Intermolecular Electronic Coupling of Organic Units for Efficient Persistent Room-Temperature Phosphorescence

Area of Science:

• Materials Science
• Organic Chemistry
• Photophysics

Background:

• Persistent room-temperature phosphorescence (pRTP) in organic molecules lacks a unified mechanism and design strategy.
• Existing pRTP materials are limited, hindering broader applications.

Purpose of the Study:

• To establish a new mechanism and design strategy for organic pRTP materials.
• To develop bright pRTP with extended lifetimes and high quantum efficiency under ambient conditions.

Main Methods:

• Proposed a novel pRTP mechanism based on coupled intermolecular units with diverse excited-state configurations.
• Implemented a design strategy incorporating heavy halogen atoms to enhance intersystem crossing rates.
• Synthesized and characterized organic molecules exhibiting pRTP.

Main Results:

• Achieved persistent room-temperature phosphorescence (pRTP) with a lifetime of 0.28 seconds.
• Obtained a high quantum efficiency of 5% for the pRTP emission under ambient conditions.
• Demonstrated the effectiveness of the proposed mechanism and design strategy.

Conclusions:

• The new mechanism offers a versatile approach applicable to a wide range of organic molecules.
• The heavy halogen strategy successfully enhances pRTP brightness and longevity.
• This work advances the understanding and design of organic pRTP materials.