Quantifying Exciton Annihilation Effects in Thermally Activated Delayed Fluorescence Materials

Kalyani Thakur, Bas Zee, Gert‐Jan A. H. Wetzelaer, Charusheela Ramanan, Paul W. M Blom

Research output: Contribution to JournalArticleAcademicpeer-review

Abstract

Important parameters for the design and performance of thermally activated delayed fluorescence (TADF) emitters are the forward and reverse intersystem crossing rates between singlet and triplet states. The magnitude of these rates is determined from the prompt and delayed transient photoluminescence decay. It is demonstrated that this photoluminescence decay strongly depends on the initial photoexcited population density due to exciton–exciton annihilation processes. By kinetic modeling of the power-dependent time-resolved photoluminescence of the TADF emitter 9,10-bis(4-(9H-carbazol-9-yl)-2,6-dimethylphenyl)-9,10-diboraanthracene (CzDBA), singlet–triplet annihilation and triplet–triplet annihilation are identified as the main loss processes with rate constants in the order of 10−17 m3 s−1. Neglecting these quenching processes leads to erroneous estimates of the (reverse) intersystem crossing rates.
Original languageEnglish
Article number2101784
Pages (from-to)2101784
JournalADVANCED OPTICAL MATERIALS
Volume10
Issue number3
DOIs
Publication statusPublished - 6 Dec 2021
Externally publishedYes

Funding

The authors would like to thank Kun-Han Lin for performing the quantum chemical calculations of the excited state energy levels. Open access funding enabled and organized by Projekt DEAL.

Fingerprint

Dive into the research topics of 'Quantifying Exciton Annihilation Effects in Thermally Activated Delayed Fluorescence Materials'. Together they form a unique fingerprint.

Cite this