Stepwise Charge/Energy Transfer in MR-TADF Molecule Doped Exciplex for Ultralong Persistent Luminescence Activated with Visible Light.
Pengfei JinXiaofang WeiBaipeng YinLixin XuYunlong GuoChuang ZhangPublished in: Advanced materials (Deerfield Beach, Fla.) (2024)
Organic long-persistent luminescence (OLPL), which relies on energy storage for delayed light emission by the charge separation state, has attracted intense attention in various optical applications. However, charge separation (CS) is efficient only under ultraviolet excitation in most OLPL systems because it requires a driving force from the large energy difference between the local excited (LE) and charge transfer (CT) states. In this study, we incorporate a multi-resonance thermally activated delayed fluorescence (MR-TADF) molecule into an exciplex system to achieve efficient OLPL in a composite material activated by visible light via a stepwise charge/energy transfer process. The enhanced absorption of the composite material facilitated a 10-fold increase in the duration of the OLPL, which can last for several hours under visible light excitation. The excited state of the MR-TADF molecule tends to charge transfer to the acceptor, followed by energy transfer to the exciplex, which benefits from the small difference between the LE and CT states owing to the inherent CS characteristics of the opposing resonance effect. Afterglow displays of these composite materials were fabricated to demonstrate their considerable potential in encryption patterns and emergency lights, which take advantage of their excellent processability, visible light activation, and tunable luminescence properties. This article is protected by copyright. All rights reserved.
Keyphrases
- energy transfer
- visible light
- contrast enhanced
- light emitting
- quantum dots
- solar cells
- magnetic resonance imaging
- magnetic resonance
- computed tomography
- dual energy
- image quality
- emergency department
- healthcare
- public health
- liquid chromatography
- positron emission tomography
- single molecule
- high resolution
- human health
- high speed
- pet ct