Wide-range lifetime-tunable and responsive ultralong organic phosphorescent multi-host/guest system

Area of Science:

• Materials Science
• Organic Chemistry
• Photophysics

Background:

• Ultralong organic phosphorescence (UOP) is crucial for advanced applications but lacks effective lifetime-tuning strategies.
• Controlling UOP emission lifetimes is essential for time-resolved information display and security features.

Purpose of the Study:

• To develop a rational strategy for dynamically tuning the emission lifetimes of UOP materials.
• To investigate the relationship between host matrix properties and UOP characteristics.
• To explore the potential of these UOP materials in time-resolved information displaying and anti-counterfeiting.

Main Methods:

• Synthesized multi-host/guest UOP systems by doping emitters into various solid host matrices.
• Systematically varied host matrix triplet energy levels to achieve lifetime tuning.
• Investigated photophysical properties, including emission spectra, lifetimes, and temperature-dependent behavior.
• Analyzed the role of host matrices in stabilizing triplet excitons.

Main Results:

• Achieved a wide range of UOP lifetimes (3.9 ms to 376.9 ms) with stable emission colors.
• Demonstrated excitation-dependent phosphorescence and temperature-controlled on/off switching of afterglow.
• Confirmed that host matrices provide rigid environments and suitable energy levels for exciton stabilization.

Conclusions:

• A guiding strategy for lifetime-tunable UOP materials with lifetime-order encoding was established.
• The developed UOP materials show promise for time-resolved displays, security protection, and anti-counterfeiting.
• This work opens new avenues for designing advanced optoelectronic materials with dynamic functionalities.