High‐Performance Hot‐Exciton OLEDs via Fully Harvesting Triplet Excited States from Both the Exciplex Co‐Host and the TBRb Emitter

Abstract The high‐level reverse intersystem crossing (HL‐RISC, T2 → S1) process from triplet to singlet exciton, namely the “hot exciton” channel, has recently been demonstrated in the traditional fluorescent emitter of TBRb. Although it is a potential pathway to improve the utilization of non‐radia...

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Main Authors: Fuxian Wei, Jing Chen, Xi Zhao, Yuting Wu, Huiyao Wang, Xiaoli Chen, Zuhong Xiong
Format: Article
Language:English
Published: Wiley 2023-10-01
Series:Advanced Science
Subjects:
Online Access:https://doi.org/10.1002/advs.202303192
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author Fuxian Wei
Jing Chen
Xi Zhao
Yuting Wu
Huiyao Wang
Xiaoli Chen
Zuhong Xiong
author_facet Fuxian Wei
Jing Chen
Xi Zhao
Yuting Wu
Huiyao Wang
Xiaoli Chen
Zuhong Xiong
author_sort Fuxian Wei
collection DOAJ
description Abstract The high‐level reverse intersystem crossing (HL‐RISC, T2 → S1) process from triplet to singlet exciton, namely the “hot exciton” channel, has recently been demonstrated in the traditional fluorescent emitter of TBRb. Although it is a potential pathway to improve the utilization of non‐radiative triplet exciton energy, highly efficient fluorescent organic light emitting diodes (FOLEDs) based on this “hot exciton” channel have not been developed. Herein, high‐efficiency and low‐efficiency roll‐off FOLEDs are achieved through doping TBRb molecules into an energy‐level matched exciplex co‐host. Combining the low‐level RISC (LL‐RISC, EX3 → EX1) process in the exciplex co‐host with the HL‐RISC process of hot excitons in TBRb to fully harvest the triplet energy, a record‐high external quantum efficiency (EQE) of 20.4% is obtained via a proper Dexter energy transfer of triplet excitons, realizing the efficiency breakthrough from fully fluorescent material‐based OLEDs with TBRb as an end emitter. Furthermore, the fingerprint Magneto‐electroluminescence (MEL) as a sensitive measuring tool is employed to visualize the “hot exciton” channel in TBRb, which also directly verifies the effective energy confinement and the full utilization of hot excitons. Obviously, this work paves a promising way for further fabricating high‐efficiency TBRb‐based FOLEDs for lighting and flat‐panel display applications.
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spelling doaj.art-77973671bbd94b31b123e45f62d6bbe02023-10-18T06:07:54ZengWileyAdvanced Science2198-38442023-10-011029n/an/a10.1002/advs.202303192High‐Performance Hot‐Exciton OLEDs via Fully Harvesting Triplet Excited States from Both the Exciplex Co‐Host and the TBRb EmitterFuxian Wei0Jing Chen1Xi Zhao2Yuting Wu3Huiyao Wang4Xiaoli Chen5Zuhong Xiong6Chongqing Key Laboratory of Micro & Nano Structure Optoelectronics, School of Physical Science and Technology Southwest University Chongqing 400715 P. R. ChinaChongqing Key Laboratory of Micro & Nano Structure Optoelectronics, School of Physical Science and Technology Southwest University Chongqing 400715 P. R. ChinaChongqing Key Laboratory of Micro & Nano Structure Optoelectronics, School of Physical Science and Technology Southwest University Chongqing 400715 P. R. ChinaChongqing Key Laboratory of Micro & Nano Structure Optoelectronics, School of Physical Science and Technology Southwest University Chongqing 400715 P. R. ChinaChongqing Key Laboratory of Micro & Nano Structure Optoelectronics, School of Physical Science and Technology Southwest University Chongqing 400715 P. R. ChinaChongqing Key Laboratory of Micro & Nano Structure Optoelectronics, School of Physical Science and Technology Southwest University Chongqing 400715 P. R. ChinaChongqing Key Laboratory of Micro & Nano Structure Optoelectronics, School of Physical Science and Technology Southwest University Chongqing 400715 P. R. ChinaAbstract The high‐level reverse intersystem crossing (HL‐RISC, T2 → S1) process from triplet to singlet exciton, namely the “hot exciton” channel, has recently been demonstrated in the traditional fluorescent emitter of TBRb. Although it is a potential pathway to improve the utilization of non‐radiative triplet exciton energy, highly efficient fluorescent organic light emitting diodes (FOLEDs) based on this “hot exciton” channel have not been developed. Herein, high‐efficiency and low‐efficiency roll‐off FOLEDs are achieved through doping TBRb molecules into an energy‐level matched exciplex co‐host. Combining the low‐level RISC (LL‐RISC, EX3 → EX1) process in the exciplex co‐host with the HL‐RISC process of hot excitons in TBRb to fully harvest the triplet energy, a record‐high external quantum efficiency (EQE) of 20.4% is obtained via a proper Dexter energy transfer of triplet excitons, realizing the efficiency breakthrough from fully fluorescent material‐based OLEDs with TBRb as an end emitter. Furthermore, the fingerprint Magneto‐electroluminescence (MEL) as a sensitive measuring tool is employed to visualize the “hot exciton” channel in TBRb, which also directly verifies the effective energy confinement and the full utilization of hot excitons. Obviously, this work paves a promising way for further fabricating high‐efficiency TBRb‐based FOLEDs for lighting and flat‐panel display applications.https://doi.org/10.1002/advs.202303192dexter energy transferhot excitonmagneto‐electroluminescenceorganic light‐emitting diodereverse intersystem crossing
spellingShingle Fuxian Wei
Jing Chen
Xi Zhao
Yuting Wu
Huiyao Wang
Xiaoli Chen
Zuhong Xiong
High‐Performance Hot‐Exciton OLEDs via Fully Harvesting Triplet Excited States from Both the Exciplex Co‐Host and the TBRb Emitter
Advanced Science
dexter energy transfer
hot exciton
magneto‐electroluminescence
organic light‐emitting diode
reverse intersystem crossing
title High‐Performance Hot‐Exciton OLEDs via Fully Harvesting Triplet Excited States from Both the Exciplex Co‐Host and the TBRb Emitter
title_full High‐Performance Hot‐Exciton OLEDs via Fully Harvesting Triplet Excited States from Both the Exciplex Co‐Host and the TBRb Emitter
title_fullStr High‐Performance Hot‐Exciton OLEDs via Fully Harvesting Triplet Excited States from Both the Exciplex Co‐Host and the TBRb Emitter
title_full_unstemmed High‐Performance Hot‐Exciton OLEDs via Fully Harvesting Triplet Excited States from Both the Exciplex Co‐Host and the TBRb Emitter
title_short High‐Performance Hot‐Exciton OLEDs via Fully Harvesting Triplet Excited States from Both the Exciplex Co‐Host and the TBRb Emitter
title_sort high performance hot exciton oleds via fully harvesting triplet excited states from both the exciplex co host and the tbrb emitter
topic dexter energy transfer
hot exciton
magneto‐electroluminescence
organic light‐emitting diode
reverse intersystem crossing
url https://doi.org/10.1002/advs.202303192
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