Luminescence properties in relation to controllable morphologies of Ba3[Ge2B7O16(OH)2](OH)(H2O):Eu3+ and its thermal conversion product Ba3Ge2B6O16:Eu3+

Abstract

Three types of morphologies of Eu³⁺-doped Ba₃[Ge₂B₇O₁₆(OH)₂](OH)(H₂O) phosphors were obtained via hydrothermal reactions by different kinds of raw materials. In addition, Ba₃Ge₂B₆O₁₆:Eu³⁺ phosphors were obtained by calcining the precursor Ba₃[Ge₂B₇O₁₆(OH)₂](OH)(H₂O):Eu³⁺. The structure and morphology of the obtained samples were characterized by XRD, EDS, FT-IR, TG-DTA, SEM and HRTEM. Herein, the effects of the synthesis parameters, including the reaction temperature, boron sources and the rare earth doping dosage, on the photoluminescence (PL) properties of Ba₃[Ge₂B₇O₁₆(OH)₂](OH)(H₂O) were investigated in detail. The lifetime and absolute quantum yield (QY) of different morphologies of Ba₃[Ge₂B₇O₁₆(OH)₂](OH)(H₂O):Eu³⁺ were also measured. The PL properties of the Ba₃Ge₂B₆O₁₆:Eu³⁺ phosphor prepared by the precursor calcination method compared with those prepared by the high-temperature solid-state method are discussed.