Light emitting diode with nanoparticles

• US 6,838,816 B2
• Filed: 06/03/2002
• Issued: 01/04/2005
• Est. Priority Date: 05/28/2002
• Status: Active Grant

• Current Assignee: Transpacific IP Group Limited
• Original Assignee: National Taiwan University (Government of The Republic of China)
• Inventors: Lin, Ching-Fuh, Su, Wei-Fang
• Primary Examiner(s): Philogene, Haissa
• Application Number:
  US10/159,255
• Publication Number:
  US 20030222572A1
• Time in Patent Office: 946 Days
• Field of Search: 313/506, 313/505, 313/503, 313/498, 313/499, 445/50, 445/51, 362/800, 257/103, 257/40, 257/613, 257/82
• US Class Current: 313/499
• 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: Y10S 362/80 Light emitting diode

Abstract

The present invention discloses a simple, low cost method to fabricate light emitting source using luminescent colloid nanoparticles. It uses monodispersed colloid light emitting nanoparticles of oxides, semiconductors, and polymers to fabricate high quality, narrow bandwidth light emitting source. The colloid particles can be dispersed homogeneously in liquid that can be coated easily on a substrate using a simple coating method such as spray, dip coating or spin coating. There is no restriction on the size or shape of the substrate. Therefore, a low cost, large area, high efficiency and reproducible light emitting source can be made easily.

Claims

1. A light emitting diode (LED) with luminescent nanoparticles comprising:

a) a substrate;

b) one colloid luminescent nanoparticles layer grown on a first surface of the substrate;

c) a first electrode formed on a second surface of the substrate; and

d) a second electrode formed on the luminescent nanoparticles layer, wherein the colloid luminescent nanoparticles layer emits a light when a current flows between the first and second electrodes, the LED having light emitting spectra tunable between 526 nm and 57 nm and a turn on voltage of 3V.

2. The LED according to claim 1, wherein said luminescent nanoparticles layer is an oxide luminescent nanoparticles layer.

3. The LED according to claim 1, wherein said luminescent nanoparticles layer is a semiconductor luminescent nanoparticles layer.

4. The LED according to claim 1, wherein said luminescent nanoparticles layer is a macromolecule luminescent nanoparticles layer.

5. The LED according to claim 3, wherein said luminescent nanoparticles layer is a CDs nanoparticles layer.

6. The LED according to claim 1, each luminescent nanoparticle of said luminescent nanoparticles layer has a specific diameter between 5 nm to and 500 nm.

7. The LED according to claim 1, wherein the colloid luminescent nanoparticles layer has a uniform thickness.

8. The LED according to claim 1, wherein said substrate is a semiconductor substrate.

9. The LED according to claim 1, wherein said substrate is an insulator substrate.

10. The LED according to claim 8, wherein said substrate is a silicon substrate.

11. The LED according to claim 1, wherein said first electrode is comprised of a material selected from a group consisting of Au, Ag, Al, and Mg.

12. The LED according to claim 1, wherein said second electrode is comprised of a material selected from a group consisting of Au, Ag, Al, and Mg.