Solid state synthesis, tunable luminescence and thermal stability of NaCaBO3:Eu2+/Mn2+ phosphors

NaCaBO3:Eu2+ and NaCaBO3:Eu2+/Mn2+ phosphors have been synthesized successfully through a solid state reaction. The phase and luminescent properties of the obtained phosphors also have been studied carefully. The X-ray powder diffraction (XRD) patterns suggest that all of obtained phosphors have the pure orthorhombic structure of NaCaBO3. Under the excitation of 330 nm, NaCaBO3:Eu2+ phosphors show a single emission band in blue-green region. Under the excitation of 330 nm, NaCaBO3:Eu2+/Mn2+ phosphors exhibit two emission bands peaking at about 477 nm and 602 nm, which originate from the Eu2+ and Mn2+ ions, respectively. The tunable luminescence is obtained for NaCaBO3:Eu2+/Mn2+ phosphors by adjusting the concentrations of Eu2+ and Mn2+ ions. The tunable luminescence is induced by the energy transfer from Eu2+ to Mn2+ in NaCaBO3 host, which is confirmed by the spectral overlap between the emission band of NaCaBO3:Eu2+ and the excitation band of NaCaBO3:Mn2+ and the decreasing lifetimes of Eu2+ emission with the increasing Mn2+ concentrations. (C) 2016 Elsevier Ltd and Techna Group S.r.l. All rights reserved.