Boosting purely organic room-temperature phosphorescence performance through a host-guest strategy

Area of Science:

• Materials Science
• Photochemistry
• Solid-State Chemistry

Background:

• Host-guest doping systems show promise for bright and persistent room-temperature phosphorescence (RTP).
• Understanding structure-property relationships in these bicomponent systems remains challenging.

Purpose of the Study:

• To design and synthesize novel heterocyclic isomers for solid-state RTP.
• To develop host-guest cocrystalline systems for enhanced RTP performance.
• To elucidate the structure-property relationships governing RTP in these systems.

Main Methods:

• Synthesis of heterocyclic isomers and phosphorus-containing host materials.
• Formation of host-guest cocrystalline systems.
• Photophysical characterization (quantum efficiency, lifetime).
• Molecular dynamics (MD) simulations.

Main Results:

• Achieved highly efficient RTP with phosphorescence quantum efficiency (ϕP) of ~26% and lifetime (τP) of ~32 ms.
• Demonstrated that the host matrix restricts guest molecular configuration.
• Showed host matrix dilutes guest to prevent concentration quenching.
• Confirmed host matrix provides an external heavy atom effect to boost triplet exciton population.

Conclusions:

• Host-guest cocrystalline systems can significantly enhance RTP performance.
• The host matrix plays multiple roles in optimizing RTP, including structural control, dilution, and heavy atom effects.
• This work provides insights into designing efficient RTP materials through host-guest engineering.