Infrequent blue and green emission transitions from Eu³⁺ in heavy metal tellurite glasses with low phonon energy

Eu³⁺ doped alkali-barium-bismuth-tellurite (Eu³⁺:LKBBT) glasses were prepared by conventional melt quenching. Twelve emission bands including infrequent blue and green bands are observed and they almost cover whole visible spectral region under violet light radiation. The blue and green emissions of Eu³⁺ rarely appeared in oxide glasses before, but they have been clearly recorded in Eu³⁺:LKBBT glasses even in the case of high concentration doping of Eu³⁺. The analysis based on spontaneous-radiative rate, energy gap and Raman scattering reveals that the obtaining of the abundant multichannel emissions of Eu³⁺ is due to the higher refractive index and the lower phonon energy in LKBBT glass system.