Event Details

Join Dr Congrave - Royal Society University Research Fellow, Research Fellow in Chemistry at the University of Oxford - for a talk on NIR light. Also on Teams.

Materials that efficiently emit and absorb light in the near-infrared (NIR) are highly desirable across traditional scientific fields, with implications in areas such as bioimaging and electricity-light interconversion. It has been particularly challenging to develop highly luminescent NIR organic molecules because coupling to high frequency aromatic C–C stretching vibrations promotes non-radiative decay - the release of energy as heat, rather than light. Considering that organics must contain carbon atoms(!), the presence of these vibrations is intrinsic.

While we cannot remove the possibility of aromatic C–C stretches from organic molecules, perhaps we can just stop our excited state from coupling to them? In this talk I will discuss our recent efforts to develop design rules for decoupling the excited states of organics from C–C stretching vibrations to achieve efficient NIR emission. The concept of vibrational localisation will be demonstrated as both a diagnostic tool and a design solution.

Particularly, via our methodology we have been able to drastically improve the luminescence efficiency of complete NIR thermally activated delayed fluorescence materials from < 1% to ca.30%, which is especially interesting from the perspective of overcoming the high non-radiative voltage loss that currently plagues organic solar cells. The work combines synthetic organic and inorganic chemistry with physical chemistry, photophysics and spectroscopy.

Venue: Cavendish Colloquium Room (Faraday Complex) and via Teams – join here