Open AccessEu^2+-activated silicon-oxynitride Ca_3Si_2O_4N_2: a green-emitting phosphor for white LEDs
Author(s) -
YiChen Chiu,
ChienHao Huang,
Te-Ju Lee,
Weiren Liu,
YaoTsung Yeh,
ShyueMing Jang,
RuShi Liu
Publication year - 2011
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.19.00a331
Subject(s) - phosphor , materials science , color rendering index , light emitting diode , luminescence , color temperature , doping , green light , photoluminescence , optoelectronics , diffuse reflection , silicon , diode , analytical chemistry (journal) , optics , chemistry , blue light , physics , chromatography
The green-emitting phosphor Ca3Si2O4N2:Eu2+ was synthesized using a solid-state reaction. The luminescence properties, diffuse reflection spectrum, and thermal quenching were firstly studied, and a white light-emitting diode (wLED) was fabricated using the Eu2+-activated Ca3Si2O4N2 phosphor. Eu2+-doped Ca3Si2O4N2 exhibited a broad green emission band centered between 510 and 550 nm depending on the concentration of Eu2+. The optimal doping concentration of Eu2+ in Ca3Si2O4N2 was 1 mol%. The energy transfer between Eu2+ ions proceeds by an electric multipolar interaction mechanism, with a critical transfer distance of approximately 30.08 Å. A wLED with an color-rendering index Ra of 88.25 at a correlated color temperature of 6029 K was obtained by combining a GaN-based n-UV LED (380 nm) with the blue-emitting BaMgAl10O17:Eu2+, green-emitting Ca3Si2O4N2:Eu2+, and red-emitting CaAlSiN3:Eu2+ phosphors. The results present Ca3Si2O4N2:Eu2+ as an attractive candidate for use as a conversion phosphor for wLED applications.