Symposium 1: Functional Metastructures and Nanomaterials: Properties, Fabrication and Modeling V

14:00 Invited talk : Developing semiconductor and plasmonic nanostructures for photovoltaic and photocatalytic applications

Dongling Ma

Institut National de la Recherche Scientifique (Canada)

The synthesis of near infrared (NIR) PbS and PbS@CdS core-shell quantum dots (QDs), and Au and Ag plasmonic nanostructures and their interesting optical properties will be presented first. Their hybridization with other nanomaterials or integration into different devices will also be introduced, which has led to enhanced power conversion efficiency of solar cells or improved catalytic activity in photocatalysis.
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14:20 Invited talk : Plasmon-Enhanced Solar Energy Conversion by Semiconductor-Metal Heterojunctions

Nianqiang Wu

West Virginia University (USA)

This talk will give a brief introduction to the history of plasmon-enhanced solar energy harvesting. This presentation will discuss the underlying mechanisms of plasmon-enhanced charge separation in the semiconductor. Also, this talk will demonstrate the plasmonic metal-semiconductor heterojunction for solar energy conversion.
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14:40 Invited talk : Prolonged Hot Electron Dynamics in Plasmonic-Metal/Semiconductor (Au/TiO2) Heterostructures with Implications for Solar Photocatalysis

Wei David Wei

University of Florida (USA)

Here we demonstrate the merits of augmenting traditional photoelectrochemical cells with plasmonic nanoparticles to satisfy these daunting photocatalytic requirements. Electrochemical techniques were employed to elucidate the mechanics of plasmon-mediated electron transfer within Au/TiO2 heterostructures under visible light irradiation in solution. Significantly, we discovered that these transferred electrons displayed excited-state lifetimes two orders of magnitude longer than those of electrons photogenerated directly within TiO2 via UV excitation. These long-lived electrons further enable visible-light-driven H2 evolution from water.
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15:00 : Hot Plasmonic Electrons, Heat Generation and Transparency Windows in Hybrid Nanostructures

Alexander Govorov

Ohio University (USA)

We investigate the effects of generation of heat and hot plasmonic carriers in metal nanostructures. The problem of heat release from optically-excited plasmonic nanocrystals is treated classically whereas the hot electron problem is calculated using the quantum mechanical approach based on the equation of motion for the density matrix. The energy distribution of optically-excited plasmonic carriers is very different in metal nanocrystals with large and small sizes.
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15:15 Invited talk : Electronic read-out of color centers via non-radiative energy transfer

Alexander Holleitner

Technische Universitat Munchen (Germany)

On the nanometer scale, non-radiative energy transfers have an efficiency close to unity. We describe how such a transfer can be used to electronically read-out color centers such as nitrogen vacancy centres in diamond. The read-out is achieved by a graphene layer located only a few nanometers away from the diamond. Via the non-radiative energy transfer, additional charge carriers are generated in the graphene, which are detected as an ultrafast current signal.
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