February 17th, 2017 ALEXANDER BLOCK Molecular Nanophotonics

ALEXANDER BLOCK: Watching Energy Flow with Transient Absorption Microscopy

The migration of excited state energy, whether described as resonance energy transfer over multiple pigments or the diffusion of excitons in semiconductor materials, is a crucial mechanism in both natural photosynthesis as well as photovoltaics.

In this seminar I will present experimental details of an apparatus, a transient absorption microscope, which can map the flow of excited state energy over nanometric distances on (sub-)picosecond timescales and opens a window toward direct observations (ultra-slow-motion videos!) of otherwise indirectly studied effects in both natural and artificial light-harvesting dynamics.

*After the Seminar a NanoFabrication labtour will be held.

RENWEN YU: 'Nonlinear Plasmonic Sensing with Nanographene'

We identify a new mechanism revealing the presence of individual molecules through the radical changes they induce in the optical response associated with graphene plasmons. Specifically, a strong second-harmonic signal from nanostructured graphene emerges due to a redistribution of conduction electrons produced by interaction with the analyte molecules.

PhD Seminar, February 17, 2017, 17:00. Seminar Room