Photonic Contributions to the Apparent Seebeck Coefficient of Plasmonic Metals

Abstract

Photo-induced charge transport in plasmonic metal nanostructures has garnered significant interest for applications in sensing and power conversion, yet the underlying mechanisms remain debated. Here, we report spatially correlated photovoltage generation in photonically engineered Au nanowires illuminated by focused, milliwatt-level laser excitation. Plasmonic nanodisk antennas placed adjacent to the nanowires created local variations in the photonic environment, resulting in clearly defined regions of enhanced photovoltage. Experimental results and simulations strongly support a thermally driven photothermoelectric (PTE) mechanism, where the local photonic structure modifies the intrinsic Seebeck coefficient of the metal, independent of other electronic structural factors. Our findings highlight photon-electron interactions as critical to the observed transport phenomena, suggesting photonic engineering as a viable strategy to systematically control and optimize thermoelectric performance.

References in corpus (6)

• Theory of surface plasmons and surface-plasmon polaritons
• Optical Rectification and Field Enhancement in a Plasmonic Nanogap
• Substantial local variation of Seebeck coefficient in gold nanowires
• Thermoelectric response from grain boundaries and lattice distortions in crystalline gold devices
• The Connection Between Plasmon Decay Dynamics and the SERS background: Inelastic Scattering from Non-Thermal and Hot Carriers
• Active tuning of plasmon damping via light induced magnetism