Synthesis, structure, and luminescence properties of a new Eu3+-doped Ca3Tb7(BO4)(SiO4)5O oxyapatite red phosphor

A series of Eu3+-doped Ca3Tb7(BO4)(SiO4)(5)O red phosphors with apatite structure have been synthesized via high-temperature solid-state method. It could be concluded from XRD results that pure Ca3Tb7(BO4)(SiO4)(5)O: Eu3+ phase was obtained. The structure refinement results confirmed that the space group of Ca3Tb7(BO4)(SiO4)(5)O: Eu3+ was P-63/m and Eu3+ tended to replace some of Tb3+ in [Ca0.573Tb0.427O9]. Morphology and structural analysis were carried out by scanning electron microscopy (SEM), high transmission electron microscope (HTEM), selected area electron diffraction (SAED), Fourier transform infrared (FTIR), and Raman spectroscopy. The strongest emission peak of the emission spectrum under 259 nm excitation was located at 614 nm, which corresponded to the characteristic emission peak of Eu3+. When the doping concentration of Eu3+ was higher than 0.8 mol%, the concentration quenching effect occurred. Tb3+ ions served as the sensitizer transferred the absorbed energy to Eu3+ ions effectively with the maximum transfer efficiency of 89.36%. The temperature-dependent photoluminescence emission spectra exhibited it possessed good thermal stability. The fabricated LED device combining Ca3Tb7(BO4)(SiO4)(5)O: 0.8 molEu(3+) with a 265 nm UV chip emitted brilliant red light. Ca3Tb7(BO4)(SiO4)(5)O: Eu3+ provided a new choice for red phosphors used in w-LEDs.