Current state and perspectives of nanoscale molecular rectifiers

TL;DR

This paper reviews the current state, recent progress, and future prospects of nanoscale molecular rectifiers, highlighting design strategies, key parameters, and challenges towards commercialization in molecular electronics.

Contribution

It provides a comprehensive overview and critical analysis of various molecular rectification mechanisms and recent advancements, emphasizing design concepts and material platforms.

Findings

Recent rectification ratios exceeding 10^5

Multiple design strategies for molecular rectifiers

Identification of key parameters influencing rectification

Abstract

The concept of utilizing a molecule bridged between two electrodes as a stable rectifying device with the possibility of commercialization is a "holy grail" of molecular electronics. Molecular rectifiers do not only exploit the electronic function of the molecules but also offer the possibility of their direct integration into specific nano-electronic circuits. However, even after nearly three decades of extensive experimental and theoretical work, the concept of molecular rectifiers still has many unresolved aspects concerning both the fundamental understanding of the underlying phenomena and the practical realization. At the same time, recent advancements in molecular systems with rectification ratios exceeding 105 are highly promising and competitive to the existing silicon-based devices. Here, we provide an overview and critical analysis of the current state and recent progress in molecular rectification relying on the different design concepts and material platforms such as single molecules, self-assembled monolayers, molecular multilayers, heterostructures, and metal-organic frameworks and coordination polymers. The involvement of crucial parameters such as the energy of molecular orbitals, electrode-molecule coupling, and asymmetric shifting of the energy levels will be discussed. Finally, we conclude by critically addressing the challenges and prospects for progress in the field and perspectives for the commercialization of molecular rectifiers.