Inorganic Chemistry, Vol.57, No.13, 7665-7675, 2018
Enhanced Photostability Luminescent Properties of Er3+-Doped Near White-Emitting DyxEr(1-x)-POM Derivatives
A series of Dy(x)Er((1-x))polyoxometalates (POMs) were successfully synthesized and characterized well by various physicochemical analysis. The structurally isolated compounds exhibit three characteristic emissions at 480 nm (blue, F-4(9/2) -> H-6(15/2) transition), 573 nm (yellow, F-4(9/2) -> H-6(13/2) transition), and 663 nm (red, F-4(9/2) -> H-6(11/2) transition) whose luminescent color coordinates appear in the near-white area in the CIE 1931 chromaticity diagram. Time resolved emission spectroscopy was used in DyxEr(1-x)-POM to further authenticate energy transfer from the photoexcitation 0 M ligand to the metal charge-transfer state of phosphotungstate components to active Dy3+/Er3+ ions and energy transfer between Dy3+ ion and Er3+ ion via intramolecular energy transitions. The relative emission intensity of similar to 32%, similar to 53%, and similar to 85% for DyPOM, Dy0.9Er0.1-POM, and Dy0.8Er0.2-POM respectively, were obtained under 300 min of UV irradiation, which indicates better photostability of Dy0.8Er0.2-POM. Furthermore, DyxEr(1-x)-POM samples can emit macroscopic white light under blue irradiation.