Luminescence properties in relation to controllable morphologies of Ba[GeBO(OH)](OH)(HO):Eu and its thermal conversion product BaGeBO:Eu.

Three types of morphologies of Eu-doped BaGeBO(OH)(HO) phosphors were obtained hydrothermal reactions by different kinds of raw materials. In addition, BaGeBO:Eu phosphors were obtained by calcining the precursor BaGeBO(OH)(HO):Eu. 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 BaGeBO(OH)(HO) were investigated in detail. The lifetime and absolute quantum yield (QY) of different morphologies of BaGeBO(OH)(HO):Eu were also measured. The PL properties of the BaGeBO:Eu phosphor prepared by the precursor calcination method compared with those prepared by the high-temperature solid-state method are discussed.