Interfacial TADF Exciplex as a Tool to Localise Excitons, Improve Efficiency and Increase OLED Lifetime

Colella, Marco; Pander, Piotr Henryk; Pereira, Daniel De Sa; Monkman, Andrew P.

Abstract

In this work, we employ a TADF exciplex formed between the emissive layer (EML) host, 26DCzPPy, and the electron transport layer (ETL), PO-T2T at the interface between the EML and the ETL to improve the stability and efficiency of a phosphorescence OLED based on Ir(dmpq)2acac. We show that the presence of the TADF exciplex at the EML-ETL interface induces an efficient localisation of the recombination zone which is confined within the 5 nm thick EML. Furthermore, the TADF exciplex allows harvesting of the holes and electrons that piled-up at the EML-ETL interface and transfer the resultant excited state energy to the phosphorescent emitter through Förster and/or Dexter energy transfer. This approach effectively improves the LT90 of devices from <1 min to 6 h by limiting recombination processes outside of the 5 nm EML.

Citation

Colella, M., Pander, P. H., Pereira, D. D. S., & Monkman, A. P. (2018). Interfacial TADF Exciplex as a Tool to Localise Excitons, Improve Efficiency and Increase OLED Lifetime. ACS Applied Materials and Interfaces, 10(46), 40001-40007. https://doi.org/10.1021/acsami.8b15942

• Journal Article Type: Article
• Acceptance Date: Nov 1, 2018
• Online Publication Date: Nov 1, 2018
• Publication Date: Nov 1, 2018
• Deposit Date: Nov 6, 2018
• Publicly Available Date: Nov 1, 2019
• Journal: ACS Applied Materials and Interfaces
• Print ISSN: 1944-8244
• Electronic ISSN: 1944-8252
• Publisher: American Chemical Society
• Peer Reviewed: Peer Reviewed
• Volume: 10
• Issue: 46
• Pages: 40001-40007
• DOI: https://doi.org/10.1021/acsami.8b15942
• Public URL: https://durham-repository.worktribe.com/output/1314079