Investigation on the determinant of upconversion luminescence efficiency and temperature measurement sensitivity based on AWO4 (Ba, Sr, Ca, and Mg): Er3+/Yb3+ microcrystals

In this work, a comparative study of the upconversion (UC) luminescence properties of Er3+-Yb3+-co-doped AWO(4) (A D Ba, Sr, and Ca) scheelite phosphors and Er3+-Yb3+-co-doped MgWO4 wolframite phosphors is reported. Under 980 nm excitation, all the samples emit green and red emissions. The Er3+-Yb3+-doped MgWO4 phosphor has a higherUCemission intensity. Furthermore, the optical temperature sensing properties in Er3+-Yb3+-co-doped AWO(4) (A D Ba, Sr, Ca, and Mg) phosphor samples are investigated. The relative sensitivity (S-r) based on thermally coupled levels (TCLs) increases gradually with an increase in matrix phonon energy. The absolute sensitivity (S-a) values of the samples are accurately predicted by the chemical bonding parameter (f(c)). The results of the correlation between the UC luminescence properties and the microscopic crystal structure, and the relationship of the temperature sensitivity and the host parameters, provide us with a guiding insight for the selection of a host material with ideal temperature measurement capability. (c) 2022 Optica Publishing Group