Full-Color Tunable Time-Dependent Room-Temperature Phosphorescence from Self-Protective Carbonized Polymer Dots

Area of Science:

• Materials Science
• Organic Electronics
• Photophysics

Background:

• Achieving full-color time-dependent tunable phosphorescence (TDTP) in organic materials is difficult due to issues with nonradiative transitions and triplet state modulation.
• Pure organic materials often struggle to achieve stable and tunable phosphorescence across the visible spectrum.

Purpose of the Study:

• To realize full-color TDTP in pure organic materials using carbonized polymer dots (CPDs).
• To investigate the mechanisms behind dual emission centers and their role in dynamic color tuning.
• To explore potential applications of these novel phosphorescent materials.

Main Methods:

• Synthesis of self-protective carbonized polymer dots (CPDs) via a self-doping strategy.
• Utilizing dual emission centers: N-related triplet state (blue) and surface oxide triplet state (green-red).
• Employing experimental characterization and theoretical calculations to understand aggregation-induced color shifts.

Main Results:

• Successfully achieved full-color TDTP in matrix-free CPDs under ambient conditions.
• Demonstrated dynamic color emission from blue to red (453-609 nm) upon aggregation.
• Confirmed that increased C═O content and aggregation degree lead to red-shifted afterglow due to energy level reduction.

Conclusions:

• CPDs with dual emission centers enable dynamic TDTP across the visible spectrum.
• The developed CPDs exhibit excellent photostability and potential for applications in information encryption and time-delayed LEDs.