Improving reverse intersystem crossing in exciplex-forming hosts by introducing heavy atom effect
| Autor: | Tianyu Huang, Luming Duan, Song Xiaozeng, Minghan Cai, Deqiang Zhang |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Materials science
Renewable Energy Sustainability and the Environment Materials Science (miscellaneous) Energy Engineering and Power Technology 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology Photochemistry Excimer 01 natural sciences Fluorescence 0104 chemical sciences Fuel Technology Intersystem crossing Nuclear Energy and Engineering Atom 0210 nano-technology Order of magnitude Diode Common emitter |
| Zdroj: | Materials Today Energy. 21:100705 |
| ISSN: | 2468-6069 |
| DOI: | 10.1016/j.mtener.2021.100705 |
| Popis: | A fast reverse intersystem crossing rate (kRISC) is an ongoing pursuit for exciplex-forming host with thermally activated delayed fluorescence (TADF) for improved performances of organic light-emitting diodes. However, design rules regarding the development of exciplex with a high kRISC are still elusive. Here, the influence of heavy atom effect on kRISC of exciplex is investigated with bromine (Br)-substituted acceptors. It is proved that heavy atom effect induced by Br atom can enhance the spin-orbital coupling of exciplex systems and thus promote the kRISC process of exciplex. Compared with the reference one (kRISC of 5.4 × 105 per second), Br-containing exciplex exhibits an increased kRISC by almost an order of magnitude, being 4.56 × 106 per second. Based on those exciplex-forming hosts, devices based on a conventional fluorescent emitter and a TADF emitter are fabricated, and it is observed that the faster the RISC process of exciplex-forming host is, the higher the device efficiency can be obtained. Those results here should provide an effective strategy to accelerate the kRISC of exciplex-forming host for advanced device performances. |
| Databáze: | OpenAIRE |
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