Journal
JOURNAL OF PHYSICAL CHEMISTRY A
Volume 119, Issue 14, Pages 3415-3418Publisher
AMER CHEMICAL SOC
DOI: 10.1021/acs.jpca.5b02253
Keywords
-
Funding
- Idemitsu Kosan Co., Ltd.
- CREST grant from JST
- MEXT [2610088]
- Network Joint Research Center for Materials and Devices
- Grants-in-Aid for Scientific Research [26410088] Funding Source: KAKEN
Ask authors/readers for more resources
The spin sublevel dynamics of the excited triplet state in thermally activated delayed fluorescence (TADF) molecules have not been investigated for high-intensity organic light-emitting diode materials. Understanding the mechanism for intersystem crossing (ISC) is thus important for designing novel TADF materials. We report the first study on the ISC dynamics of the lowest excited triplet state from the lowest excited singlet state with charge transfer (CT) character of TADF molecules with different external quantum efficiencies (EQEs) using time resolved electron paramagnetic resonance methods. Analysis of the observed spin polarization indicates a strong correlation of the EQE with the population rate due to ISC induced by hyperfine coupling with the magnetic nuclei. It is concluded that molecules with high EQE have an extremely small energy gap between the (CT)-C-1 and (CT)-C-3 states, which allows an additional ISC channel due to the hyperfine interactions.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available