Charge transfer characteristics and luminescence properties of Eu3+ activated Ba2YMoO6 and BaY2(MoO4)4 phosphors

Abstract Octahedrally and tetrahedrally connected Mo-O complexes in two different crystal phases were comparatively investigated. The material Ba2YMoO6:Eu3+ exhibits the cubic perovskite structure for which the Mo-O groups are coordinated octahedrally, while BaY2(MoO4)4:Eu3+ has a monoclinic crystal phase for which the Mo-O complexes are connected tetrahedrally. The photoluminescence (PL) excitation spectra show that, the intensity, position and shape of the charge transfer (CT) transitions in the two different materials depended strongly on the surrounding environment. The PL emission properties of Ba2YMoO6:Eu3+ and BaY2(MoO4)4:Eu3+ phosphors as a function of various doping content of Eu3+ ions excited at different wavelengths were explored in detail. The critical concentration of Eu3+ and the critical distance between Eu3+ ions, as well as the concentration quenching effects were discussed. The absolute quantum yield for the monoclinic phase BaY2(MoO4)4:Eu3+ phosphor was about an order of magnitude higher than that of the cubic phase Ba2YMoO6:Eu3+ phosphor.