| Project Detail |
Enhancing SWCNT emission through triplet functionalisation
Single-walled carbon nanotubes (SWCNTs) have unique optoelectronic properties thanks to their size and structure. Their high carrier mobility, chemical stability and narrow, tuneable near-infrared (NIR) emission make them ideal for NIR organic light-emitting diodes (OLEDs) and light-emitting transistors (LETs). However, their low emission efficiency is a hurdle towards their integration in these applications. With the support of the Marie Sklodowska-Curie Actions programme, the C-BRIGHT project aims to improve SWCNT emission efficiency by filling their hollow core and functionalising their outer wall with triplet sensitisers. Using optically detected magnetic resonance, researchers will study the impact on triplet exciton photophysics. The functionalised SWCNTs will then be integrated into LETs and OLEDs to explore new possibilities for efficient NIR devices in medical and biosensing fields.
Single-walled carbon nanotubes (SWCNTs) possess uniquely diverse optoelectronic properties that depend critically on their exact diameter and chiral structure. Their quasi one-dimensional structure, high carrier mobility, photochemical and mechanical stability, combined with extremely narrow and tunable emission in the near-infrared (NIR), make them interesting candidates as active material in NIR organic light-emitting diodes (OLEDs) or light-emitting transistors (LETs). The integration of SWCNTs in OLEDs and LETs has so far been limited by their typically low intrinsic emission quantum efficiency. Enhancing the SWCNTs emission efficiency, therefore, requires an in-depth understanding of the complex exciton photophysics, in particular, that of the multiple dark excitons. In this project, we will investigate the filling of the SWCNTs inner hollow core combined with functionalizing their outer wall with particular triplet sensitizers. This provides two orthogonal degrees of freedom to enhance intersystem crossing to the triplet state and at the same time to make the triplet excitons bright, aiming for highly efficient SWCNTs triplet phosphorescence as a NIR emission source. To investigate the particular effect of the functionalization on the triplet exciton photophysics, we will make use of a unique technique that combines optical spectroscopy with the spin-selective magnetic resonance technique, namely optically-detected magnetic resonance (ODMR). Finally, as a proof-of-principle, these functionalized SWCNTs will be integrated in LETs and OLEDs. In operando characterization through, amongst others, electrically-detected magnetic resonance (EDMR) will be performed to determine the role of the spin-dependent electron-hole recombination processes in the devices, opening new avenues to highly emissive NIR-OLEDs/LETs, essential for a wide range of biomedical and biosensing applications. |
