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

Abstract

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.