title: Eu2+-activated silicon-oxynitride Ca3Si2O4N2: a green-emitting phosphor for white LEDs.
abstract: 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.
authors.affiliation: 1Material and Chemical Research Laboratories, ITRI, Hsinchu 300, Taiwan. marmaidtw@itri.org.tw
authors.forename: Yi-Chen
authors.initials: YC
authors.lastname: Chiu
authors.forename: Chien-Hao
authors.initials: CH
authors.lastname: Huang
authors.forename: Te-Ju
authors.initials: TJ
authors.lastname: Lee
authors.forename: Wei-Ren
authors.initials: WR
authors.lastname: Liu
authors.forename: Yao-Tsung
authors.initials: YT
authors.lastname: Yeh
authors.forename: Shyue-Ming
authors.initials: SM
authors.lastname: Jang
authors.forename: Ru-Shi
authors.initials: RS
authors.lastname: Liu