Full color light emitting diode display

• US 5,583,349 A
• Filed: 11/02/1995
• Issued: 12/10/1996
• Est. Priority Date: 11/02/1995
• Status: Expired due to Term

• Current Assignee: Universal Display Corporation
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Holm, Paige M., Norman, Michael P.
• Primary Examiner(s): TRAN, MINH LOAN
• Application Number:
  US08/552,154
• Time in Patent Office: 404 Days
• Field of Search: 257/13, 257/88, 257/89, 257/90, 257/91, 257/92, 257/94, 257/96, 257/103, 257/40
• US Class Current: 257/88
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 25/0756 Stacked arrangements of devices
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 33/0025 comprising only AIIIBV compounds
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• 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 59/32 Stacked devices having two or more layers, each emitting at different wavelengths

Abstract

A full color light emitting diode display (310) utilizes semiconductor light emitting diodes (313) to produce red light and organic light emitting diodes (312) to produce blue light. Green light is produced by either semiconductor light emitting diodes (313) or by organic light emitting diodes (331). An array of semiconductor light emitting diodes is formed on a semiconductor substrate (322) and an array of organic light emitting diodes is also formed on semiconductor substrate (322) adjacent to the array of semiconductor light emitting diodes. The array of organic light emitting diodes cooperates with the array of semiconductor light emitting diodes to form an array of multi-wavelength pixels of the full color light emitting diode display (310).

Claims

1. A full color light emitting diode display comprising:

a semiconductor substrate;

a first light emitting diode constructed to emit light of a first wavelength and a second light emitting diode constructed to emit light of a second wavelength, different than the first wavelength, the first and second light emitting diodes being semiconductor light emitting diodes constructed on the semiconductor substrate and stacked together and positioned to both emit light in the same direction wherein one of the first and second light emitting diodes is transparent to light emitted by another of the first and second light emitting diodes; and

a third light emitting diode that is an organic light emitting diode formed on the semiconductor substrate and constructed to emit light of a third wavelength wherein the third light emitting diode cooperates with the first and second light emitting diodes to generate a pixel of the display.

2. The full color light emitting diode display of claim 1 wherein one of the first and second light emitting diodes emits light of a shorter wavelength than other of the first and second light emitting diodes.

3. The full color light emitting diode display of claim 2 wherein the light emitted by one of the first and second light emitting diodes is green and light emitted by another of the first and second light emitting diodes is red.

4. The full color light emitting diode display of claim 1 wherein light emitted by the first, second, and third light emitting diodes is visible light.

5. The full color light emitting diode display of claim 1 wherein each of the first and second light emitting diodes includes an active layer of material sandwiched between two confinement layers of material.

6. The full color light emitting diode display of claim 1 wherein light emitted by the first, second, and third light emitting diodes cooperates to form an image of the full color light emitting diode display.

7. A full color light emitting diode display comprising:

a semiconductor substrate;

a first light emitting diode that is a semiconductor light emitting diode formed on the semiconductor substrate and constructed to emit light of a first wavelength; and

a second light emitting diode having a first and a second light emitting element, the first light emitting element constructed to emit light of a second wavelength, different from the first wavelength and the second light emitting element constructed to emit light of a third wavelength, different than the first and second wavelengths, the second light emitting diode being an organic light emitting diode constructed on the semiconductor substrate wherein the second light emitting diode emits light in the same direction as the first light emitting diode and cooperate with the first light emitting diode to generate a pixel of the full color light emitting diode display.

8. The full color light emitting diode display of claim 7 wherein the light emitted by one of the first and second light emitting elements is green and the light emitted by another of the first and second light emitting elements is blue.

9. The full color light emitting diode display of claim 7 wherein each of the first and second light emitting elements includes a low work function conductor that is an electron supply layer formed on the semiconductor substrate, a first color organic layer positioned on the electron supply layer, a second color organic layer on the first color organic layer wherein the second color organic layer has a defined area for a hole supply conductor, the second light emitting element having a third color organic layer on a portion of the second color organic layer wherein the third color organic layer has defined area for a hole supply conductor, and the first and second light emitting elements having an optically transparent hole supply conductor on the defined area.

10. A full color light emitting diode display comprising:

a semiconductor substrate having an array of semiconductor light emitting diodes; and

an array of organic light emitting diodes on the semiconductor substrate wherein the array of organic light emitting diodes cooperates with the array of semiconductor light emitting diodes, one semiconductor light emitting diode associated with each organic light emitting diode to define a pixel, to form an array of pixels of the full color light emitting diode display.

11. The full color light emitting diode display of claim 10 wherein each semiconductor light emitting diode of the array of semiconductor light emitting diodes includes a multi-wavelength semiconductor light emitting diode that emits a first wavelength of light and a second wavelength of light that is different than the first wavelength of light.

12. The full color light emitting diode display of claim 11 wherein each organic light emitting diode of the array of organic light emitting diodes emits a third wavelength of light that is different than the first and second wavelengths of light.

13. The full color light emitting diode display of claim 10 wherein each semiconductor light emitting diode of the array of semiconductor light emitting diodes emits a first wavelength of light that is in a visible spectrum of light.

14. The full color light emitting diode display of claim 13 wherein each organic light emitting diode of the array of organic light emitting diodes includes two light emitting elements wherein a first light emitting element emits a second wavelength of light that is different than the first wavelength of light, and a second light emitting element emits a third wavelength of light that is different than the first and second wavelengths of light.

15. The full color light emitting diode display of claim 14 wherein each of the first and second light emitting elements includes a low work function conductor that is an electron supply layer formed on the semiconductor substrate, a first color organic layer positioned on the electron supply layer, a second color organic layer on the first color organic layer wherein the second color organic layer has a defined area for a hole supply conductor, the second light emitting element having a third color organic layer on a portion of the second color organic layer wherein the third color organic layer has defined area for a hole supply conductor, and the first and second light emitting elements having an optically transparent hole supply conductor on the defined area.