Absence of scaling in transport through two-dimensional nanoparticle arrays

TL;DR

This study demonstrates that the traditional scaling hypothesis does not accurately describe electronic transport in disordered two-dimensional nanoparticle arrays, revealing a linear current-voltage relationship near the threshold instead.

Contribution

It challenges the prevailing scaling model for transport in nanoparticle arrays and proposes a linear dependence near the threshold voltage.

Findings

Linear current dependence on (V - V_T) near threshold

Scaling power-law fits yield inconsistent parameters

Traditional scaling models do not fit experimental data well

Abstract

We analyze the transport in disordered two-dimensional nanoparticle arrays. We show that the commonly used scaling hypothesis to fit the I-V curves does not describe the electronic transport in these systems. On the contrary, close to the threshold voltage V_T the current depends linearly on (V-V_T). This linear behavior is observed for at least five decades in (V-V_T). Fitting the I-V curves at larger voltages to a scaling power-law I \propto (V/V_T-1)^\xi results in fitting parameters which depend on the range of voltages used and in wrong values for V_T. Our results urge to change the picture of electronic transport in disordered nanoparticle arrays used in the last two decades.