Achieving high thermal stability of different rare-earth ions in a single matrix host via the manipulation of the local structure by a solid solution

Abstract

Thermal quenching seriously restricts the practical application of phosphors, particularly under high temperature and long-term working conditions. Here, we demonstrate that the as-obtained series of solid solutions of Ca_2−xY_xAl₂Si_1−xAl_xO₇:Tb³⁺ (x = 0–1, Ca₂Al₂SiO₇ → CaYAl₃O₇) phosphors exhibit an adjustable optical performance, where CaYAl₃O₇:Tb³⁺ exhibits a greatly improved thermal stability with a shortened bond distance of the related polyhedron compared with Ca₂Al₂SiO₇:Tb³⁺. The shrunken bond distance strengthens the pressure of the local structure and suppresses the non-radiative transition effectively, contributing to the prevention of the thermal degradation. The formed phosphor with excellent structural stability could be effectively incorporated with various lanthanide ions (Eu³⁺, Tb³⁺, Sm³⁺, Dy³⁺, and Pr³⁺) to address a pleochroism output.