Optical properties of Eu3+-doped zinc borate glasses

Photoluminescence, absorption and optical excitation spectra of undoped and Eu3+-doped binary zinc borate glasses of varied composition prepared by the melt quenching technique in air atmosphere were investigated. From photoluminescence measurements it was found that growing Eu3+ concentration leads to gradual disappearance of the broadband glass emission in the near-UV spectral range, while the red Eu3+ emission at 613 nm shows a considerable increase. This result together with excitation spectra suggests that the Eu3+ ions are excited via energy transfer from the initially excited glassy host. The glass composition strongly affects the position of the excitation maximum in the UV energy range.