Nitride-Based Red-Emitting Phosphors in RGB (Red-Green-Blue) Lighting Systems

• US 20150315464A1
• Filed: 02/10/2015
• Published: 11/05/2015
• Est. Priority Date: 05/19/2008
• Status: Abandoned Application

• Current Assignee: Intematix Corporation
• Original Assignee: Intematix Corporation
• Inventors: Liu, Shengfeng, Tao, Dejie, Yuan, Xianglong, Li, Yi-Qun
• Application Number:
  US14/618,207
• Publication Number:
  US 20150315464A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: C04B 2235/3206 Magnesium oxides or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3208 Calcium oxide or oxide-forming salts thereof, e.g. lime
• CPC Class Codes: C04B 2235/3213 Strontium oxides or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3215 Barium oxides or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3217 Aluminum oxide or oxide forming salts thereof, e.g. bauxite, alpha-alumina
• CPC Class Codes: C04B 2235/3224 Rare earth oxide or oxide forming salts thereof, e.g. scandium oxide
• CPC Class Codes: C04B 2235/3286 Gallium oxides, gallates, indium oxides, indates, thallium oxides, thallates or oxide forming salts thereof, e.g. zinc gallate
• CPC Class Codes: C04B 2235/3409 Boron oxide, borates, boric acids, or oxide forming salts thereof, e.g. borax
• CPC Class Codes: C04B 2235/3852 Nitrides, e.g. oxynitrides, carbonitrides, oxycarbonitrides, lithium nitride, magnesium nitride
• CPC Class Codes: C04B 2235/3865 Aluminium nitrides
• CPC Class Codes: C04B 2235/3873 Silicon nitrides, e.g. silicon carbonitride, silicon oxynitride
• CPC Class Codes: C04B 2235/3895 Non-oxides with a defined oxygen content, e.g. SiOC, TiON
• CPC Class Codes: C04B 2235/444 Halide containing anions, e.g. bromide, iodate, chlorite
• CPC Class Codes: C04B 2235/445 Fluoride containing anions, e.g. fluosilicate
• CPC Class Codes: C04B 2235/723 Oxygen content
• CPC Class Codes: C04B 35/58 based on borides, nitrides, i.e. nitrides, oxynitrides, carbonitrides or oxycarbonitrides or silicides containing free binder metal C22C29/00
• CPC Class Codes: C04B 35/581 based on aluminium nitride
• CPC Class Codes: C04B 35/584 based on silicon nitride
• CPC Class Codes: C09K 11/0883 Arsenides; Nitrides; Phosphides
• CPC Class Codes: C09K 11/77348 Silicon Aluminium Nitrides or Silicon Aluminium Oxynitrides
• CPC Class Codes: F21Y 2115/10 : Light-emitting diodes [LED]
• CPC Class Codes: H05B 33/12 : Light sources with substantially two-dimensional radiating surfaces
• CPC Class Codes: Y02B 20/00 : Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps

Abstract

Embodiments of the present invention are directed to nitride-based, red-emitting phosphors in red, green, and blue (RGB) lighting systems, which in turn may be used in backlighting displays and warm white-light applications. In particular embodiments, the red-emitting phosphor is based on CaAlSiN₃ type compounds activated with divalent europium. In one embodiment, the nitride-based, red emitting compound contains a solid solution of calcium and strontium compounds (Ca,Sr)AlSiN₃:Eu²⁺, wherein the impurity oxygen content is less than about 2 percent by weight. In another embodiment, the (Ca,Sr)AlSiN₃:Eu²⁺ compounds further contains a halogen in an amount ranging from about zero to about 2 atomic percent, where the halogen may be fluorine (F), chlorine (Cl), or any combination thereof. In one embodiment at least half of the halogen is distributed on 2-fold coordinated nitrogen (N2) sites relative to 3-fold coordinated nitrogen (N3) sites.

Claims

1. A nitride-based, red emitting compound of the type (Ca,Sr)AlSiN₃:

Eu²⁺, wherein the impurity oxygen content is less than about 2 percent by weight.

5. An RGB lighting system for use in a white LED or backlighting display application, the RGB lighting system comprising:

the nitride-based, red-emitting phosphor according to claim 1,

a green phosphor, and

a blue LED emitting in a wavelength ranging from about 400 nm to about 550 nm.

2. A nitride-based, red emitting compound of the type (Ca,Sr)AlSiN₃:

Eu²⁺, further comprising a halogen whose content ranges from greater than about zero to about 2 atomic percent.

3. The compound of claim 2, wherein the halogen is selected from the group consisting of F and Cl.

4. The compound of claim 2, wherein at least half of the halogen is distributed on 2-fold coordinated nitrogen (N2) sites relative to 3-fold coordinated nitrogen (N3) sites.

6. An RGB lighting system for use in a white LED or backlighting display application, the RGB lighting system comprising:

the nitride-based, red-emitting phosphor according to claim 2,

a green phosphor, and

a blue LED emitting in a wavelength ranging from about 400 nm to about 550 nm.