Hongling Yu

Improvement of the energy transfer from Ca3SnSi2O9 host to rare-earth ions with the assistance of oxygen vacancies

The blue emission of Ca3SnSi2O9 was identified to arise from the recombination of electrons and holes via intrinsic oxygen vacancy defects using photoluminescence spectra measurements, density functional theory calculations, and thermoluminescence analysis. A significant enhancement in the photoluminescence intensity of the blue emission was observed in samples of Ca3SnSi2O9 co-doped with fluorine, which was attributed to the increased number of oxygen vacancy defects produced in Ca3SnSi2O9. Most importantly, the improvement of the photoluminescence intensity of Dy3+ demonstrated that energy transfer from the Ca3SnSi2O9 host to the activators became more effective when fluorine was co-doped. It indicates that fluorine could be introduced into the Ca3SnSi2O9 host by this approach, which produced more oxygen vacancies and contributed to the improved photoluminescence performance of the activators.