Ultrahigh-Temperature Long-Persistent Luminescence from B₂O₃-Confined Polycyclic Aromatic Compounds

Area of Science:

• Materials Science
• Photophysics
• Organic Chemistry

Background:

• Organic molecules and polymers are explored for afterglow materials due to cost and design flexibility.
• Challenges exist in achieving long-persistent luminescence at high temperatures due to rapid triplet excited state deactivation.

Purpose of the Study:

• To develop organic afterglow materials capable of sustained luminescence at elevated temperatures.
• To investigate the mechanism behind high-temperature long-persistent luminescence in confined organic molecules.

Main Methods:

• Dispersing polycyclic aromatic compounds (PACs) in boric acid solution.
• Drying, melting, and dehydrating to form a B2O3 crystalloid network.
• Characterizing the luminescence properties of PACs confined within the B2O3 matrix at high temperatures.

Main Results:

• PACs confined in B2O3 crystalloids demonstrated long-persistent luminescence up to 400°C.
• The rigid B2O3 network restricted molecular motion, preventing nonradiative decay of triplet excitons.
• Afterglow colors were tunable from UV to NIR, responding to temperature and time via phosphorescence and thermally activated delayed fluorescence.

Conclusions:

• Confining PACs within a B2O3 crystalloid is an effective strategy for achieving ultra-high-temperature long-persistent luminescence.
• The developed materials show promise for applications in 3D temperature probing, anticounterfeiting, and data encryption in extreme conditions.