Filip Podjaski
Dr Filip Podjaski
Royal Society University Research Fellow
Research in the Podjaski group targets better understanding and control of emerging bifunctional materials that combine light absorption and energy storage intrinsically, through redox modifications involving the material itself and its environment. Such “photocharging materials” open the route to disruptive solar energy conversion technologies, including
- next generation photo-batteries, enabling to use the energy of light electrically on demand (and not only when light is available)
- light-driven information processing and storage, due to efficient light-matter interactions and memristive properties
Our focus lies on using porous, organic based semiconductors that can exhibit photocharging in natural (e.g. sea water based) environments. Their advantages are 1) the earth abundance of both, the material and electrolyte systems, enabling broad & cost-effective applications, and 2) their bottom-up synthetic tunability, allowing for tailoring structure-property-relations iteratively with our collaborators.
Illustration of photo-intercalation principle for photocharging, on the porous organic-based semiconductor K-PHI (from Adv. Energy Mater. 2021, 11, 2003049)
Besides functional material understanding, we explore materials’ behaviour in heterojunctions and device architecture, to bring fundamental research to real world applications.
To provide insights into environmentally sensitive material and device properties, we employ various photo-electrochemical techniques in our tailored setups, and couple them to operando time-resolved optical spectroscopies. As such, we map light-matter interactions, their modifications and process limitations on the entire time scale relevant for operation. From sub-picoseconds to hours, we account for the entire process chain including light absorption, exciton dissociation, charge generation and stabilization, their transport and transfer, their redox interactions and accumulation properties.
For these purposes, we develop operando measurement approaches, equipment and models, including the probing of physical parameters on ultrafast time scales with the Terahertz group at National Physical Laboratory (NPL, Teddington, UK).
