J. Mater Chem. C. [CLIC]

Abstract

In this work diamino-porphyrin derivatives, in their free base or cobalt complex forms, have been used to construct SMJs. Porphyrin oligomers were covalently bonded to a bottom electrode by diazonium cation electroreduction and a STM tip was used to complete the junction. Conductance versus time (G(t)) measurements reveal stable SMJs with lifetimes as long as 70 s, attributable to the diazonium bonding procedure and the amino anchoring groups. SMJ conductance was studied statistically by three methods: the STM-bj Ghisto(d) histograms, STM Gtime(t) and voltage-dependent Gvolt(V) heat maps. Conductance and attenuation factors (β) for Co or free-base porphyrin SMJs, compared by the three methods, are fully consistent, length-dependent and show a strong molecular signature. Trends in the variation of the attenuation factors versus voltage indicate a voltage-driven β decrease for both types of SMJ.

Reference

Reliable I/V Characteristics and long lifetime of Porphyrin-Based Single-Molecule Junctions

Xinlei Yao, Maxime Vonesch, Lihao Guan, Jennifer Wytko, Jean Weiss, Xiaonan Sun, and Jean-Christophe Lacroix

J. Mater Chem. C., 2024, DOI: 10.1039/D3TC04142E

Contacts

Jean Weiss & Jennifer Wytko, team CLIC, Institut de Chimie de Strasbourg, UMR 7177.