Inorganic light-emitting diode with encapsulating reflector

• US 9,537,069 B1
• Filed: 06/30/2015
• Issued: 01/03/2017
• Est. Priority Date: 09/25/2014
• Status: Active Grant

• Current Assignee: X Display Company Technology Limited (Sensinnovat BVBA)
• Original Assignee: X-Celeprint Limited
• Inventors: Bower, Christopher, Meitl, Matthew
• Primary Examiner(s): Sarkar, Asok K
• Assistant Examiner(s): Withers, Grant
• Application Number:
  US14/788,632
• Publication Number:
  US 20170005244A1
• Time in Patent Office: 553 Days
• Field of Search: 257/98
• US Class Current: 1/1
• CPC Class Codes: H01L 27/156 two-dimensional arrays
• CPC Class Codes: H01L 33/38 with a particular shape
• CPC Class Codes: H01L 33/385 the electrode extending at least partially onto a side surface of the semiconductor body
• CPC Class Codes: H01L 33/405 Reflective materials
• CPC Class Codes: H01L 33/46 Reflective coating, e.g. dielectric Bragg reflector
• CPC Class Codes: H01L 33/54 having a particular shape
• CPC Class Codes: H01L 33/60 Reflective elements

Abstract

An inorganic light-emitting diode structure includes a transparent substrate and an inorganic semiconductor having a conduction layer and a light-emitting layer over and in contact with only a portion of the conduction layer. A first metal contact is in electrical contact with the conduction layer and a second metal contact is in electrical contact with a second contact portion of the light-emitting layer so that a current supplied between the first metal contact and the second metal contact through the inorganic semiconductor causes the light-emitting layer to emit light. A dielectric layer is located over at least a portion of the light-emitting layer and a reflective layer is located over at least a portion of the dielectric layer. The reflective layer encapsulates the light-emitting layer exclusive of the portion of the conduction layer in contact with the light-emitting layer.

Claims

1. An inorganic light-emitting diode structure, comprising:

a transparent substrate; and

two or more inorganic semiconductors, each formed in a three-dimensional structure adhered to a common side of the transparent substrate, each three-dimensional structure comprising;

a conduction layer;

a light-emitting layer disposed on the conduction layer, the light-emitting layer and the conduction layer each having first and second opposing sides, wherein a portion of the first side of the conduction layer is in contact with the second side of the light-emitting layer and the transparent substrate is adjacent to the second side of the conduction layer;

a first metal contact in electrical contact with a first contact portion of the first side of the conduction layer;

an electrode comprising a second metal contact in electrical contact with a second contact portion of the first side of the light-emitting layer so that a current supplied between the first metal contact and the second metal contact through the inorganic semiconductor causes the light-emitting layer to emit light;

a dielectric layer disposed on at least a portion of the light-emitting layer; and

a reflective layer having one or more portions disposed on at least a portion of the dielectric layer, the reflective layer surrounding the light-emitting layer exclusive of the portion of the conduction layer in contact with the light-emitting layer, wherein;

the one or more portions of the reflective layer comprises the electrode, and

the dielectric layer and the electrode are in direct contact with the transparent substrate only on the common side on which the three-dimensional structures are disposed.

2. The inorganic light-emitting diode structure of claim 1, wherein the reflective layer is at least partially in contact with the dielectric layer.

3. The inorganic light-emitting diode structure of claim 1, wherein the reflective layer comprises first and second portions and the first portion of the reflective layer is in electrical contact with the first metal contact.

4. The inorganic light-emitting diode structure of claim 1, wherein the reflective layer comprises first and second portions and the second portion of the reflective layer is in electrical contact with the second metal contact and the second portion of the reflective layer forms an electrode.

5. The inorganic light-emitting diode structure of claim 1, wherein the reflective layer comprises first, second, and third portions, the first portion of the reflective layer is in electrical contact with the first metal contact, the second portion of the reflective layer is in electrical contact with the second metal contact, the first and second portions of the reflective layer are separated by a gap located adjacent to the first side of the light-emitting layer, and the third portion of the reflective layer is electrically isolated from the first and second portions of the reflective layer and is located on a side of the gap opposite the first side of the light-emitting layer.

6. The inorganic light-emitting diode structure of claim 5, comprising another dielectric layer located between and in contact with the third portion of the reflective layer and the first and second portions of the reflective layer.

7. The inorganic light-emitting diode structure of claim 1, wherein the reflective layer comprises first and second portions, the first portion of the reflective layer is in electrical contact with the first metal contact, the second portion of the reflective layer is in electrical contact with the second metal contact, and the first and second portions of the reflective layer are separated by a gap located adjacent to the first side of the conduction layer.

8. The inorganic light-emitting diode structure of claim 7, comprising a third portion of the reflective layer that is electrically isolated from the first and second portions of the reflective layer and is located on a side of the gap opposite the first side of the conduction layer.

9. The inorganic light-emitting diode structure of claim 8, comprising another dielectric layer located between the third portion of the reflective layer and the first and second portions of the reflective layer.

10. The inorganic light-emitting diode structure of claim 1, wherein the reflective layer is an electrically conductive layer.

11. The inorganic light-emitting diode structure of claim 1, wherein the reflective layer is a reflective metal layer.

12. The inorganic light-emitting diode structure of claim 1, wherein the inorganic light-emitting diode structure has at least one of a width, length, and height from 2 to 5 μ

m, 5 to 10 μ

m, 10 to 20 μ

m, or 20 to 50 μ

m.

13. The inorganic light-emitting diode structure of claim 1, wherein the first metal contacts of the two or more inorganic semiconductors are electrically connected in common or the second metal contacts of the two or more inorganic light-emitting diode structures are electrically connected in common.

14. The inorganic light-emitting diode structure of claim 1, wherein the two or more semiconductors structures on the common transparent substrate forms a display.

15. The inorganic light-emitting diode structure of claim 1, wherein different ones of the two or more semiconductors structures emit different colors of light.

16. The inorganic light-emitting diode structure of claim 15, wherein the different ones of the two or more inorganic semiconductors comprise different inorganic semiconductor materials.

17. The multi inorganic light-emitting diode structure of claim 1, wherein the two or more inorganic semiconductors are grouped into pixels, each pixel having two or more different inorganic semiconductor materials that emit different colors of light.

18. The inorganic light-emitting diode structure of claim 17, wherein each pixel has three or more different inorganic semiconductors that emit at least red, green, and blue.

19. The inorganic light-emitting diode structure of claim 17, wherein inorganic light-emitting diode structures within each pixel group are spatially closer together than inorganic light-emitting diode structures of another pixel group.

20. The inorganic light-emitting diode structure of claim 1, wherein the inorganic semiconductor structure has at least one of a width, length, and height from 2 to 5 μ

m, 5 to 10 μ

m, 10 to 20 μ

m, or 20 to 50 μ

m.

21. The inorganic light-emitting diode structure of claim 1, wherein the transparent substrate is a glass, a polymer, or a plastic.

22. An inorganic light-emitting diode structure, comprising:

a transparent substrate; and

two or more inorganic semiconductors, each formed in a three-dimensional structure adhered to a common side of the transparent substrate, each three-dimensional structure comprising;

a conduction layer,

a light-emitting layer disposed on the conduction layer, the light-emitting layer and the conduction layer each having first and second opposing sides, wherein only a portion of the first side of the conduction layer is in contact with the second side of the light-emitting layer and the transparent substrate is adjacent to the second side of the conduction layer;

a first metal contact in electrical contact with a first contact portion of the first side of the conduction layer;

an electrode comprising a second metal contact in electrical contact with a second contact portion of the first side of the light-emitting layer so that a current supplied between the first metal contact and the second metal contact through the inorganic semiconductor causes the light-emitting layer to emit light;

a dielectric layer located over at least a portion of the light-emitting layer; and

a reflective layer having one or more portions located over at least a portion of the dielectric layer, the reflective layer surrounding the light-emitting layer exclusive of the portion of the conduction layer in contact with the light-emitting layer, wherein the first and second metal contacts are electrically separate and are spatially separated by a gap over the first side of the conduction layer and not over the light-emitting layer, wherein;

the one or more portions of the reflective layer comprises the electrode, and

the dielectric layer and the electrode are in direct contact with the transparent substrate only on the common side on which the three-dimensional structures are disposed.

23. An inorganic light-emitting diode structure, comprising:

a transparent substrate; and

two or more inorganic semiconductors, each formed in a three-dimensional structure adhered to a common side of the substrate, each three-dimensional structure comprising;

a conduction layer,

a light-emitting layer disposed on the conduction layer, the light-emitting layer and the conduction layer each having first and second opposing sides, wherein only a portion of the first side of the conduction layer is in contact with the second side of the light-emitting layer and the substrate is adjacent to the second side of the conduction layer, wherein the conduction layer comprises a first contact portion on the first side of the conduction layer and the light-emitting layer comprises a second contact portion on the first side of the light-emitting layer such that a current supplied between the first contact portion and the second contact portion through the inorganic semiconductor causes the light-emitting layer to emit light;

a dielectric layer disposed on at least a portion of the light-emitting layer; and

a reflective layer having one or more portions disposed on at least a portion of the dielectric layer, the reflective layer surrounding the light-emitting layer exclusive of the portion of the conduction layer in contact with the light-emitting layer, wherein the dielectric layer is in direct contact with the transparent substrate only on the common side on which the three-dimensional structures are disposed.

24. The inorganic light-emitting diode structure of claim 23, wherein the first contact portion is in electrical contact with a first metal contact and the second contact portion is in contact with an electrode comprising a second metal contact, wherein:

the one or more portions of the reflective layer comprises the electrode, and

the electrode is in contact with the transparent substrate only on the side on which the three-dimensional structures are disposed.

25. An inorganic light-emitting diode structure, comprising:

a transparent substrate;

two or more inorganic semiconductors, each comprising;

a conduction layer;

a light-emitting layer disposed on a portion of the conduction layer;

a first metal contact in electrical contact with the conduction layer; and

an electrode comprising a second metal contact in electrical contact with a second contact portion of the light-emitting layer so that a current supplied between the first metal contact and the second metal contact through the inorganic semiconductor causes the light-emitting layer to emit light;

a dielectric layer disposed on at least a portion of the light-emitting layer; and

a reflective layer having one or more portions disposed on at least a portion of the dielectric layer, the reflective layer surrounding the light-emitting layer exclusive of the portion of the conduction layer in contact with the light-emitting layer, wherein;

the one or more portions of the reflective layer comprises the electrode, and

the dielectric layer and the electrode are in direct contact with the transparent substrate only on the side on which the three-dimensional structures are disposed.