(Ba,Sr)Y(2)Si(2)Al(2)O(2)N(5):Eu(2+): a novel near-ultraviolet converting green phosphor for white light-emitting diodes

Abstract

A highly intense green-emitting phosphor BaY(2)Si(2)Al(2)O(2)N(5) : Eu(2+) (BYN : Eu(2+)) peaking at 511 nm was synthesized by a solid state reaction. The structure refinement, luminescence properties of BYN : Eu(2+) phosphors as well as their thermal quenching and the fabrication of white-light-emitting diodes (W-LEDs) were firstly investigated. By partially substituting Ba by Sr, namely (Ba, Sr)Y(2)Si(2)Al(2)O(2)N(5) : Eu(2+) (BSYN : Eu(2+)), the emission peak was shifted to 565 nm, giving a yellow-orange color, due to the splitting of the 5d energy level. By utilizing a mixture of blue-emitting BaMgAl(10)O(17) : Eu(2+), green-emitting BYN : Eu(2+) and red-emitting CaAlSiN(3) : Eu(2+) phosphors as light converters, an intense white GaN-based n-UV-LED (380 nm) was fabricated to a exhibit good color-rendering index R(a) of 84.5 at a correlated color temperature of 5089 K and CIE coordinates of (0.3425, 0.3478). Based on these results, we are currently evaluating the potential application of BYN : Eu(2+) as a green-emitting near-UV convertible phosphor.