Reversible and Continuous Color-Tunable Persistent Luminescence of Metal-Free Organic Materials by "Self"-Interface...

Area of Science:

• Materials Science
• Organic Electronics
• Photophysics

Background:

• Metal-free organic materials offer ultralong exciton lifetimes for persistent luminescence.
• Achieving color-tunable persistent luminescence from single-component organic materials remains a significant challenge.

Purpose of the Study:

• To develop a single-component organic material with reversible, color-tunable persistent luminescence.
• To investigate the mechanism of color modulation using "self"-interface energy transfer (IET).

Main Methods:

• Utilized an organic phosphor (CTXO) exhibiting persistent room-temperature phosphorescence.
• Applied external physical stimuli (thermal annealing and mechanical grinding) to induce color changes.
• Analyzed the role of self-IET between crystalline and amorphous phases in color modulation.

Main Results:

• Demonstrated reversible, continuous color tuning of persistent luminescence between green and deep-yellow.
• Observed changes in luminescence lifetime from 0.24 s (green) to 0.10 s (deep-yellow).
• Identified self-IET from crystalline to amorphous regions as the key mechanism for color modulation.

Conclusions:

• Successfully designed a single-component organic material with stimuli-responsive, color-tunable persistent luminescence.
• Established "self"-interface energy transfer as a viable strategy for controlling persistent luminescence color.
• Opened new avenues for developing advanced stimuli-responsive smart materials with tailored optical properties.