Plasmoelectric potentials in Au nano-hole arrays
The resonant plasmonic properties of metallic nanostructures depend strongly on charge carrier density. Stemming from this dependence, we report a theoretical framework and provided experimental evidence for a 'plasmoelectric effect', a newly described mechanism for generating electrochemical potentials in plasmonic nanostructures. Systematic electrical and optical characterization of Au nano-hole arrays shows that the magnitude and sign of the plasmoelectric potential depends on the frequency difference between the plasmon resonance and incident narrowband radiation. Our findings guide the development of solid-state power conversion devices based on the plasmoelectric effect, as our samples generate electrochemical potentials 1000x larger than comparable thermocouples.