Femtoseconds (and faster) are the natural timescale for the elementary electronic, ionic, vibrational, etc processes that lie at the core of many functional materials and devices. We're interested in probing and controlling nanoscale chemical dynamics in this regime—particularly for reactions that are not driven by light.
Ultrafast Science
At the heart of both the natural world and man-made devices lie chemical processes like electron-transfer, vibrational lattice relaxation and ion conduction. The timescale for any one of these events, at the microscopic level is around a million-billionths of a second (femtosecond). The macroscopic response of materials/devices we are used to, are as a result of many of these individual processes collectively building-up. Hence, if we want to rationally understand how the overall behaviour of systems emerges we need to be able to capture and control these individual steps. This is where we come in.
We are building and applying tools to probe and control chemistry on the fastest timescales. The beauty is that the core phenomena we are looking at are universal to almost all reactions. Hence, we can be fairly broad in the systems we study, knowing our observations could have impact for a large number of fields.
Advanced spectroscopy and microscopy tools
Central to our research is the development of advanced spectroscopy and microscopy tools for probing time-resolved chemical dynamics. We utilise radiation all the way from the X-ray regime to the visible, IR and THz (sometimes coupled with extreme magnetic fields, pressures and temperatures).
Whilst we (as a community) have developed a vast toolkit to examine light-driven processes, watching reactions that are traditionally not driven by light (e.g., organometallic catalysis), especially on femtosecond/picosecond timescales, remains impossible. Our goal is to breakthrough into this regime to follow everything from the individual steps in organic/inorganic catalytic cycles to non-equilibrium ion hopping.
A key step for us is going to be moving beyond the time-averaged picture in ultrafast spectroscopies, such that we can capture random events like picosecond ion hops in battery materials. At the same time we want to push the spatial resolution of methods. For transparent objects tools exist to image deeply into them, but for the highly/scattering absorbing systems, often encountered in materials chemistry, serious challenges remain.
Quantum nanomaterials and photonics
The properties of a material at the nanoscale often deviate from those in the bulk. This is especially true when the atoms are 'confined' to particular spatial dimensions.
We have mainly been studying how structural confinement alters the electronic and spintronic properties of 1D organic polymers & dyes, or 0D/2D inorganic semiconductors (nanocrystals/van der Waals materials).
We are still interested in the above but increasingly are looking at how we can use light to manipulate electronic/magnetic properties in such nanosystems. We are especially interested in playing with the 'nature' of light, e.g., photon-pair entanglement, optical confinement (polaritons) or photon orbital angular momentum states, to access and control hidden material properties.
Clean energy
Much of our work is motivated by ultimately designing new chemistries for clean energy generation, conversion and storage. We are agnostic to the exact materials and devices involved, and so study a wide-range of systems including: inorganic oxides for batteries and catalysis, organic polymers for photovoltaics or bioelectronics and photonic materials for novel computing paradigms.
We want to be able to bridge our fundamental insights with application, hence strive to develop spectroscopic/microscopic tools that can be applied while devices operate.
