Light-induced injection of hot carriers from gold nanoparticles to carbon wire bundles

TL;DR

This study demonstrates that laser illumination near plasmon resonance in gold nanoparticles enhances tunneling current in carbon wire bundles by injecting hot carriers, with potential applications in photonics and energy devices.

Contribution

It reveals a novel light-induced hot carrier injection mechanism from gold nanoparticles to carbon wires, enabling control of tunneling currents for optoelectronic applications.

Findings

Enhanced tunneling current under laser illumination near plasmon resonance.

Asymmetry in current-voltage characteristics indicating Schottky-like behavior.

Decreased junction resistance with increased optical pumping intensity.

Abstract

We observed a light-induced enhancement of the tunneling current propagating through an array of parallel carbon chains anchored between gold nanoparticles (NPs). In the presence of laser radiation characterized by a wavelength close to the plasmon resonance of the NPs, the current-voltage characteristics of carbon bundle tunnelling junctions demonstrate a pronounced asymmetry between positive and negative bias values. Such an asymmetry is typical for a Schottky junction, in general. The resistance of the tunnel junction decreases with the increase of the optical pumping intensity. We associate the observed effect with an injection of `hot' carriers created in Au NPs due to the decay of the surface plasmons accompanied by the charge transfer to the carbon bundles. The observed phenomenon can be used for non-resonant excitation of excitonic states in low-dimensional carbon-based structures for single-photon emission, as well as for photovoltaic applications.