Electronic transport in quasi-one-dimensional arrays of gold nanocrystals

TL;DR

This study investigates the electronic transport properties of ultra-narrow gold nanocrystal arrays, revealing nonlinear IV behavior, temperature sensitivity, and current fluctuations due to single-electron tunneling effects in quasi-one-dimensional structures.

Contribution

The paper demonstrates the fabrication of ultra-narrow, highly ordered gold nanocrystal arrays and characterizes their nonlinear transport behavior, highlighting differences from wider arrays and effects of temperature cycling.

Findings

Nonlinear power-law IV characteristics in narrow arrays

High temperature sensitivity of IV shape

Pronounced low-temperature current fluctuations

Abstract

We report on the fabrication and current-voltage (IV) characteristics of very narrow, strip-like arrays of metal nanoparticles. The arrays were formed from gold nanocrystals self-assembled between in-plane electrodes. Local cross-linking of the ligands by exposure to a focused electron beam and subsequent removal of the unexposed regions produced arrays as narrow as four particles wide and sixty particles long, with high degree of structural ordering. Remarkably, even for such quasi-one-dimensional strips, we find nonlinear, power-law IV characteristics similar to that of much wider two-dimensional (2D) arrays. However, in contrast to the robust behavior of 2D arrays, the shape of the IV characteristics is much more sensitive to temperature changes and temperature cycling. Furthermore, at low temperatures we observe pronounced two-level current fluctuations, indicative of discrete rearrangements in the current paths. We associate this behavior with the inherent high sensitivity of single electron tunneling to the polarization caused by the quenched offset charges in the underlying substrate.