Manipulation of Temperature-Dependent Luminescence Behaviors of Mn⁴⁺-Activated Fluoride Phosphors

Abstract

In this paper, the giant tunability of thermal behaviors, i.e., from thermal deterioration to substantial growth, is firmly demonstrated for the vibronic luminescence of Mn 4+ ions in fluoride phosphors. Such peculiar behavior is uncovered to be associated with the thermal excitation of a low-frequency phonon bath, and a theoretical model involving the excitation-wavelength-dependent populations of vibronic levels and the temperaturedependent nonradiative recombination processes is successfully constructed. Two main governing parameters, namely, the thermal activation energy E a and the involved average phonon energy ΔE, are thus determined for the distinct thermal behaviors of Mn 4+ -ion luminescence. This demonstration may pave the way for manipulating the thermal behaviors of vibronic luminescence in solids to some extent.

Thermally enhanced NIR up-conversion fluorescence multimode thermometry based on Y2Mo3O12:Nd3+,Yb3+

“…12,13 Although a lot of works have been done for combating the thermal quenching, including surface engineering (passivation or ligand coordination), high-power excitation, phononassisted energy transfer (PAET), etc., only limited success has been achieved due to different difficulties faced by each method and non-universality. [14][15][16] In recent years, negative thermal expansion (NTE) based luminescent materials showed good prospects in anti-thermal quenching due to their fascinating luminescence promoting capability from structures. Specifically, the microscopic volume of NTE materials will decrease with the increase of temperature and the gradually compact lattice reduces the phonon energy corresponding to the various vibration modes, which can reduce the energy loss caused by NR.…”