Single-molecule electrical contacts on silicon electrodes under ambient conditions

Albert C Aragonès,Ismael Díez-Pérez,J Justin Gooding,Fausto Sanz,Nadim Darwish,Simone Ciampi

doi:10.1038/ncomms15056

Abstract

The ultimate goal in molecular electronics is to use individual molecules as the active electronic component of a real-world sturdy device. For this concept to become reality, it will require the field of single-molecule electronics to shift towards the semiconducting platform of the current microelectronics industry. Here, we report silicon-based single-molecule contacts that are mechanically and electrically stable under ambient conditions. The single-molecule contacts are prepared on silicon electrodes using the scanning tunnelling microscopy break-junction approach using a top metallic probe. The molecular wires show remarkable current–voltage reproducibility, as compared to an open silicon/nano-gap/metal junction, with current rectification ratios exceeding 4,000 when a low-doped silicon is used. The extension of the single-molecule junction approach to a silicon substrate contributes to the next level of miniaturization of electronic components and it is anticipated it will pave the way to a new class of robust single-molecule circuits.

Highlights

The ultimate goal in molecular electronics is to use individual molecules as the active electronic component of a real-world sturdy device
The extension of the single-molecule junction approach to a silicon substrate contributes to the level of miniaturization of electronic components and it is anticipated it will pave the way to a new class of robust single-molecule circuits
One of the solutions would be a contact between the top-metal electrode and an individual molecule connected to the bottom silicon electrode, which allows for a fixed distance between the junction electrodes and would limit to one the channels across which electrons transport

Summary

Introduction

The ultimate goal in molecular electronics is to use individual molecules as the active electronic component of a real-world sturdy device. There have been great technical advances in electrical measurements at the single-molecule level[2,3,6,23] and, for instance, we and others have been able to assemble singlemolecule diodes by bridging chemically asymmetrical molecules between two metal leads[24,25,26] Such single-molecule circuits constitute the prove of concept of single-molecule circuitry, they have been limited to metal platforms leading to a restricted scope for practical applications due to their mechanical instability, their limited rectification ratios and their sensitivity to the structure of the molecule-metal contact[24]

Methods

Results

Conclusion