Origin of White Luminescence in Ag-Eu Co-doped Oxyfluoride Glasses

A combination of red, green and blue emissions has emerged to achieve pure white emission (X = 0.323, Y = 0.320) in Ag-Eu co-doped oxyfluoride glasses. The type of luminescent species, the origin of white emission and the enhancement mechanism for red and blue emissions were investigated by means of absorption, emission and excitation spectra, decay lifetime measurements, as well as time-resolved spectroscopy. Results prove that white emission is originated from f-f transitions of Eu(3+) (red), ML-Ag (very small molecule-like, non-plasmonic Ag particles, green) and 5d-4f transition of Eu(2+) (blue). Our researches show that Ag-Eu co-doped glasses may provide a new platform to design and fabricate novel phosphors for ultraviolet light-emitting diode (LED) chips. (C) 2011 The Electrochemical Society. [DOI: 10.1149/1.3568950] All rights reserved.