Thermally activated processes in an organic long-persistent luminescence system

Area of Science:

• Materials Science
• Photophysics
• Organic Electronics

Background:

• Long-persistent luminescence (LPL) materials store and emit light, with inorganic types being crystalline and often rare-metal-dependent.
• Organic LPL (OLPL) materials offer flexibility and avoid rare metals, but their charge separation and accumulation mechanisms are not fully understood.
• The emission process in OLPL involves photoinduced charge separation, accumulation, and recombination-induced emission.

Purpose of the Study:

• To investigate the charge carrier dynamics in a binary OLPL system composed of electron donors and acceptors.
• To elucidate the enigmatic charge separation and accumulation processes in OLPL systems.
• To confirm the presence and nature of thermal activation phenomena in OLPL.

Main Methods:

• Utilized a binary OLPL system comprising electron donors and acceptors.
• Investigated charge carrier dynamics through experimental analysis.
• Confirmed the presence of specific photophysical processes.

Main Results:

• Confirmed the presence of thermal activation processes within the OLPL system.
• Identified and confirmed thermally activated delayed fluorescence (TADF).
• Observed and confirmed thermoluminescence (TL) in the studied OLPL system.

Conclusions:

• The study provides crucial insights into the charge carrier dynamics of organic long-persistent luminescence (OLPL) materials.
• Confirmed that thermal activation, TADF, and thermoluminescence are integral to the functioning of this binary OLPL system.
• This research advances the understanding of OLPL mechanisms, paving the way for novel material design.