Photonic contributions to the Seebeck (thermoelectric) effect

We report clear, spatially correlated photo-voltage generation in photonically engineered Au nanostructure devices. Although previous studies attribute photo-induced currents in single-metal nanostructures to the photothermoelectric (PTE) effect, our devices were designed to minimize purely electronic influences such as geometry, adsorbents, and impurities. Instead, our data support a mechanism in which photonic states couple to the electronic bath, altering the Seebeck coefficient via electromagnetic interactions. These findings reveal direct links between photonic and electronic properties in plasmonic metals and suggest that a plasmonic or photonic mechanism better explains the observed photocurrent than traditional PTE models. Our results offer new insight into light–electron interactions in metals, with potential implications for sensing and power conversion applications.