Enhancing Reverse Intersystem Crossing via Secondary Acceptors: toward Sky-Blue Fluorescent Diodes with 10-Fold Improved External Quantum Efficiency
In: ACS Applied Materials & Interfaces, Jg. 11 (2019-01-04), S. 4185-4192
Online
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Zugriff:
How to simply but effectively facilitate reverse intersystem crossing (RISC) transition is always the key issue for developing high-performance thermally activated delayed fluorescence dyes. In this work, as a proof of concept, a feasible strategy named "acceptor enhancement" is demonstrated with a series of ternary blue emitters ( xCz mPO nTPTZ) using diphenylphosphine oxide (PO) as secondary acceptors. Compared with its PO-free binary analogue, such a simple introduction of PO groups in pCzPO2TPTZ dramatically enhances its RISC rate constant ( kRISC) by 10 times the level of ∼105 s-1, accompanied by RISC efficiency (ηRISC) of 92%, which further improves the triplet-to-singlet upconversion for effective triplet harvesting in its devices. As a result, on the basis of a trilayer device structure, pCzPO2TPTZ realized a state-of-the-art external quantum efficiency beyond 20% with a 10-fold improvement.
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Enhancing Reverse Intersystem Crossing via Secondary Acceptors: toward Sky-Blue Fluorescent Diodes with 10-Fold Improved External Quantum Efficiency
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Autor/in / Beteiligte Person: | Han, Chunmiao ; Wang, Zicheng ; Xu, Hui ; Duan, Chunbo ; Fan, Xuefeng ; Wei, Ying ; Li, Chenyu |
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Zeitschrift: | ACS Applied Materials & Interfaces, Jg. 11 (2019-01-04), S. 4185-4192 |
Veröffentlichung: | American Chemical Society (ACS), 2019 |
Medientyp: | unknown |
ISSN: | 1944-8252 (print) ; 1944-8244 (print) |
DOI: | 10.1021/acsami.8b18041 |
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