Polymer-Based p‑Type Exciplex Systems for Air-Stable and Processable Organic Persistent Luminescence

Area of Science:

• Materials Science
• Organic Electronics
• Photophysics

Background:

• Existing exciplex systems for persistent luminescence (PersL) are typically n-type or small-molecule based.
• These systems suffer from rapid oxygen quenching and poor processability, limiting their practical applications.
• There is a need for robust, process-friendly materials exhibiting long-lasting organic PersL.

Purpose of the Study:

• To report the first p-type polymer-based multicomponent exciplex system with persistent luminescence (PersL).
• To address the limitations of oxygen sensitivity and poor processability in existing PersL materials.
• To establish a versatile platform for organic PersL applications.

Main Methods:

• Fabrication of a p-type polymer exciplex using poly-(N-vinylcarbazole) as the host, a pyrylium derivative as the acceptor, and a diamine derivative as the trap material.
• Characterization of persistent luminescence properties, including afterglow duration.
• Investigation of charge carrier dynamics and environmental effects on PersL.
• Demonstration of anticounterfeiting applications using a multilayer QR-code.

Main Results:

• Achieved persistent luminescence (PersL) with an afterglow exceeding 3 hours.
• The developed system is oxygen-tolerant and exhibits excellent thermal moldability.
• A simple one-pot 'boil-up' protocol followed by annealing enables easy material preparation.

Conclusions:

• The study presents a novel, robust, and process-friendly p-type polymer-based exciplex for organic PersL.
• This material overcomes critical drawbacks of previous systems, paving the way for wider applications.
• Potential applications include anticounterfeiting, data encryption, and wearable photonic devices.