Our Research
The photochemistry and photophysics that drive energy flow within molecules are driven by electronic and nuclear motions. For this reason, we use ultrafast (femtosecond) spectroscopy techniques to probe these motions.
The systems we study and why we study them
Biomimeticsunscreens
Nature has had millions of years head-start on developing molecules to protect against excessive UV radiation exposure. Our goal here is to understand photoprotection mechanisms in natural sunscreens including those derived from plants and microbial species. We can then use this knowledge to develope biomimetic (next generation) sunscreens that are safer to humans and the environment
Molecular heaters
The ability to control how molecules convert photon energy to heat energy can have enormous impact on the agro industries and, therefore, food security. Our goal, through our EU Consortium (BoostCrop) is to develop a foliar spray containing molecular heaters. Once these are deposited on crops, they can absorb UV radition and conver this to heat. In so doing, this provides protection to crops against frost damage
Diamond defects
Atomic-scale defects can control the exploitable optoelectronic performance of crystalline materials, and several point defects in diamond are emerging functional components for a range of quantum technologies. By mapping out, energy relaxation pathways (multiphonon relaxation processes and anharmonic coupling) these can provide new routes to quantify and probe atomic-scale defects
Other systems
Fuelled by our interest in working with other groups, we study a range of other light absorbing molecular systems including photochemotherapy agents and photocatalysts. Photochemotherapy agents provide site-specific control for cancer treatment. Unravelling how these agents (transition metal complexes), respond at the very early stages of light absorption is a powerful tool for designing more efficious photochemotherapy agents
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How this all works
Pump-probe spectroscopy
Be it biomimetic sunscreens, molecular heaters or any other system we are studying, we need to photoexcite the system and then monitor how the system evolves over time. To do this, we use a combination of techniques. For the gas-phase, we use time-resolved ion-yield (TR-IY) or time-resolved photoelectron spectroscopy (TR-PES). For the solution and solid state, we us transient electronic absortion spectroscopy (TEAS) and transient vibrational absorption spectroscopy (TVAS). Further details of these approaches can be found in our papers.
Synthetic approaches
It is important to say at the outset that we are not a synthesis group. We rely on our incredibly talented collaborators to provide us with samples of molecules to be studied using pump-probe spectroscopy. Notable examples include Professor Florent Allais and his team at AgroParisTech whom we have collaborated for many years now on plant sunscreens and, more recently, Professors Diego Sampedro at the Universidad de La Rioja and Chris Corre at the University of Warwick, who we work with on microbial sunscreens.
Thory and computation
Over the years, we have benefitted immensely from numerous collaborations with theory groups. Theory is vitally important in interpreting our time-resolved data as well as suggesting new avenues of research. For this reason, we continue to work with theory groups and have even begun to have resident early career researchers in the group that are theeory based!!!
