# Harnessing Quantum Capacitance in 2D Material/Molecular Layer Junctions for Novel Electronic Device Functionality

## TL;DR

This paper introduces a new electronic device using 2D materials and molecular layers that shows improved performance and novel behavior like negative resistance.

## Contribution

A novel device concept using quantum capacitance in 2D material/molecular layer junctions is introduced.

## Key findings

- The vc2Dmj diode exhibits NDR with a high peak-to-valley ratio at room temperature.
- Thermoelectric measurements and ab initio calculations reveal a hybridization effect between graphene and the molecular layer.
- Morphology optimization enhances device parameters for future electronic applications.

## Abstract

Two-dimensional (2D) materials promise advances in electronic devices beyond Moore’s scaling law through extended functionality, such as non-monotonic dependence of device parameters on input parameters. However, the robustness and performance of effects like negative differential resistance (NDR) and anti-ambipolar behavior have been limited in scale and robustness by relying on atomic defects and complex heterojunctions. In this paper, we introduce a novel device concept that utilizes the quantum capacitance of junctions between 2D materials and molecular layers. We realized a variable capacitance 2D molecular junction (vc2Dmj) diode through the scalable integration of graphene and single layers of stearic acid. The vc2Dmj exhibits NDR with a substantial peak-to-valley ratio even at room temperature and an active negative resistance region. The origin of this unique behavior was identified through thermoelectric measurements and ab initio calculations to be a hybridization effect between graphene and the molecular layer. The enhancement of device parameters through morphology optimization highlights the potential of our approach toward new functionalities that advance the landscape of future electronics.