High-efficiency Hyperfluorescent White Light-emitting Diodes Based on High-concentration-doped TADF Sensitizer Matrices Spatial and Energy Gap Effects

Overview

Journal Chem Sci

Publisher Royal Society of Chemistry

Specialty Chemistry

Date 2022 Jan 21

PMID 35059164

Authors

Chunbo Duan

Ying Xin

Zicheng Wang

Jing Zhang

Chunmiao Han

Hui Xu

Affiliations

Soon will be listed here.

Abstract

Despite the success of monochromatic hyperfluorescent (HF) organic light-emitting diodes (OLEDs), high-efficiency HF white OLEDs (WOLEDs) are still a big challenge. Herein, we demonstrate HF WOLEDs with state-of-the-art efficiencies, featuring a quasi-bilayer emissive layer (EML) composed of an ultrathin (0.1 nm) blue fluorescence (FL) emitter (TBPe) layer and a layer of thermally activated delayed fluorescence (TADF) sensitizer matrix heavily doped with a yellow FL emitter (TBRb, 3%). Based on an asymmetric high-energy-gap TADF sensitizer host (PhCzSPOTz), such an "ultrathin blue emitting layer (UTBL)" strategy endowed the HF WOLEDs with a record power efficiency of ∼80 lm W, approaching the level of fluorescent tubes. Transient photoluminescence (PL) and electroluminescence (EL) kinetics demonstrate that the spatial separation of TBPe from the TADF sensitizer and TBRb, and the large energy gap between the latter two effectively suppress triplet leakage, in addition to suppressing triplet diffusion in the PhCzSPOTz matrix with anisotropic intermolecular interactions. These results provide a new insight into the exciton allocation process in HF white light-emitting systems.

Citing Articles

White Fluorescent Organic Light-Emitting Diodes with 100% Power Conversion.

Ding D, Wang Z, Duan C, Han C, Zhang J, Chen S Research (Wash D C). 2024; 2022:0009.

PMID: 39290967 PMC: 11407583. DOI: 10.34133/research.0009.

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