Solid state white light emitter and display using same

• US 8,659,034 B2
• Filed: 03/12/2013
• Issued: 02/25/2014
• Est. Priority Date: 03/26/1996
• Status: Expired due to Fees

• Current Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Baretz, Bruce, Tischler, Michael A.
• Primary Examiner(s): Trinh, Hoa (Vikki) B
• Application Number:
  US13/798,019
• Publication Number:
  US 20130207132A1
• Time in Patent Office: 350 Days
• Field of Search: 257/98, 257/99, 257/100, 257/88, 257/79
• US Class Current: 257/79
• CPC Class Codes: G09F 13/04 Signs, boards or panels, illuminated from behind the insignia
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48137 the bodies being arranged next to each other, e.g. on a common substrate
• CPC Class Codes: H01L 2224/48139 with an intermediate bond, e.g. continuous wire daisy chain
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• 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 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 33/50 Wavelength conversion elements
• CPC Class Codes: H01L 33/504 Elements with two or more wavelength conversion materials
• CPC Class Codes: Y02E 10/52 PV systems with concentrators

Abstract

A light emitting assembly comprising a solid state device coupleable with a power supply constructed and arranged to power the solid state device to emit from the solid state device a first, relatively shorter wavelength radiation, and a down-converting luminophoric medium arranged in receiving relationship to said first, relatively shorter wavelength radiation, and which in exposure to said first, relatively shorter wavelength radiation, is excited to responsively emit second, relatively longer wavelength radiation. In a specific embodiment, monochromatic blue or UV light output from a light-emitting diode is down-converted to white light by packaging the diode with fluorescent organic and/or inorganic fluorescers and phosphors in a polymeric matrix.

Claims

1. A white light LED, comprising a gallium nitride based semiconductor LED die configured to emit blue light primary radiation, said LED die being packaged with phosphor or fluorescer in a polymer, wherein the phosphor or fluorescer is configured to interact with the blue light primary radiation to produce a secondary emission down-converted light, and wherein the blue light primary radiation and said down-converted light produce a white light output, said gallium nitride based semiconductor LED die comprising indium, and said phosphor or fluorescer being dispersed in said polymer.

2. The white light LED of claim 1, wherein the gallium nitride based semiconductor LED die further comprises aluminum.

3. The white light LED of claim 1, wherein the phosphor or fluorescer comprises inorganic phosphor or fluorescer.

4. The white light LED of claim 1, wherein the down-converted light from the phosphor or fluorescer comprises yellow emission.

5. The white light LED of claim 1, wherein the down-converted light from the phosphor or fluorescer comprises red emission.

6. The white light LED of claim 1, wherein the phosphor or fluorescer comprises multiple phosphor or fluorescer materials.

7. The white light LED of claim 1, in a display.

8. The white light LED of claim 7, wherein the display comprises a liquid crystal display.

9. The white light LED of claim 1, in a back-lighting array.

10. The white light LED of claim 1, wherein the white light output comprises at least one of primary and secondary blue emission.