Sulfone-Isoquinoline Dopants Activated Phosphorescence Beyond Room Temperature

Area of Science:

• Materials Science
• Organic Chemistry
• Photophysics

Background:

• Organic room-temperature phosphorescence (RTP) is vital for advanced applications.
• Reliability issues in single-component RTP systems stem from impurity dependence.

Purpose of the Study:

• To investigate the role of impurities in sulfone-based RTP materials.
• To develop a reproducible method for creating stable organic RTP systems.

Main Methods:

• Systematic investigation of sulfone-based materials.
• Doping experiments with a sulfone-isoquinoline derivative (SO2PzQ7).
• Thermal stability and reversibility testing.
• Theoretical calculations (DFT) to elucidate the mechanism.

Main Results:

• Pure sulfone-based materials showed no RTP, confirming impurity dependence.
• Doping with 0.01 wt% SO2PzQ7 activated intense yellow RTP with a 273 ms lifetime.
• The doped system demonstrated high thermal stability (up to 413 K) and reversible on-off switching over six cycles.
• The strategy was successfully extended to other sulfone derivatives.

Conclusions:

• Trace impurities act as critical "trap sites" for enabling RTP in organic materials.
• A generalizable doping strategy using sulfone-isoquinoline derivatives creates reproducible, thermally stable, and reversible RTP systems.
• Host-guest energy transfer mechanism facilitates efficient intersystem crossing and triplet stabilization.