Phonon assisted effective non-resonant energy transfer based 1 μm luminescence from Nd3+–Yb3+ codoped zinc–boro–bismuthate glasses

Phonon assisted non-resonant energy transfer from Nd3+→Yb3+ is reported in a new series of heavy metal oxide based zinc–boro–bismuthate glasses. An intense infrared emission at around 1 μm from Yb3+ has been realized upon Nd3+ excitation, with a transfer efficiency reaching up to 87% for fairly low acceptor concentration of 1 mol% Yb2O3. Such high energy transfer efficiency despite poor spectral overlap of donor’s emission with acceptorʹs absorption has been attributed to the excellent matching of host phonon energy with the energy difference among Nd3+ and Yb3+ excitation levels. From the host assisted spectral overlap function, the microscopic energy transfer parameter (CDA) for Nd3+→Yb3+ energy transfer in these glasses have been estimated and is found to be ∼3.6×10−39 cm6 s−1, which is in good agreement with the CDA value obtained from decay analysis of donor luminescence. The measured fluorescence decay curve showed excellent correlation with the theoretical fit simulated using hopping model suggesting the hopping migration assisted energy transfer. A comparison of the obtained results with other reported host systems has been presented using a performance parameter (ΦET) defining the ability of Nd3+→Yb3+ energy transfer per unit loss occurred due to Nd3+–Nd3+ self-quenching.