Free-Standing Monolayered Metallic Nanoparticle Networks as Building Blocks for Plasmonic Nanoelectronic Junctions.

The effective coupling of optical surface plasmons (SPs) and electron transport in a plasmonic-electronic device is one of the fundamental issues in nanoelectronics and the emerging field of plasmonics, and offer promise in providing a solution to next generation nanocircuits in which all coupling is in the near field. Attempts toward this end, however, are limited because of the integration challenge to compatible nanodevices. To date, direct electrical detection of SP-electron coupling from metallic nanostructures alone are not reported, and thus it remains a great experimental challenge. In this paper, we succeed in preparing a new suspended-film-type nanoelectronic junction, in which free-standing 2D fractal nanoparticle networks act as plasmonically active nanocomponents. Direct electrical detection of optical collective SPs was evidenced by photocurrent response of the junction upon illumination. Room-temperature I-V characteristics, differing from nonlinear to Ohmic behaviors, are found to be sensitive to the nanometer-scale morphology changes of the nanomembranes. The finding and approach may enable the development of advanced plasmonic nanocircuits and new nanoelectronics, nanophotonics, and (solar) energy applications.