The downshifting and upconversion photoluminescence from NaBaSc2(PO4)3 for multicolor anti-counterfeiting

Abstract

A novel langbeinite-type phosphate NaBaSc2(PO4)3 (NBSP) was synthesized by traditional solid-state reaction. The structure was refined on the basis of X-ray diffraction data. The Rietveld refinement result revealed that the structure of NBSP belongs to cubic system with space group P213 and cell parameters a = 10.0392 Å, b = 10.0392 Å, c = 10.0392 Å, α = β = γ = 90°, V = 1011.80 Å3, and Z = 4. The incorporations of Ce3+/Eu2+-Tb3+ into NBSP led to efficient downshifting emissions with adjustable color from blue to yellow. The luminescent properties, energy transfer and application in white light-emitting diode (WLED) were studied comprehensively. Moreover, blue, yellow and red upconversion emissions were also realized in NBSP by codoping Yb3+-Tm3+/Er3+/Ho3+, respectively. Finally, highly distinguishable luminescent images were obtained under the excitation of 254 nm, 365 nm or 980 nm, based on multiple NBSP phosphors with designed photoluminescence for the application in multicolor anti-counterfeiting. These results point out a practical approach for convenient and reliable anti-counterfeiting.