Top emission AMOLED displays using two emissive layers
Full-color pixel arrangements for use in devices such as OLED displays are provided, in which multiple sub-pixels are configured to emit different colors of light, with each sub-pixel having a different optical path length than some or all of the other sub-pixels within the pixel.
1. A full-color pixel arrangement for an OLED display comprising:
a substrate; and
a plurality of pixels, each pixel comprising emissive regions of exactly two colors disposed laterally adjacent to one another over the substrate, each pixel of the plurality of pixels comprising:
a first sub-pixel configured to emit light of a first color, the first sub-pixel having a first optical path length; and
a second sub-pixel configured to emit light of a second color, the second sub-pixel having a second optical path length different than the first optical path length.
2. The arrangement of claim 1 , wherein at least one pixel of the plurality of pixels further comprises:
a third sub-pixel configured to emit light of a third color, the third sub-pixel having a third optical path length different than the first optical path length.
3. The arrangement of claim 2 , further comprising a fourth sub-pixel configured to emit light of a fourth color, the fourth sub-pixel having a fourth optical path length different than the first optical path length.
4. The arrangement of claim 3 , wherein the fourth optical path length is different than at least one of the second and third optical path lengths.
5. The arrangement of claim 4 , wherein each of the first, second, third, and fourth optical path lengths is different than each of the other of the first, second, third, and fourth optical path lengths.
6. The arrangement of claim 5 , further comprising:
a first electrode stack disposed in a stack with each of the first, second, third, and fourth sub-pixels;
wherein a first portion of the first electrode stack disposed in a stack with the first sub-pixel has a different thickness than a second portion of the first electrode stack, a third portion of the first electrode stack, and a fourth portion of the first electrode stack, wherein the second, third, and fourth portions are each disposed in a stack with the second, third, and fourth sub-pixels, respectively.
7. The arrangement of claim 6 , wherein each of the first, second, third, and fourth sub-pixels comprises at least one organic layer that is the same thickness as in each of the other of the first, second, third, and fourth sub-pixels.
8. The arrangement of claim 1 , wherein the total thickness of organic layers in the first sub-pixel is the same as the total thickness of organic layers in the second sub-pixel.
9. The arrangement of claim 1 , wherein the total optical path length of organic layers in the first sub-pixel is the same as the total optical path length of organic layers in the second sub-pixel.
10. The arrangement of claim 2 , wherein the total thickness of organic layers in the first, second, and third sub-pixels is the same.
11. The arrangement of claim 2 , wherein the total optical path length of organic layers in the first, second, and third sub-pixels is the same.
12. The arrangement of claim 1 , wherein the thickness of each type of organic layer is the same in each of the first and second sub-pixels.
13. The arrangement of claim 2 , wherein the thickness of each type of organic layer is the same in each of the first, second, and third sub-pixels.
14. The arrangement of claim 1 , further comprising:
a first electrode stack disposed in a stack with each of the first, second, and third sub-pixels;
wherein a first portion of the first electrode stack disposed in a stack with the first sub-pixel has a different thickness than a second portion of the first electrode stack disposed in a stack with the second sub-pixel.
15. The arrangement of claim 14 , wherein a third portion of the first electrode disposed in a stack with the first sub-pixel has a different thickness than the first portion of the first electrode.
16. The arrangement of claim 2 , wherein each of the first, second, and third sub-pixels comprises a transport layer having a different thickness than a respective transport layer in each of the other sub-pixels.
17. The arrangement of claim 1 , wherein each pixel comprises not more than two color altering layers.
18. The arrangement of claim 1 , wherein:
the first sub-pixel comprises an emissive region of a first color; and
the second sub-pixel comprises an emissive region of a second color.
19. A device comprising the full-color pixel arrangement of claim 1 , wherein the device is a type selected from the group consisting of: a wearable device, a flat panel display, a computer monitor, a medical monitor, a television, a billboard, a light for interior or exterior illumination, a signal, a color tunable or color temperature tunable lighting source, a heads-up display, a fully transparent display, a flexible display, a 3D display, a laser printer, a telephone, a cell phone, a personal digital assistant (PDA), a laptop computer, a digital camera, a camcorder, a viewfinder, a micro-display, a vehicle, a large area wall, a theater or stadium screen, and a sign.
20. A method of fabricating a full-color pixel in an emissive device, the method comprising:
fabricating a transparent layer over a substrate, the transparent layer comprising a first region and a second region, at least one optical characteristic being different between the first and second regions;
fabricating a first organic emissive stack comprising a first emissive region of a first color over the first region; and
fabricating a second organic emissive stack comprising a second emissive region of a second color over the second region;
wherein the pixel comprises emissive regions of not more than two colors.