Effect of RO (R=Ca, Sr, Ba, Zn or Pb) component on spectroscopic properties of Eu3+ in RO-B2O3 glasses

Eu3+-doped binary borate glasses with different metal oxide components RO (R=Ca, Sr, Ba, Zn or Pb) were prepared by melt-quenching technique. The fluorescent spectral properties of Eu3+ in these glasses were experimentally studied. The analysis on the phonon sidebands (PSBs) indicated that RO component did not cause obvious change of the electron-phonon coupling constant (EPC). By inspecting the optical absorption edges it was found that RO could greatly affect the band gap energy, and the glass with PbO component revealed the smallest band gap energy, the glasses with ZnO, BaO and SrO showed similar band gap energy. The optical transition intensity parameters of Eu3+ in all studied glasses were calculated, it was found that for each sample its value of Ω2 was larger than that of Ω4 and Ω6, and the sample with PbO component exhibited the smallest Ω2, but the Ωλ values for ZBE, CBE, BBE and SBE were very similar. These results might be helpful for the design of borate glasses.