Efficient Organic D-π-A Scintillators for Temperature-Adaptive X-Ray Imaging.

Area of Science:

• Materials Science
• Organic Electronics
• Photophysics

Background:

• Organic scintillators are crucial for X-ray imaging but face challenges in efficient exciton decay.
• Developing materials with rapid radiative decay for both singlet and triplet excitons is a key hurdle.

Purpose of the Study:

• To introduce a novel design strategy for efficient organic scintillators using fluorine-modified D-π-A molecules.
• To investigate the photophysical properties and X-ray detection capabilities of these new materials.

Main Methods:

• Synthesized D-π-A molecules (1FAT and 2FAT) with fluorine atoms incorporated into the π-bridge.
• Evaluated photoluminescence, thermally activated delayed fluorescence (TADF), aggregation-induced delayed fluorescence (AIDF), and room temperature phosphorescence (RTP).
• Assessed radioluminescence performance of 1FAT doped in PMMA film under X-ray excitation.

Main Results:

• 1FAT and 2FAT emitters demonstrated efficient TADF, AIDF, and RTP properties.
• 1FAT@PMMA film showed stable, intense emission from 77 to 363 K, indicating excellent temperature adaptability.
• 1FAT@PMMA film achieved a low X-ray detection limit (62.27 nGy s⁻¹) and high spatial resolution (>20 lp mm⁻¹).

Conclusions:

• A novel design strategy using fluorine modification of D-π-A molecules enables efficient organic scintillators.
• The developed materials exhibit superior temperature adaptability and radioluminescence performance.
• This approach holds significant potential for flexible, stretchable X-ray detectors and advanced imaging.