Efficient management of excitons in red and white organic light-emitting diodes by employing blue thermally activated delayed fluorescent emitter based acridine/sulfone derivative as the host
Ziqi Wang, Heng Zhang, Zongtao Wang, Bo Zhao, Liuqing Chen, Jie Li, Hua Wang, Yuying Hao, Wenlian Li
Index: 10.1016/j.orgel.2018.03.031
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Abstract
Highly efficient red and white organic light-emitting diodes (OLEDs) employing blue thermally activated delayed fluorescent (TADF) emitter of mSOAD based acridine/sulfone derivative as the host are realized by efficient management for singlet and triplet excitons. The red OLEDs reach a high maximum current efficiency, power efficiency and EQE of 32.7 cd A−1, 31.0 lm W−1 and 20.3%, respectively. And the white OLEDs with different dopant concentrations exhibit ultra-high color stability of ±(0.008, 0.001), ±(0.000, 0.003) and ±(0.002, 0.005), respectively. Meantime, the high efficiencies are also achieved with maximum current efficiencies, power efficiencies and EQEs of 28.2–32.0 cd A−1, 26.3–30.5 lm W−1 and 12.2–17.4%, respectively. The analysis of energy level and transient decay characteristics demonstrate the excellent device performances are mainly stemmed from the sufficient confinement for charges and excitons and efficient energy transfer from the TADF host to dopant.