comprising fabricating a third stripe having a third organic emissive layer adapted to emit a third spectrum of light from a third organic emissive material;

wherein the third spectrum of light differs from the first and second spectra of light; and

a combination of the light emitted from the emissive layers has a CRI value greater than 80 when a voltage is applied across each of the stripes.

9. The method of claim 8, further comprising fabricating the third stripe to have an area different from the first and second areas of the first and second stripes.

10. The method of claim 8, further comprising fabricating the stripes in a process comprising stamping the emissive materials over a substrate.

11. The method of claim 8, further comprising fabricating the stripes in a process comprising depositing the emissive materials by OVJD over a substrate.

12. The method of claim 8, further comprising fabricating each stripe with a width greater than about 5 mm.

13. The method of claim 8, wherein the CRI value is greater than 85.

14. The method of claim 8, wherein the CRI value is greater than 90.

15. The method of claim 8, wherein the CRI value is greater than 95.

16. The method of claim 8, wherein the light has a CIE of (0.33±

0.04, 0.33±

0.07).

17. The method of claim 8, wherein the light has a CIE of (0.33±

0.02, 0.33±

0.02).

18. The method of claim 8, further comprising providing color correction circuitry adapted to individually control the current passing through each stripe to correct for any differential aging of the stripes.

19. A method of fabricating an illumination source, capable of producing light, having a CRI value of at least about 80, the method comprising:

fabricating a plurality of stripes, each stripe having an area, and comprising an organic emissive layer, adapted to emit a spectrum of light, wherein each stripe has an aspect ratio greater than about 4 and a width greater than about 0.5 mm;

when voltages are applied across the plurality of stripes, the stripes emit at least three different spectra of light; and

fabricating a drive circuitry for supplying a predetermined drive current to each stripe, which achieves a combination of the emitted spectra of light having a CRI value of at least about 80.

20. An organic light emitting device comprising a plurality of light-emitting regions, each of said regions comprising one organic emissive layer selected from a plurality of different organic emissive layers, wherein:

(a) each of the plurality of emissive layers is adapted to emit a different spectrum of light;

(b) the light-emitting regions are in the form of stripes having an aspect ratio greater than 4 and a width greater than 0.5 mm;

wherein the light emitting fill factor of the device exceeds 70%;

(c) the drive current for each different type of emissive layer is individually adjusted;

or the different types of emissive layers have different areas;

or both; and

(d) the device emits light having a CRI greater than 80 when power is provided to the plurality of light-emitting regions.

21. The device according to claim 20, comprising at least three different kinds of light-emitting regions, which respectively comprise:

(a) a first organic light emissive layer adapted to emit a first spectrum of light from a first emissive material;

(b) a second organic light emissive layer adapted to emit a second spectrum of light from a second emissive material; and

(c) a third organic light emissive layer adapted to emit a third spectrum of light from a third emissive material.

22. The device according to claim 20, comprising only three different kinds of light-emitting regions, which respectively comprise:

(a) a first organic light emissive layer adapted to emit a first spectrum of light from a first emissive material;

(b) a second organic light emissive layer adapted to emit a second spectrum of light from a second emissive material; and

(c) a third organic light emissive layer adapted to emit a third spectrum of light from a third emissive material.

23. The device according to claim 22, wherein the first, second and third emissive layers do not all have equal areas.

24. The device according to claim 20, comprising only two different kinds of light-emitting regions, which respectively comprise:

(a) a first organic light emissive layer adapted to emit a first spectrum of light from a first emissive material; and

(b) a second organic light emissive layer adapted to emit a second spectrum of light from a second emissive material.

25. The device according to claim 24, wherein the first and second emissive layers do not have equal areas.

26. The device according to claim 20, wherein the emitted light has a CIE of (0.33+/−

0.04, 0.33+/−

0.07).

27. The device according to claim 20, wherein the width of the light-emitting regions is greater than 5 mm.