Synthesis and luminescent properties of Ba_(3)Y_(3.88)Gd_(0.12)O_(9):Eu^(3+) phosphors with enhanced red emission

In this work,the Gd^(3+)/Eu^(3+) activated Ba_(3)Y_(4)O_(9)(BYO)phosphors were successfully synthesized via coprecipitation method at 1400℃.The precursor composition,crystal structure stability,microscopic morphology,photoluminescence(PL)/photoluminescence excitation(PLE)spectra and fluorescence attenuation analysis of the phosphors are discussed in detail.The chemical composition of the precursor was determined by Fourier transform infrared spectroscopy(FT-IR)and thermogravimetry(TG)analysis;According to field emission-scanning electron microscopy(FE-SEM)analysis,it is found that the particle size of phosphor is uniform and the agglomeration is few.According to PL/PLE spectra analysis,Ba_(3)Y_(3.28)Eu_(0.6)Gd_(0.12)O_(9) phosphors has the strongest excitation band at 260 nm and the strongest emission band at 614 nm,and the fluorescence intensity of Ba_(3)Y_(3.28)Eu_(0.6)Gd_(0.12)O_(9) is higher than that of Ba_(3)Y^(3.4)Eu^(0.6)O_(9).The quenching concentration of Eu^(3+)in Ba_(3)Y_(3.88–4x)Eu_(4x)Gd_(0.12)O_(9) phosphors is x=0.15 and the mechanism of quenching concentration of Eu^(3+)is electric dipole-quadrupole type interactions.The lifetime value of Ba_(3)Y_(3.88–4x)Eu_(4x)Gd_(0.12)O_(9)(x=0.15)phosphors is 0.686 ms and decreases with the increase of Eu^(3+)content.In addition,the CIE chromaticity diagram of Ba_(3)Y_(3.28)Eu_(0.6)Gd_(0.12)O_(9) phosphors is(0.66,0.34).Finally,the lamp beads assembled with Ba_(3)Y_(3.28)Eu_(0.6)Gd_(0.12)O_(9) phosphors have an ideal luminous effect.Therefore,the Ba_(3)Y_(3.88–4x)Eu_(4x)Gd_(0.12)O_(9) phosphors designed in this work may hopefully meet the requirements of various lighting and optical display applications.