We are interested in understanding photo-induced excitation dynamics in colloidal semiconductor nanocrystals (NCs). These colloidal materials hold tremendous potential for low-cost processing and high-efficiency solar energy conversion. This is due to their size-tunable absorption thresholds and high photo-stability. In addition, some quantum confined NCs display an electron-hole pair generation phenomenon with greater than 100% quantum yield, called “multiple exciton generation” (MEG). These materials could be used to develop solar cells with efficiencies that exceed the 33.7% limiting value for conventional materials.
B.S.: Oxford University
Ph.D.: Cambridge University
Post-doc: National Renewable Energy Lab, Golden, Co
Post-doc: University of Toronto
We aim to develop models of the complex electronic interactions in nanoscale materials between intrinsic photo-generated states and the local environment.
To do this we combine efforts in:
- Nanocrystal synthesis: e.g. colloidal CdSe, CdTe, PbS and PbSe.
- Time-resolved spectroscopy: including time-correlated single photon counting, fluorescence correlation spectroscopy, fluorescence microscopy and transient absorption spectroscopy.
- Computational data analysis and development of semi-empirical excitation dynamics models.
Our current focus is on carrier trapping and light-induced charge transfer reactions in colloidal nanocrystals. We want to understand the processes that promote charge separation in these materials to enable development of new nanocrystal-based materials with greatly improved characteristics for photovoltaic applications.