Concentration quenching of Eu2+ in a thermal-stable yellow phosphor Ca2BO3Cl:Eu2+ for LED application

A piece-shaped phosphor Ca2BO3Cl: Eu2+ was synthesized by solid-state reaction method. This phosphor exhibited wide absorption in ultra-violet and visible range, and bright yellow emission band centering at 570 nm. The concentration quenching mechanism was verified to be a dipole-dipole interaction, and its critical transfer distance was about 17 angstrom by both calculated crystal structural method and experimental spectral method. This phosphor has a good thermal stability with a quenching temperature (T-1/2) of 200 degrees C. Yellow and white LEDs were fabricated with this phosphor and near UV chips, and the yellow LED has a high color purity of 97.0% and promising current tolerant property, while the white LED shows a luminous efficiency of 11.68 lm/W. Crown Copyright (C) 2011 Published by Elsevier B.V. All rights reserved.