Reducing angular dependency in microcavity color OLEDs
View Patent ↗A microcavity color OLED device, includes at least one light-emitting layer arranged so as to produce light; a reflector and a semi-transparent reflector forming a microcavity structure for resonating the light produced in the at least one light emitting layer; and a color filter element disposed over the microcavity structure including a light-scattering material selected so as to reduce the angular dependence of the light that has passed through the color filter element.
1. A microcavity color OLED device, comprising:
a) at least one light-emitting layer arranged so as to produce light;
b) a reflector and a semi-transparent reflector forming a microcavity structure for resonating the light produced in the at least one light emitting layer; and
c) a color filter element disposed over the microcavity structure including a light-scattering material selected so as to reduce the angular dependence of the light that has passed through the color filter element.
2. The microcavity color OLED device of claim 1 where the reflector, the semi-transparent reflector, or both, also serve as electrodes for the light emitting layer.
3. The microcavity color OLED device of claim 1 where the semi-transparent reflector is Ag or an alloy containing Ag.
4. The microcavity color OLED device of claim 1 where the device is top-emitting.
5. The microcavity color OLED device of claim 1 where the device is bottom-emitting.
6. The microcavity color OLED device of claim 1 wherein the light-scattering material is particulate and the particles are nanoparticles.
7. The microcavity color OLED device of claim 6 wherein the light-scattering material particles are in a range of from 125 to 500 nm.
8. The microcavity color OLED device of claim 7 wherein the color filter element is a blue color filter element and the light-scattering material particles are in a range of from 125 to 350 nm.
9. The microcavity color OLED device of claim 7 wherein the color filter element is a green color filter element and the light-scattering material particles are in a range of from 150 to 400 nm.
10. The microcavity color OLED device of claim 7 wherein the color filter element is a blue color filter element and the light-scattering material particles are in a range of from 175 to 500 nm.
11. The microcavity color OLED device of claim 1 wherein the light-scattering material has a refractive index greater than 1.25 times the refractive index of the color filter element medium.
12. The microcavity color OLED device of claim 11 wherein the light-scattering material includes magnesium oxide, titanium dioxide, zirconium oxide, beryllium oxide, tin sulfide, or zinc selenide, or combinations thereof.
13. A microcavity color OLED device, comprising:
a) at least one light-emitting layer arranged so as to produce light;
b) a reflector and a semi-transparent reflector forming a microcavity structure for resonating the light produced in the at least one light emitting layer; and
c) a color filter element disposed over the microcavity structure including a selective light-absorbing material, a light-scattering material separate from the selective light-absorbing material or part of the selective light-absorbing material or both and selected so as to reduce the angular dependence of the light that has passed through the color filter element.
14. The microcavity color OLED device of claim 13 wherein the light-scattering material is particulate and the particles are nanoparticles.
15. The microcavity color OLED device of claim 14 wherein the light-scattering material particles are in a range of from 125 to 500 nm.
16. The microcavity color OLED device of claim 15 wherein the color filter element is a blue color filter element and the light-scattering material particles are in a range of from 125 to 350 nm.
17. The microcavity color OLED device of claim 15 wherein the color filter element is a green color filter element and the light-scattering material particles are in a range of from 150 to 400 nm.
18. The microcavity color OLED device of claim 15 wherein the color filter element is a blue color filter element and the light-scattering material particles are in a range of from 175 to 500 nm.
19. The microcavity color OLED device of claim 13 wherein the light-scattering material has a refractive index greater than 1.25 times the refractive index of the color filter element medium.
20. The microcavity color OLED device of claim 19 wherein the light-scattering material includes magnesium oxide, titanium dioxide, zirconium oxide, beryllium oxide, tin sulfide, or zinc selenide, or combinations thereof.
21. The microcavity color OLED device of claim 13 where the reflector, the semi-transparent reflector, or both, also serve as electrodes for the light emitting layer.
22. The microcavity color OLED device of claim 13 where the semi-transparent reflector is Ag or an alloy containing Ag.
23. The microcavity color OLED device of claim 13 where the device is top-emitting.
24. The microcavity color OLED device of claim 13 where the device is bottom-emitting.
25. A full color OLED device having an array of pixels which include different subpixels that emit different color light and wherein each subpixel comprises:
a) at least one light emitting layer arranged to produce light, wherein the light produced by each subpixel is a different color;
b) a reflector and a semi-transparent reflector forming a microcavity structure for resonating the light produced in the at least one light emitting layer; and
c) a color filter element disposed over the microcavity structure including a selective light-absorbing material, a light scattering material separate from the selective light-absorbing material or part of the selective light-absorbing material or both and selected so as to reduce the angular dependence of the light that has passed through the color filter element.
26. The full color OLED device of claim 25 wherein the light-scattering material is particulate and the particles are nanoparticles.
27. The full color OLED device of claim 26 wherein the light scattering material particles are in a range of from 125 to 500 nm.
28. The full color OLED device of claim 27 wherein the color filter element is a blue color filter element and the light-scattering material particles are in a range of from 125 to 350 nm.
29. The full color OLED device of claim 27 wherein the color filter element is a green color filter element and the light-scattering material particles are in a range of from 150 to 400 nm.
30. The full color OLED device of claim 27 wherein the color filter element is a blue color filter element and the light-scattering material particles are in a range of from 175 to 500 nm.
31. The full color OLED device of claim 25 wherein the light-scattering material has a refractive index greater than 1.25 times the refractive index of the color filter element medium.
32. The full color OLED device of claim 31 wherein the light-scattering material includes magnesium oxide, titanium dioxide, zirconium oxide, beryllium oxide, tin sulfide, or zinc selenide, or combinations thereof.
33. The full color OLED device of claim 25 where the reflector, the semi-transparent reflector, or both, also serve as electrodes for the light emitting layer.
34. The full color OLED device of claim 25 where the semi-transparent reflector is Ag or an alloy containing Ag.
35. The full color OLED device of claim 25 where the device is top-emitting.
36. The full color OLED device of claim 25 where the device is bottom-emitting.