Tunable luminescence and temperature sensing behavior of Tb3+/Eu3+ co-doped borate glasses

The luminescent borate glasses co-doped Tb3+/Eu3+ were successfully synthesized by conventional melting quenching technique. Under 378 nm UV-light excitation, the 542 nm emission intensity of Tb3+ weakened gradually and a shorter decay time was found with increasing the content of Eu3+ concentration, confirming the occurrence of Tb3+ to Eu3+ energy transfer. The luminescent color tunable from pure green to yellow and finally to orange was observed in the Tb3+/Eu3+ co-doped borate glasses. The fluorescence intensity ratio between the 542 nm of Tb3+: D-5(4) -> F-7(5) transition and 702 nm of Eu3+: D-5(0) -> F-7(4) transition in the luminescent glass was found to be highly temperature-dependent with a good sensitivity of 0.357 % K-1. Such Tb3+/Eu3+ co-doped borate glasses may present potential application in solid-state lighting and optical temperature sensors.