Making Two Triplets from One Singlet Exciton: Research seminar with A/Prof Tak W. Kee

Making Two Triplets from One Singlet Exciton – Singlet Fission Yield of TIPS-Pentacene in a Polymer Matrix.

Singlet fission (SF) is a process by which a singlet exciton is dissociated to form two triplet excitons through a spin allowed process within a pair of molecules. SF is attracting significant research interest in renewable energy because it addresses a critical issue in single-junction solar cells – the efficiency is limited to ~ 33 %. SF solar cells can potentially minimise thermalisation of the initially prepared exciton, leading to a theoretical efficiency limit of 45 %.

In this presentation, recent results will be reported in understanding the mechanism of SF by employing an aqueous nanoparticle system in which an SF compound, TIPS-pentacene, is embedded in an inert, amorphous host polymer matrix.

Femtosecond time-resolved spectroscopy was used to study the TIPS-pentacene/host polymer nanoparticles. Results exhibit a strong dependence on intermolecular distance, indicating a control of energy migration and SF. Additionally, molecular dynamics and Monte Carlo simulations were used to model the experimental results.
This work reveals the roles of SF, energy migration and aggregation of TIPS-pentacene in the host polymer matrix, contributing to further understanding of SF mechanism.

About the speaker

Associate Professor Kee received his PhD from The University of Texas at Austin, USA in 2003.

From 2003 to 2006 he was postdoctoral associate at the National Institute of Standards & Technology (NIST), USA. From 2006, he has served as a Lecturer, Senior Lecturer and he is currently an Associate Professor at the University of Adelaide.

He is also the Chair of Division of Physical Chemistry of the Royal Australian Chemical Institute.

Tagged in Events, Chemical Engineering