Nonlinear Transport in Carbon Quantum Dot Electronic Devices: Experiment and Theory

TL;DR

This study explores the nonlinear electronic transport properties of carbon quantum dots embedded in epoxy, combining experimental measurements with a theoretical model to understand diverse conduction regimes at room temperature.

Contribution

It introduces a master equation model that accurately describes multiple transport regimes in CQD devices, highlighting the role of interactions and traps.

Findings

Observation of nonlinear I-V characteristics including Schottky, Coulomb blockade, and negative differential conductance.

Development of a theoretical framework matching experimental current-voltage data.

Demonstration of CQDs as versatile materials for 3D integrated electronics.

Abstract

Carbon quantum dots (CQDs) are a promising material for electronic applications due to their easy fabrication and interesting semiconductor properties. Further, CQDs exhibit quantum confinement and charging effects, which may lead not only to improved performances but also to devices with novel functionalities. Here, we investigate the electronic transport of CQDs embedded on epoxy polymer. Our samples are coupled to interdigitated electrodes with individually addressable microelectrodes. Remarkably, the current-voltage characteristics show strongly nonlinear regimes at room temperature, ranging from Schottky diode to Coulomb blockade and even negative differential conductance behavior. We propose a master equation theoretical framework which allows us to compute current curves that agree well with the observations. This model emphasizes the importance of interacting dots and electron traps in generating a cohesive picture that encompasses all transport regimes. Overall, our results suggest that CQDs constitute a versatile materials platform for 3D integrated electronic purposes.