Eu2+, Ce3+ Luminescence and Ce3+ -> Eu2+ Energy-Transfer Studies on Sr2LiSiO4F: A White Light-Emitting Phosphor

Abstract

Eu2+ luminescence is studied in Sr2LiSiO4F, and the emission spectrum shows an intense and broad green emission band with two peak maxima (475 and 505 nm). The two emission bands are due to Eu2+ present in the two crystallographic distinct Sr sites in the host lattice. Ce3+ luminescence is studied in Sr2LiSiO4F and shows a broad and bright blue emission band at around 430 nm under 350 nm excitation. The effect of Ce3+ co-doping is studied in Sr2LiSiO4F:Eu2+ phosphor. Thus, the co-doping of Ce3+ also enhances the absorption of Eu2+ in the near-UV region, where the light-emitting diode emission occurs. Ce3+ co-doped samples show broad-band emission ranging from 360 to 620 nm (blue to green-yellow), which results in white emission. This indicates partial energy transfer from Ce3+ to Eu2+. Selected compositions of this phosphor material can find potential application in solid-state lighting. (C) 2009 The Electrochemical Society. [DOI: 10.1149/1.3122663] All rights reserved.