Plasmoelectric Potential Mapping of a Single Nanoparticle

Abstract

The plasmoelectric potential effect, based on all-metal nanostructures, is a newly discovered plasmon-induced photoelectric converting mechanism. In this work, we have experimentally demonstrated that gold and silver nanoparticles exhibit opposite plasmoelectric potentials under the same excitation source, depending on their distinct surface plasmon resonance (SPR) frequencies. Three-dimensional mapping of plasmoelectric potentials on gold and silver nanoparticles depicts height-related surface potential information as well as the charge density evolution process down to the single nanoparticle level with Kelvin Probe Force Microscopy (KPFM). Upon employing a statistical method, the quantitative plasmoelectric potential is obtained. Under the power intensity of 5.4 mW/cm2, the maximum value of the plasmoelectric potential reaches −79 mV on the gold nanoparticle and 54 mV on silver nanoparticles. Finally, our work may provide guidance to the understanding of plasmoelectric potential on the single nanoparti...