(INVITED)KRbAl2B2O7: Eu2+: A new blue-emitting luminescent material with good thermal stability

Abstract

Exploring new efficient phosphor for lighting has always been a worthwhile and necessary work. Herein, we develop a new blue-emitting luminescent material KRbAl2B2O7:Eu2+ through the solid-state method. Under n-UV excitation, this phosphor can emit blue light peaking at 450 nm with FWHM about 55 nm. It owns a broad excitation spectrum covering from 250 nm to 425 nm. Two luminescent centers were identified through the analysis of crystal structure and decay times. Furthermore, the phosphor shows high thermal stability and the emission intensity remains about 81% at 425 K of that at room temperature. The thermal quenching is mainly attributed to the increase of non-radiative transition and thermally activated phonon-assisted tunneling effect at high temperature. By employing as-prepared material as blue phosphor, the fabricated white LED device can emit white light with high CRI (Ra = 85.6) and low CCT (4236 K). These results illustrate that the possibility of KRbAl2B2O7 as a blue-emitting phosphor for practical application.