White light emission of Ce3+ sensitized Sm3+ doped lead alumino borate glasses

In present work, Ce3+ activated Sm3+ doped lead alumino borate glasses have been synthesized by melt quench method. Photoluminescence spectra were measured under different excitation wavelengths. The co-doped samples show enhanced Sm3+ ions emission at the cost of Ce3+ emission with the increasing Ce3+ ions concentration which shows that Ce3+ is acting as a sensitizer. This kind of luminescent behavior is discussed with respect to energy transfer process. The investigation based on excitation spectra and decay curves demonstrated that the energy transfer is nonradiative in nature taking place between Ce3+ and Sm3+ clusters. It is governed by dipole-dipole interactions as explained in terms of donor lifetime. The results showed that the white light has been achieved under excitation at 400 nm when concentration of Ce3+ is in the range of 0.5-1.0 mol%. An efficient energy transfer from Ce3+ to Sm3+ ions (up to around 42%) with decay times approaching 22 ns has been observed at 400 nm excitation. The UV-Vis absorption spectra shows an increase in intensity and a significant red-shift of the optical absorption edge with increasing rare earth ions concentration in lead alumino borate glass and the FTIR study depicts the conversion of trigonal BO3 units into more stable tetrahedral BO4 units.