Orange-yellow phosphor and warm white LED using the same

US8029699B2 · kind B2 · utility

Assignee

• Wei-Hung Lo · TW

Inventors

• Soshchin Naum · Changhua City, TW
• Wei-Hung Lo · Taipei, TW
• Chi-Ruei Tsai · Taipei, TW

Key dates

• Filing date: Feb 7, 2008
• Grant date: Oct 4, 2011
• Expiry date: Mar 12, 2029

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T428/2993
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

A phosphor providing orange-yellow radiation is prepared from a cerium activated rare-earth garnet substrate that contains Li (lithium), Si (silicon), N (nitrogen) and F (fluorine) atoms, obtaining the overall stoichiometric equation of (ΣLn)3Al5-x-yLiy/3Mgx/2Si(x/2+2y/3)Fq/2O12-qNq/2. When the activating wavelength is 440˜475 nm, the orange sub-energy band becomes 542˜590 nm, and the radiation quatum ouput q>0.9, showing a cubic crystal garnet structure. The phosphor has color coordinate Σ(x+y)≧0.89, and color purity α≧0.89. The invention also provides a warm white LED that has light intensity J≧300 cd, half open angle 2θ≧60°, luminous efficiency 65≦ζ≦100 lm/W, and color temperature within 2800≦T≦5500K.