CaScAlSiO sub(6):Eu super(2+): A novel near-ultraviolet converting blue-emitting phosphor for white light-emitting diodes

A high intense blue-emitting phosphor CaScAlSiO sub(6):Eu super(2+) (CSAS:Eu super(2+)) peaking at 430-460 nm was synthesized by solid state reactions. The luminescence properties of CSAS:Eu super(2+) phosphors as well as thermal quenching and the fabrication of white-light-emitting diodes (W-LEDs) were firstly investigated. The optimal doping concentration of Eu super(2+) is 2 mol% and the critical distance for energy transfer is determined to be 19.49 Aa. By utilizing a mixture of blue-emitting CSAS:Eu super(2+), green-emitting SrSi sub(2)O sub(2)N sub(2):Eu super(2+) and red-emitting CaAlSiN sub(3):Eu super(2+) phosphors as light converters, an intense white GaN-based n-UV-LED (370 nm) was fabricated to exhibit good color-rendering index R sub(a) of as high as 87.98 at correlated color temperature of 5537 K and CIE coordinates of (0.33, 0.42). Based on the results, we are currently evaluating the potential application of CSAS:Eu super(2+) as a blue-emitting near-UV convertible phosphor.