Energy transfer based emission analysis of Dy3+/Eu3+ co-doped ZANP glasses for white LED applications

The results presented here are on the photoluminescence properties of different concentrations of Eu3+ in a 0.5 mol% Dy3+ doped zinc-aluminium-sodium-phosphate (ZANP) glasses. Under UV-light excitation the 0.5 mol% ZANP glass show a yellowish white light emission and in order to obtain white light emission, the Dy3+/Eu3+ co-doped ZANP glasses with fixed Dy3+ concentration (0.5 mol%) and varied Eu3+ concentration (0.1-1.5 mol%) were synthesized. The energy transfer phenomenon between Dy3+ and Eu3+ ions was studied based from the emission spectra with different excitation wavelengths and the decay curves of the F-4(9/2) level of Dy3+ ion. The energy transfer efficiency (eta) and energy transfer probabilities (P-da) are calculated for Dy3+/Eu3+ co-doped ZANP glasses. The energy transfer probabilities are linear with the acceptor (Eu3+) concentration confirming the fact that the dipoleedipole interaction is responsible for the energy transfer (ET) process of Dy3+ -> Eu3+ ion. The chromaticity co-ordinates were calculated from emission spectra of Dy3+/Eu3+ co-doped ZANP glasses with different excitation wavelengths. These results show that the white light has been achieved by exciting Dy3+/Eu3+ co-doped ZANP glass with ultraviolet or blue light. (C) 2015 Elsevier B.V. All rights reserved.