Relaxation dynamics in covalently bonded organic monolayers on silicon

TL;DR

This study investigates the dynamic electrical behavior of silicon-molecular monolayer-metal junctions, identifying key relaxation processes and proposing an equivalent circuit model to enhance device simulation and optimization.

Contribution

It introduces a small signal equivalent circuit model for molecular devices, capturing relaxation and defect effects, applicable to various molecular monolayers.

Findings

Identified dipolar relaxation and defect contributions in admittance data.

Proposed an equivalent circuit model for device simulation.

Results applicable to other molecular monolayers.

Abstract

We study the dynamic electrical response of a silicon-molecular monolayer-metal junctions and we observe two contributions in the admittance spectroscopy data. These contributions are related to dipolar relaxation and molecular organization in the monolayer in one hand, and the presence of defects at the silicon/molecule interface in the other hand. We propose a small signal equivalent circuit suitable for the simulations of these molecular devices in commercial device simulators. Our results concern monolayers of alkyl chains considered as a model system but can be extended to other molecular monolayers. These results open door to a better control and optimization of molecular devices.