Extreme sensitivity of plasmon drag to surface modification

Abstract

Abstract Giant enhancement of photocurrents in plasmonic structures (plasmon drag effect) provides opportunities for compact electric monitoring of plasmonic effects, and thus is promising for plasmonic-based sensing applications. In the experiment, we measure photoinduced electric signals in flat and profile-modulated systems, and test their sensitivity to small changes of the local dielectric environment, such as a presence of Langmuir–Blodgett monolayers at the metal surface. We show that the addition of a stearic acid monolayer leading to a small shift in plasmon resonance conditions can be ultimately resolved with electrical measurements as the switching in the photovoltage polarity.