Green TADF emitters based on adamantane-substituted acridine donor/diphenyl ketone acceptor in D-A and D-A-D systems

IF 4 3区材料科学 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Synthetic Metals Pub Date : 2025-01-14 DOI:10.1016/j.synthmet.2025.117831

Aziz Khan , Yu-Yang Ma , Sarvendra Kumar , Shijie Ge , Man-Keung Fung , Tim Leydecker , Zhiming Wang

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引用次数: 0

Abstract

The strategic change in the basic skeleton from donor-acceptor (D-A) to donor-acceptor-donor (D-A-D) to achieve an efficient external quantum efficiency (EQE) as well as high thermal stability is an invitation to develop new materials for organic light emitting diodes (OLED). In this way, adamantane-substituted acridine donor-based emitters, AA-DPK and AA-DPK-AA were developed for green thermally activated delayed fluorescence (TADF) emission. Moreover, the diphenylketone unit was used as an acceptor. The photophysical properties were explored and exhibited the dual emission characters, involving one emission from local or weak and other from strong intramolecular charge transfer (ICT) mechanism. Besides, the PL results exhibited the exact emission peaks not only in solution but also in OLED devices for AA-DPK and AA-DPK-AA molecules with dual fluorescence emission (DFE) nature in solution, which could be ascribed to quasi axial conformation (QAC) and quasi equatorial conformation (QEC). OLED devices using AA-DPK and AA-DPK-AA molecules as emitters with a widely used host material, 1,3-Bis(N-carbazolyl)benzene (mCP) exhibited green electroluminescence with higher EQEs of 8.5 % and 17 %, respectively. The AA-DPK-AA molecule demonstrated a two-fold improvement not only in EQEs and other parameters but also in thermal stability and photoluminescence quantum yield (PLQY). These enhancements contribute to the molecule's stability in OLEDs, resulting in low efficiency roll-off and high overall efficiency.

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来源期刊

Synthetic Metals 工程技术-材料科学：综合

CiteScore

8.30

自引率

4.50%

发文量

189

审稿时长

33 days

期刊介绍： This journal is an international medium for the rapid publication of original research papers, short communications and subject reviews dealing with research on and applications of electronic polymers and electronic molecular materials including novel carbon architectures. These functional materials have the properties of metals, semiconductors or magnets and are distinguishable from elemental and alloy/binary metals, semiconductors and magnets.