Electron cotunneling transport in gold nanocrystal arrays

Abstract

We describe current-voltage characteristics I(V) of alkyl-ligated gold nanocrystals $\sim 5nm$ arrays in long screening length limit. Arrays with different alkyl ligand lengths have been prepared to tune the electronic tunnel coupling between the nanocrystals. For long ligands, electronic diffusion occurs through sequential tunneling and follows activated laws, as function of temperature $\sigma \propto e^{-T_0/T}$ and as function of electric field $I\propto e^{-{\mathcal{E}}_0/\mathcal{E}}$. For better conducting arrays, i.e. with small ligands, the transport properties crossover to the cotunneling regime and follows Efros-Shklovskii laws as function of temperature $\sigma \propto e^{-(T_{ES}/T{)}^{1/2}}$ and as function of electric field $I\propto e^{-({\mathcal{E}}_{ES}/\mathcal{E}{)}^{1/2}}$. The data shows that electronic transport in nanocrystal arrays can be tuned from the sequential tunneling to the cotunneling regime by increasing the tunnel barrier transparency.

References in corpus (3)

• Percolating through networks of random thresholds: Finite temperature electron tunneling in metal nanocrystal arrays
• Sequential tunneling and inelastic cotunneling in nanoparticle arrays
• Electronic correlations and disorder in transport through one-dimensional nanoparticle arrays

Cited by in corpus (5)

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• Competition of the Coulomb and hopping based exchange interactions in granular magnets
• Coulomb gap triptychs, $\sqrt{2}$ effective charge, and hopping transport in periodic arrays of superconductor grains
• Coulomb gap triptych in a periodic array of metal nanocrystals