Photoluminescence of Tb3+-doped LiF-BaF2-Lu2O3-Al2O3-SiO2 glasses

LiF-BaF2-Lu2O3-Al2O3-SiO2 glasses doped with Tb3+ ions were obtained by melt-quenching technique, and their transmission and photoluminescence properties were investigated. The X-ray diffraction (XRD) and luminescence decay profiles of these prepared samples have been obtained to confirm their structure and luminescence dynamics. The prepared oxyfluoride glasses doped with Tb3+ ions exhibit high transmittance in the visible light region, and the UV absorption edge appears red-shifted as the Tb2O3 content increases in the LiF-BaF2-Lu2O3-Al2O3-SiO2 oxyfluoride glasses. Under UV excitation, the Tb3+ ions emissions corresponding to D-5(3) (D-5(4)) -> F-7(J) (J = 6-3) electron transitions can be detected. With the increase of Tb2O3 content, the green light emission intensities caused by the Tb3+ ions D-5(4) -> F-7(J) (J = 6-3) electron transitions are enhanced, while the blue light emission intensities induced by the Tb3+ ions D-5(3) -> F-7(J) (J = 6-3) electron transitions first increased to the maximum until the introduction of Tb2O3 was equal to 0.3 mol, and then decreased with the Tb2O3 content further increase. The mechanism involved in the resonance energy transfer (RET) process between Tb3+ - Tb3+ ions was explained with an energy level diagram. And the luminescence decay times of Tb3+ ions electron transition originated from D-5(4) energy level continue to decrease from 3.171 to 2.250 ms with increasing Tb2O3 content in the LiF-BaF2-Lu2O3-Al2O3-SiO2 glasses.