Sensitized red luminescence from Bi3+ co-doped Eu3+: ZnO-B2O3 glasses

Photoluminescence properties of Bi3+ co-doped Eu3+ containing zinc borate glasses have been investigated and the results are reported here. Bright red emission due to a dominant electric dipole transition 5D0→7F2 of the Eu3+ ions has been observed from these glasses. The nature of Stark components from the measured fluorescence transitions of Eu3+ ions reveal that the rare earth ions could take the lattice sites of Cs or lower point symmetry in the zinc borate glass hosts. The significant enhancement of Eu3+ emission intensity by 346 nm excitation (1S0→3P1 of Bi3+ ions) elucidates the sensitization effect of co-dopant. The energy transfer mechanism between sensitizer (Bi3+) and activator (Eu3+) ions has been explained.