Title: High color rendering white light-emitting-diode illuminator using the red-emitting Eu(2+)-activated CaZnOS phosphors excited by blue LED
Authors: Kuo, Te-Wen
Liu, Wei-Ren
Chen, Teng-Ming
Department of Applied Chemistry
Issue Date: 12-Apr-2010
Abstract: A red phosphor CaZnOS:Eu(2+) was synthesized by solid state reaction and has been evaluated as a candidate for white LEDs. For this material, the XRD, PL, PL excitation (PLE) and diffuse reflection spectra have also been investigated. CaZnOS:Eu(2+) reveals a broad absorption band and good color purity. By utilizing a mixture of red-emitting CaZnOS:Eu(2+), green-emitting (Ba,Sr)(2)SiO(4):Eu(2+) and yellow-emitting Y(3)Al(5)O(12):Ce(3+) as light converters, an intense white InGaN-based blue-LED (similar to 460 nm) was fabricated to exhibit a high color-rendering index Ra of 85 at a correlated color temperature of 4870 K. Based on the results, we are currently evaluating the potential application of CaZnOS:Eu(2+) as a red-emitting blue-chip convertible phosphor. (c) 2010 Optical Society of America
URI: http://hdl.handle.net/11536/5518
ISSN: 1094-4087
Volume: 18
Issue: 8
Begin Page: 8187
End Page: 8192
Appears in Collections:Articles