Low-temperature cotunneling electron transport in photo-switchable molecule-nanoparticle networks

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Main Authors: Viero, Yannick, Guérin, David, Vuillaume, Dominique
Format: Preprint
Published: 2025
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author Viero, Yannick
Guérin, David
Vuillaume, Dominique
author_facet Viero, Yannick
Guérin, David
Vuillaume, Dominique
contents We report the temperature-dependent (4.2 - 300 K) electron transport properties (current-voltage) of photo-switchable two-dimensional arrays of gold nanoparticles (10 nm in diameter) functionalized by azobenzene derivatives. Under UV-light irradiation at 4.2 K, the azobenzene moieties are switched from the trans to cis isomers, leading to an increase of the current. In both conformations, at low temperature (< 77 K) and low voltage (< 1 V) the voltage- and temperature-dependent current behaviors show that electron cotunneling is the dominant transport mechanism. The number of cotunneling events Ncot slightly increases from ca. 1. 4 to 1.7 upon trans-to-cis isomerization of the azobenzenes. The nanoparticle Coulomb charging energy is not significantly modified (ca. 15 meV) by the azobenzene isomerization. This weak increase of Ncot is explained by the modest cis/trans current ratio (< 10) and the limited numbers of nanoparticle-molecule-nanoparticle junctions inserted between the two nanoscale electrodes (< 50 nm apart) connecting the network.
format Preprint
id arxiv_https___arxiv_org_abs_2506_05552
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Low-temperature cotunneling electron transport in photo-switchable molecule-nanoparticle networks
Viero, Yannick
Guérin, David
Vuillaume, Dominique
Mesoscale and Nanoscale Physics
We report the temperature-dependent (4.2 - 300 K) electron transport properties (current-voltage) of photo-switchable two-dimensional arrays of gold nanoparticles (10 nm in diameter) functionalized by azobenzene derivatives. Under UV-light irradiation at 4.2 K, the azobenzene moieties are switched from the trans to cis isomers, leading to an increase of the current. In both conformations, at low temperature (< 77 K) and low voltage (< 1 V) the voltage- and temperature-dependent current behaviors show that electron cotunneling is the dominant transport mechanism. The number of cotunneling events Ncot slightly increases from ca. 1. 4 to 1.7 upon trans-to-cis isomerization of the azobenzenes. The nanoparticle Coulomb charging energy is not significantly modified (ca. 15 meV) by the azobenzene isomerization. This weak increase of Ncot is explained by the modest cis/trans current ratio (< 10) and the limited numbers of nanoparticle-molecule-nanoparticle junctions inserted between the two nanoscale electrodes (< 50 nm apart) connecting the network.
title Low-temperature cotunneling electron transport in photo-switchable molecule-nanoparticle networks
topic Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2506.05552