White light emission and bidirectional energy transfer in an Eu~(3+)/Tb~(3+) co-doped NaLa(WO_4)_2 phosphor

摘要

Eu3+/Tb3+ co-doped NaLa(WO4)(2) phosphor was synthesized by a hydrothermal process. The structure of the samples were investigated by X-ray diffraction. The photoluminescence spectra, photoluminescence excitation spectra, and fluorescence lifetimes of the samples were measured to investigate the luminescence properties. We analyzed the bidirectional energy transfer processes between Eu3+ and Tb3+ in NaLa(WO4)(2) and gave out the explanations. By adjusting the doping concentrations of Tb3+ and Eu3+, we obtained a phosphor that emits white light. Under the excitation of 382 nm, the chromaticity coordinate of NaLa0.96(WO4)(2):1%Eu3+,3%Tb3+ are (0.31,0.33) and the correlated color temperature is 6472 K, indicating that it can be used as a candidate for white light emission.