Manipulating Carrier Recombination Dynamics Through Rational Dual‐Trap Engineering in Exciplex Heterojunction for High‐Performance OLEDs
Abstract
ABSTRACT While trap states are traditionally considered as performance‐limiting defects in organic light‐emitting diodes (OLEDs), this work presents a dual‐trap exciplex heterojunction system that strategically engineers trap states to enhance device performance. The tailored electron (4CzTPNBu in p‐type host) and hole (PO‐01 in n‐type host) traps are employed for interfacial bidirectional carrier capture synergistically without compromising carrier transport in the exciplex heterojunction system. This innovative design converts interfacial traps into immediate radiative trap‐assisted recombination (TAR) centers with significant expansion of exciton recombination zone, simultaneously preventing carrier transport imbalance and charge accumulation. The yellow OLEDs demonstrate cutting‐edge 33.9% external quantum efficiency (EQE), and 453.6 h operational lifetime (LT 90 at 1000 cd m −2 ) representing a ninefold enhancement over conventional architectures. Through ideality factor analysis complemented by single‐carrier device and transient electroluminescence studies, the fundamental charge transport physics and trap‐mediated dynamics are unraveled. Implementation of dual‐trap in narrow‐band hyperfluorescent systems also enables EQEs surpassing 36% and mitigated efficiency roll‐off, along with prolonged LT 90 of 178.7 h. The dual‐trap methodology successfully merges the advantages for twin emitters and achieves a win‐win scenario for efficiency and lifetime, providing a promising paradigm for future high‐performance OLED development.
Article Details
Authors (11)
Guohao Chen
Tong Wang
Zhihai Yang
Guangdong Basic Research Center of Excellence for Energy and Information Polymer Materials Institute of Polymer Optoelectronic Materials and Devices State Key Laboratory of Luminescent Materials and Devices South China University of Technology Guangzhou P. R. China
Zhizhi Li
Guangdong Basic Research Center of Excellence for Energy and Information Polymer Materials Institute of Polymer Optoelectronic Materials and Devices State Key Laboratory of Luminescent Materials and Devices South China University of Technology Guangzhou P. R. China
Shaofeng Chen
Guangdong Basic Research Center of Excellence for Energy & Information Polymer Materials Institute of Polymer Optoelectronic Materials and Devices State Key Laboratory of Luminescent Materials and Devices South China University of Technology Guangzhou P. R. China
Yuchen Jiang
Zijian Chen
State Key Laboratory of Fine Chemicals, Frontiers Science Center for Smart Materials, School of Chemical Engineering
Yu Fu
Mengke Li
Junji Kido
Guangdong Basic Research Center of Excellence for Energy and Information Polymer Materials Institute of Polymer Optoelectronic Materials and Devices State Key Laboratory of Luminescent Materials and Devices South China University of Technology Guangzhou P. R. China
Shi‐Jian Su
Guangdong Basic Research Center of Excellence for Energy and Information Polymer Materials Institute of Polymer Optoelectronic Materials and Devices State Key Laboratory of Luminescent Materials and Devices South China University of Technology Guangzhou P. R. China