Photoluminescence of BaZrSi3O9:Bi3+ as a yellow emitting phosphor for White LEDs

A yellow-emitting phosphor, BaZrSi3O9:Bi3+, was synthesized in air via solid state reaction method. Luminescence properties of this phosphor were examined by steady-state and time-resolved as well as temperature-dependent luminescence spectra. The obtained BaZrSi3O9:Bi3+ sample shows strong absorption in 300-400 nm, and gives bright and broad yellow emission centered at 560 nm upon 350 nm excitation. The broad emission is originated from P-3(1) -> S-1(0) transition of Bi3+, which has a lifetime around similar to 1 mu s in BaZrSi3O9. Upon heating in the temperature range from room temperature to 250 degrees C, accompanied by the emission intensity deceases (emission intensity at 150 degrees C retains 76% its initial intensity at room temperature), the emission of Bi3+ in BaZrSi3O9 is blue-shifted, which is ascribed to the thermally active phonon-assisted tunneling from the lower energy to the higher energy emission band in the excited states of Bi3+. (C) 2016 Elsevier Ltd. All rights reserved.