Gas Phase Enhancement of Emission Color Quality in Solid State LEDs

• US 20150053916A1
• Filed: 08/20/2014
• Published: 02/26/2015
• Est. Priority Date: 08/22/2013
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Nanoco Technologies Limited (Nanoco Group Plc)
• Inventors: Pickett, Nigel, Gresty, Nathalie
• Granted Patent: US 9,574,135 B2
• Time in Patent Office: Days
• US Class Current: 257/13
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: B82Y 40/00 Manufacture or treatment of nanostructures
• CPC Class Codes: C01B 19/007 Tellurides or selenides of metals C01B19/002 takes precedence
• CPC Class Codes: C01B 25/082 of boron, aluminium, gallium or indium
• CPC Class Codes: C01B 25/087 of gallium or indium
• CPC Class Codes: C01G 11/02 Sulfides
• CPC Class Codes: C01G 9/08 Sulfides
• CPC Class Codes: C01P 2002/84 by UV- or VIS- data
• CPC Class Codes: C01P 2004/64 Nanometer sized, i.e. from 1-100 nanometer
• CPC Class Codes: C01P 2006/60 Optical properties, e.g. expressed in CIELAB-values
• CPC Class Codes: C09K 11/02 Use of particular materials as binders, particle coatings or suspension media therefor
• CPC Class Codes: C09K 11/565 with zinc cadmium
• CPC Class Codes: C09K 11/70 containing phosphorus
• CPC Class Codes: C09K 11/883 with zinc or cadmium
• CPC Class Codes: H01L 33/002 having heterojunctions or graded gap
• CPC Class Codes: H01L 33/0087 with a substrate not being a II-VI compound
• CPC Class Codes: H01L 33/06 within the light emitting region, e.g. quantum confinement structure or tunnel barrier
• CPC Class Codes: H01L 33/08 with a plurality of light emitting regions, e.g. laterally discontinuous light emitting layer or photoluminescent region integrated within the semiconductor body H01L27/15 takes precedence
• CPC Class Codes: H01L 33/28 containing only elements of Group II and Group VI of the Periodic Table
• CPC Class Codes: H01L 33/30 containing only elements of Group III and Group V of the Periodic Table
• CPC Class Codes: H01L 33/32 : containing nitrogen
• CPC Class Codes: Y10S 977/774 : Exhibiting three-dimensional carrier confinement, e.g. quantum dots
• CPC Class Codes: Y10S 977/891 : Vapor phase deposition
• CPC Class Codes: Y10S 977/95 : Electromagnetic energy

Abstract

Light-emitting materials are made from a porous light-emitting semiconductor having quantum dots (QDs) disposed within the pores. According to some embodiments, the QDs have diameters that are essentially equal in size to the width of the pores. The QDs are formed in the pores by exposing the porous semiconductor to gaseous QD precursor compounds, which react within the pores to yield QDs. According to certain embodiments, the pore size limits the size of the QDs produced by the gas-phase reactions. The QDs absorb light emitted by the light-emitting semiconductor material and reemit light at a longer wavelength than the absorbed light, thereby “down-converting” light from the semiconductor material.

Claims

1. A composition comprising:

a light-emitting semiconductor material having pores therein; and

quantum dots (QDs) disposed within the pores;

wherein the composition is free of solvent.

2. The composition of claim 1, wherein the pores are about 2 nm to about 10 nm in diameter.

3. The composition of claim 1, wherein the light-emitting semiconductor material comprises as GaN, AlGaAs, AlGaInP, or AlGaInN, or any derivatives thereof.

4. The composition of claim 1, wherein the QDs comprise a semiconductor material selected from CdS, CdSe, ZnS, ZnSe InP, GaP Cd₃P₂ and In₂Se₃.

5. The composition of claim 1, wherein the QDs have diameters essentially equal to the diameters of the pores.

6. The composition of claim 1, wherein the QDs emit green light when illuminated by light from the light-emitting semiconductor.

7. The composition of claim 1, wherein the QDs emit red light when illuminated by light from the light-emitting semiconductor.

8. A light emitting device, comprising:

a light-emitting semiconductor material having pores therein; and

quantum dots (QDs) disposed within the pores;

wherein the composition is free of solvent.

9. The device of claim 8, wherein the pores are about 2 nm to about 10 nm in diameter.

10. The device of claim 8, wherein the light-emitting semiconductor material comprises as GaN, AlGaAs, AlGaInP, or AlGaInN, or any derivatives thereof.

11. The device of claim 8, wherein the QDs comprise a semiconductor material selected from CdS, CdSe, ZnS, ZnSe InP, GaP Cd₃P₂ and In₂Se₃.

12. The device of claim 8, wherein the QDs emit green light when illuminated by light from the light-emitting semiconductor.

13. A method for synthesizing QDs in a light-emitting semiconductor material, the method comprising:

flowing gaseous QD precursors through pores in a semiconductor material to effect reaction of the QD precursors in the absence of liquid solvent.

14. The method of claim 13, wherein the pores are about 2 nm to about 10 nm in diameter.

15. The method of claim 13, wherein the light-emitting semiconductor material comprises as GaN, AlGaAs, AlGaInP, or AlGaInN, or any derivatives thereof.

16. The method of claim 13, wherein the QDs comprise a semiconductor material selected from CdS, CdSe, ZnS, ZnSe InP, GaP Cd₃P₂ and In₂Se₃.

17. The method of claim 13, wherein the QDs have diameters essentially equal to the diameters of the pores.