Energy Transfer

Introduction

Life as we know it depends on the sun for survival. Light from the sun drives the biochemical processes of photosynthesis, upon which the world’s food supply relies. This energy, which is initially absorbed by specialized pigment-protein complexes, migrates along the complex in the form of excitons (electron-hole pairs) with very high quantum efficiency to a specialized region of the photosynthetic apparatus known as the reaction center. Much effort is now being directed in making biomimetic devices based on design principles used by nature, although this has proved a tremendously difficult task. It is not entirely clear the mechanistic reasons why excitons can migrate tens to hundreds of nanometers in natural photosynthetic systems, but only diffuse a few nanometers in organic semiconductors. We are interested in understanding the interplay between coherent and incoherent phenomena that govern that highly efficient exciton transport in natural systems and applying these principles to synthetic devices optimized for light harvesting and transport. We plan to design hybrid devices that incorporate pigments from natural systems but “wired” using lithographic techniques. Using tools inspired from magnetic resonance imaging and spectroscopy, we will follow the fate of excitons with sub-diffraction spatial resolution and femtosecond precision.

Figure 1:. Wavelike energy transport through a system of coupled dipoles. Quantum-,mechanical effects can increase the efficiency of transport or, alternatively, by being more robust to disorder than possible by purely classical means.

Experiments Coming Soon!!