Photoluminescence and energy transfer investigations in Gd3+-Dy3+co-doped borate glasses

Abstract

We study energy transfer, Photo and X-ray luminescence in lithium barium borate glasses doped with Gd and Dy. We find that the Dy3+ luminescence at 575-nm emission wavelength increases while the Gd3+ emission at λem = 312 nm decreases, attributed to the energy transfer (ET) from the 6P7/2 state of Gd3+ ions to the 4F9/2 state of Dy3+ ions. From the 6P7/2 state decay lifetime (λexc = 275 nm and λem = 312 nm) of Gd3+ and that of the 4F9/2 state (λexc = 382 nm and λem = 575 nm) of the Dy3+, we compute the key parameters such as ET efficiencies, transfer probabilities and average donor-acceptor distance. Photometric parameters of the developed samples at λexc = 275 nm are calculated. Suggested by the Commission International deI’Eclairage coordinates, we infer that at 275-nm excitation, our optimized sample, LGBaB1.5Dy, produces white light. Measured from X-ray luminescence, the integral scintillation efficiency of LGBaB1.5Dy is 11%.