Highly Efficient Persistent Room-Temperature Phosphorescence from Heavy Atom-Free Molecules Triggered by Hidden Long...

Area of Science:

• Materials Science
• Photophysics
• Organic Chemistry

Background:

• Persistent room-temperature phosphorescence (pRTP) is crucial for advanced security and bioimaging.
• Current limitations in RTP yield (>50%) and lifetime (>1 s) stem from an unclear chromophore-parameter relationship.
• Heavy atom incorporation is often used to enhance phosphorescence, but this study explores alternatives.

Purpose of the Study:

• To develop highly efficient, heavy atom-free chromophores for pRTP under ambient conditions.
• To elucidate the relationship between molecular structure and phosphorescence parameters.
• To achieve pRTP with high quantum yield and long lifetime.

Main Methods:

• Design and synthesis of novel heavy atom-free aromatic chromophores with long-conjugated amino groups.
• Characterization of photophysical properties, including RTP yield and lifetime.
• Investigation of the phosphorescence rate acceleration mechanism independent of non-radiative decay.

Main Results:

• Achieved highly efficient pRTP from heavy atom-free chromophores at room temperature and ambient conditions.
• One designed chromophore exhibited a 50% RTP yield and a 1-second lifetime.
• Demonstrated afterglow brightness over 10^4 times stronger than conventional long-persistent luminescence emitters.
• Showcased high-resolution gated emission capabilities using low-cost photodetectors.

Conclusions:

• The developed heavy atom-free chromophores significantly enhance phosphorescence rates.
• The findings overcome previous limitations in RTP yield and lifetime.
• These materials enable advanced applications in high-resolution imaging and security.