Pressure-induced photoluminescence enhancement of CeF₃:Tb³⁺ nanoparticles

Rare earth fluorides have been widely used in recent years in the field of solid-state lighting. However, the relationship between the structure and luminescence properties is still unclear. Herein, the photoluminescence and structural transition of CeF₃:Tb³⁺ nanoparticles under high pressure were investigated through in situ photoluminescence and X-ray diffraction measurements. Intriguingly, the photoluminescence of CeF₃:Tb³⁺ nanoparticles displays an enhancement from 18.3 to 33.4 GPa, accompanied by the phase transition from the starting hexagonal phase to the orthorhombic phase. It was found that the distance of luminescent centers increased sharply during the high-pressure phase transition, which weakened the quenching effect and improved transmission efficiency. Our work provides more insight into the optical characteristics and structures of rare earth trifluorides.