Efficient luminescence lifetime thermometry with enhanced Mn4+-activated BaLaCa1-xMgxSbO6 red phosphors

Mn4+-activated phosphors are of great interest in luminescence lifetime thermometry due to the luxuriant luminescence properties influenced by the locally surrounding crystal field. It is highly desirable to develop effective Mn4+-based luminescence lifetime thermometry through modulating the structural parameters. In this work, by introducing the smaller Mg2+ ions to replace Ca2+ site in the BaLaCaSbO6 matrix, a 4.2-fold enhance in the luminescence intensity, red-shifted from 690 nm to 698 nm, as well as luminescence lifetime increase from 0.212 to 0.951 ms is achieved. These modulations are mainly attributed to the strengthen pressure on the local structure, superior lattice rigidity and suppresses non-radiative transition after the substitution of smaller Mg2+. Interestingly, owing to the obvious thermal quenching behavior of Mn4+ ions in the matrix, effective lifetime-based luminescence thermometry can be realized. Mg2+ dopant results in the improvement of the absolute sensitivity from 1.22 mu sK(-1) (BaLaCaSbO6:Mn4+@408 K) to 4.88 mu sK(-1) (BaLaCa0.1Mg0.9SbO6:Mn4+@401 K).