Luminescence properties and energy transfer of YGa1.5Al1.5(BO3)4:Tb3+,Eu3+ as a multi-colour emitting phosphor for WLEDs†
A series of YGa1.5Al1.5(BO3)4:Tb3+,Eu3+ inorganic luminescence materials were successfully synthesized through a high-temperature solid-state reaction. Powder X-ray diffraction was used to confirm the crystal structure and phase purity of the obtained samples. Then, scanning electron microscopy elemental mapping was taken to characterize the distribution of the doped ions. Detailed investigations on the photoluminescence emission and excitation spectra and fluorescence lifetime revealed that trivalent europium ions can be well sensitized by trivalent terbium ions under near-ultraviolet excitation. Additionally, the energy transfer from Tb3+ to Eu3+ can be controlled to realize multi-colour emissions covering the green to red visible region. Concentration quenching does not take place in Tb3+ or Eu3+ singularly-doped YGAB due to its structure isolation. Therefore, satisfactory luminescence properties related to the structure specificity make these phosphors suitable for WLEDs.