Nano Letters [CLAC]

Abstract :

Single-molecule junctions (SMJs) have been fabricated using layers generated by diazonium electroreduction. This process creates a C–Au covalent bond between the molecule and the electrode. Rigid oligomers of variable length, based on porphyrin derivatives in their free base or cobalt complex forms, have been grafted on the surface. The conductance of the oligomers has been studied by a scanning tunneling microscopy break junction (STM-bj) technique and G(t) measurements, and the lifetime of the SMJs has been investigated. The conductance histograms indicate that charge transport in the porphyrins is relatively efficient and influenced by the presence of the cobalt center. With both systems, random telegraph G(t) signals are easily recorded, showing SMJ on/off states. The SMJs then stabilize and exhibit a surprisingly long lifetime around 10 s, and attenuation plots, obtained by both G(t) and STM-bj measurements, give identical values. This work shows that highly stable SMJs can be prepared using a diazonium grafting approach.

Graphical Abstract:

 
 

 

Reference :

Xinlei Yao, Maxime Vonesch, Maïwenn Combes, Jean Weiss, Xiaonan Sun, and Jean-Christophe Lacroix

Single-Molecule Junctions with Highly Improved Stability

Nano Letters, first published July 21, 2021 -  DOI: https://doi.org/10.1021/acs.nanolett.1c01747

Contact :

Jean Weiss, équipe CLAC ( https://lclac.chimie.unistra.fr/ ) Institut de Chimie (UMR 7177).