Group Photo at the Advanced Photon Source at Argonne National Lab, Fall 2017. From left to right:  Renske van der Veen, Cecilia Gentle, Allan Sykes, Tyler Haddock.

The conversion of light energy into chemical energy is a topic of uttermost importance in today's world. Among the general goals is to develop materials that can efficiently convert and store energy from the sun, or nanomaterials that can be rapidly switched between two states allowing them to be used in data storage devices. A fundamental understanding of the photophysical processes involved in light-energy conversion is prerequisite for developing such new materials with desired properties. In our lab we study the atomic-scale mechanisms of light-induced processes pertinent to photoswitching, photovoltaics and photocatalysis.

Our research focuses on several types of light-sensitive (molecular) materials: (i) switchable metal-organic complexes, (ii) functional nanomaterials relevant to photocatalysis, and (iii) photovoltaic materials. We would like to understand how the energy contained in a photon is channeled onto pathways and into states that can be used for specific functions.

 

How fast and efficient are excited-state relaxation processes and how do electronic and structural degrees of freedom couple?

We employ a variety of ultrafast spectroscopic and microscopic methods with time resolutions ranging from femtoseconds (fs) to nanoseconds (ns). The time resolution is based on the pump-probe principle, in which a short laser pulse excites the sample, while a short probe pulse (laser, X-rays, or electrons) takes a snapshot of the ongoing dynamics at later time delays.