LIGHT EMITTING DEVICE INCLUDING TANDEM STRUCTURE

• US 20160079316A1
• Filed: 03/11/2015
• Published: 03/17/2016
• Est. Priority Date: 09/14/2012
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: QD Vision, Inc. (Samsung Electronics Co. Ltd.)
• Inventors: ZHOU, Zhaoqun, Kazlas, Peter T.
• Granted Patent: US 9,865,659 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01L 33/06 within the light emitting region, e.g. quantum confinement structure or tunnel barrier
• CPC Class Codes: H10K 2102/331 Nanoparticles used in non-emissive layers, e.g. in packaging layer
• CPC Class Codes: H10K 50/115 comprising active inorganic nanostructures, e.g. luminescent quantum dots
• CPC Class Codes: H10K 50/131 with spacer layers between the electroluminescent layers
• CPC Class Codes: H10K 50/15 Hole transporting layers
• CPC Class Codes: H10K 50/17 Carrier injection layers
• CPC Class Codes: H10K 50/19 Tandem OLEDs
• 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

Abstract

A light emitting device comprising: a pair of electrodes; two or more light emitting elements disposed between the electrodes in a stacked arrangement, wherein a light emitting element comprises a layer comprising an emissive material; and a charge generation element disposed between adjacent light emitting elements in the stacked arrangement, the charge generation element comprising a first layer comprising an inorganic n-type semiconductor material, and a second layer comprising a hole injection material. A charge generation element is also disclosed.

Claims

1. A light emitting device comprising:

a pair of electrodes;

two or more light emitting elements disposed between the electrodes in a stacked arrangement, wherein a light emitting element comprises a layer comprising an emissive material; and

a charge generation element disposed between adjacent light emitting elements in the stacked arrangement, the charge generation element comprising a first layer comprising an inorganic n-type semiconductor material and a second layer comprising a hole injection material.

2. A light emitting device in accordance with claim 1 wherein the light emitting device is encapsulated.

3. A light emitting device in accordance with claim 1 wherein at least one light emitting element includes an emissive material comprising quantum dots.

4. A light emitting device in accordance with claim 1 wherein at least one light emitting element includes an emissive material comprising quantum dots with a monodisperse size distribution.

5. A light emitting device in accordance with claim 4 wherein at least one of the other light emitting elements includes an emissive material comprising an organic electroluminescent material.

6. A light emitting device in accordance with claim 1 wherein each of the light emitting elements includes an emissive material comprising quantum dots.

7. A light emitting device in accordance with claim 1 wherein each of the light emitting elements includes an emissive material comprising quantum dots with a monodisperse size distribution.

8. A light emitting device in accordance with claim 1 wherein the inorganic n-type semiconductor material comprises a Group II-VI compound, a Group III-V compound, a Group IV-VI compound, a Group I-III-VI compound, a Group II-IV-VI compound, a Group II-IV-V compound, a Group IV element, an alloy including any of the foregoing and/or a mixture including any of the foregoing.

9. A light emitting device in accordance with claim 1 wherein the inorganic n-type semiconductor material comprises nanoparticles of the inorganic n-type semiconductor material.

10. A light emitting device in accordance with claim 1 wherein the inorganic n-type semiconductor material comprises non-light emitting nanoparticles of the inorganic n-type semiconductor material.

11. A light emitting device in accordance with claim 1 wherein the inorganic n-type semiconductor material comprises nanoparticles of the inorganic n-type semiconductor material, wherein the nanoparticles are not surface passivated.

12. A light emitting device in accordance with claim 1 wherein the inorganic n-type semiconductor material comprises n-type zinc oxide nanoparticles.

13. A light emitting device in accordance with claim 1 wherein the hole injection material comprises an organic material without an inorganic dopant.

14. A light emitting device in accordance with claim 1 wherein the first layer comprising an inorganic n-type semiconductor material injects electrons into the contiguous light emitting element and the second layer comprising a hole injection material inject holes into the contiguous light emitting element.

15. A light emitting device in accordance with claim 1 wherein a light emitting element further comprises one or more additional layers.

16. A light emitting device in accordance with claim 1 wherein a light emitting element comprises:

a first layer comprising a charge transport material; and

a second layer comprising the emissive layer.

17. A light emitting device in accordance with claim 16 wherein the light emitting element further comprises a third layer comprising a second charge transport material on a side of the second layer opposite the first layer.

19. A light emitting device in accordance with claim 1 wherein the charge generation element is at least 80% transparent to light passage.

20. A light emitting device in accordance with claim 3 wherein the emissive layer comprising quantum dots is contiguous to the first layer of the charge generation element.

21. A light emitting device in accordance with claim 3 wherein the light emitting element contiguous to the second layer of the charge generation element includes a layer comprising a hole transport material between the emissive layer and the second layer.

18. (canceled)

22-29. -29. (canceled)