High-Temperature Afterglow Color Tuning via Förster Resonance Energy Transfer

Area of Science:

• Materials Science
• Chemistry
• Optics

Background:

• Persistent luminescence materials (LPMs) exhibit long afterglow, making them suitable for sensing, anti-counterfeiting, and bioimaging.
• Thermal quenching significantly limits LPM performance at elevated temperatures.
• Conventional inorganic matrices require high-temperature processing, complicating organic dopant integration and color tuning.

Purpose of the Study:

• To develop high-temperature persistent luminescence materials with tunable colors.
• To overcome the limitations of thermal quenching in LPMs.
• To explore Förster resonance energy transfer (FRET) in organic-inorganic hybrid systems for luminescence applications.

Main Methods:

• Fabrication of a low-temperature processed boric acid matrix doped with triphenylboronic acid (TPBA).
• Formation of a crystalline metaborate network via mild heating (120°C) to confine TPBA.
• Incorporation of Rhodamine 6G as an acceptor to facilitate triplet-to-singlet FRET.

Main Results:

• The crystalline metaborate network effectively confines TPBA, yielding a phosphorescence lifetime of up to 2.56 s at 460 K.
• The material demonstrates suppressed vibrational loss and stable triplet exciton dynamics at high temperatures.
• Efficient FRET from blue-green phosphorescence to red fluorescence was achieved, with color tunability observed by adjusting acceptor concentration or temperature.

Conclusions:

• A novel strategy combining a low-temperature boric acid matrix with FRET enables the creation of thermally stable, multicolor LPMs.
• The mild synthesis conditions prevent dopant decomposition and expand the scope of organic-inorganic hybrid FRET systems.
• This approach offers a simple and effective route to advanced LPMs with enhanced thermal stability and adjustable emission colors.