[18a-M_B104-1~10] 12.4 Organic light-emitting devices, organic transistors, and flexible devices

10:00 AM - 10:15 AM JST(1:00 AM - 1:15 AM UTC)Presentation by Applicant for JSAP Young Scientists Presentation Award

[18a-M_B104-5] Unraveling Exciton Dynamics in a TADF Molecule Demonstrating Sub-Microsecond and Mono-Exponential Transient PL Decay in Solution

〇(D)Shoma Sasaki^1,2, Wen-Hao Zhang³, Youichi Tsuchiya², Debasish Barman², Chih-Hsin Chen³, Chihaya Adachi^1,2,4 (1.Grad. Sch. of Eng., Kyushu Univ., 2.OPERA Kyushu Univ., 3.Grad. Sch. of Sci., Tamkang Univ., 4.WPI-I2CNER, Kyushu Univ.)

Keywords:

Thermally activated delayed fluorescence,Transient photoluminescence,Exciton dynamics

In this study, we investigated the exciton dynamics of DMAc-sFL-PN, a molecule previously reported to exhibit thermally activated delayed fluorescence (TADF) through rapid equilibrium spin-conversion. Despite its classification, the molecule displays an exceptionally fast, mono-exponential transient photoluminescence (TrPL) decay with a lifetime of 460 ns in solution, accompanied by significant oxygen quenching. Our comprehensive photophysical analysis revealed that while DMAc-sFL-PN functions as a conventional fluorescent emitter in dilute solution, it exhibits distinct TADF characteristics upon incorporation into solid-state thin films. These findings suggest an environment dependent modulation of exciton dynamics. Such insights into the specific emission mechanisms are expected to contribute to the theoretical design of next-generation TADF materials capable of minimizing exciton-exciton annihilation.