Devices Combining Thin Film Inorganic LEDs with Organic LEDs and Fabrication Thereof

• US 20170025484A1
• Filed: 11/26/2014
• Published: 01/26/2017
• Est. Priority Date: 11/27/2013
• Status: Active Grant

• Current Assignee: Board of Regents of the University of Michigan (University of Michigan)
• Original Assignee: Board of Regents of the University of Michigan (University of Michigan)
• Inventors: FORREST, Stephen R., LEE, Kyusang
• Granted Patent: US 10,062,738 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G09G 2300/0452 Details of colour pixel setup, e.g. pixel composed of a red, a blue and two green components
• CPC Class Codes: G09G 3/32 semiconductive, e.g. using light-emitting diodes [LED]
• CPC Class Codes: G09G 3/3208 organic, e.g. using organic light-emitting diodes [OLED]
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H10K 59/00 Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
• CPC Class Codes: H10K 59/1201 Manufacture or treatment
• CPC Class Codes: H10K 59/32 Stacked devices having two or more layers, each emitting at different wavelengths
• CPC Class Codes: H10K 59/35 comprising red-green-blue [RGB] subpixels
• CPC Class Codes: H10K 59/352 the areas of the RGB subpixels being different
• CPC Class Codes: H10K 59/38 comprising colour filters or colour changing media [CCM]
• CPC Class Codes: H10K 59/70 OLEDs integrated with inorganic light-emitting elements, e.g. with inorganic electroluminescent elements
• CPC Class Codes: H10K 71/00 Manufacture or treatment specially adapted for the organic devices covered by this subclass
• CPC Class Codes: H10K 71/20 Changing the shape of the active layer in the devices, e.g. patterning
• CPC Class Codes: H10K 71/80 using temporary substrates
• CPC Class Codes: H10K 77/111 Flexible substrates

Abstract

Devices including organic and inorganic LEDs are provided. Techniques for fabricating the devices include fabricating an inorganic LED on a parent substrate and transferring the LED to a host substrate via a non-destructive ELO process. Scaling techniques are also provided, in which an elastomeric substrate is deformed to achieve a desired display size.

Claims

1. A device comprising:

an inorganic first light-emitting diode (LED) disposed over a substrate;

an organic second LED (OLED) disposed over the substrate and adjacent to the first inorganic LED; and

a third LED disposed over the substrate and adjacent to the first LED or the second LED;

wherein each of the first, second, and third LEDs is individually addressable as a subpixel within the device.

2. The device of claim 1, wherein the third LED is an OLED.

3. The device of claim 1, wherein the third LED is an inorganic LED.

4. The device of claim 1, wherein the inorganic first LED is configured to emit blue light.

5. The device of claim 1, wherein the device is a device selected from the group consisting of:

a flat panel display, a computer monitor, a medical monitor, a television, a billboard, a light for interior or exterior illumination and/or signaling, a heads-up display, a fully or partially transparent display, a flexible display, a laser printer, a telephone, a cell phone, a tablet, a phablet, a personal digital assistant (PDA), a laptop computer, a digital camera, a camcorder, a viewfinder, a micro-display, a 3-D display, a vehicle, a large area wail, theater or stadium screen, and a sign.

6. A full-color display comprising a plurality of pixels, each of the pixels comprising a plurality of sub-pixels, wherein at least a first portion of sub-pixels in the display comprise OLEDs and at least a second portion of sub-pixels in the display comprise inorganic LEDs.

7. A method comprising:

depositing an epitaxial protective layer over an epitaxial substrate;

depositing an epitaxial sacrificial layer over the epitaxial protective layer;

depositing a plurality of emissive stacks over the epitaxial sacrificial layer;

cold-welding the emissive stack to a flexible substrate;

separating the epitaxial protective layer from the emissive stack;

applying one or more layers to each stack of the plurality of emissive stacks to form a first plurality of LEDs;

transferring a first portion of the first plurality of LEDs to a first host substrate; and

fabricating a second plurality of LEDs on the first host substrate.

8. The method of claim 7, wherein the second plurality of LEDs comprises OLEDs.

9. The method of claim 8, wherein the first plurality of LEDs are configured to emit blue light, and wherein the second plurality of LEDs comprises OLEDs configured to emit red light.

10. The method of claim 8, wherein the first plurality of LEDs are configured to emit blue light, and wherein the second plurality of LEDs comprises OLEDs configured to emit green light.

11. The method of claim 7, further comprising fabricating color altering layers over the first plurality of LEDs.

12. The method of claim 7, wherein the step of separating the epitaxial protective layer from the emissive stack is performed via an epitaxial lift-off (ELO) process.

13. The method of claim 12, wherein the ELO process is non-destructive of underlying layers.

14. The method of claim 7, wherein the epitaxial substrate comprises a material selected from the group consisting of:

GaN, sapphire, GaAs, Si, InP, and GaSh.

15. The method of claim 7, further comprising:

transferring a second portion of the first plurality of LEDs to a second host substrate; and

fabricating a third plurality of LEDs on the second host substrate.

16. The method of claim 15, wherein the third plurality of LEDs comprises OLEDs.

17. The method of claim 7, further comprising:

deforming the first host substrate to increase the distance between adjacent LEDs on the host substrate.

18. The method of claim 17, wherein the deforming comprises stretching the first host substrate.

19. The method of claim 17, wherein the deforming comprises applying pressure to the first host substrate with a curved surface.

20. The method of claim 19, wherein the curved surface comprises a device selected from the group consisting of:

a rigid roll, a pin, a vacuum mold, and a spherical surface.

21. (canceled)

22. (canceled)