Single-molecule conductance with nitrile and amino contacts with Ag or Cu electrodes

• DOI: 10.1016/j.electacta.2015.06.018
• Publication Date: 2015-06-06T19:07:56Z
• Authors: Dong-Fang Li; Jin-Chuan Mao; De-Li Chen; Fang Chen; Hong Ze-Wen; Xiao-Yi Zhou; Ya-Hao Wang; Xiao-Shun Zhou; Zhen-Jiang Niu; Emmanuel Maisonhaute
• Keywords: Break junction

The single-molecule conductance of 1,4-dicyanobenzene (DCB), 1,4-benzenediamine (BDA) and 4,4'-biphenyldicarbonitrile (BPDC) with Ag and/or Cu electrodes is measured by electrochemical jump-tocontactSTM-break junction. All single-molecule junctions present three sets of conductance valuesrevealing different contact geometries. We observe that the single-molecule conductance of Ag-BDA-Agjunction is larger that of Ag-DCB-Ag junction, and DCB with Ag contacts are more conductive than thatwith Cu ones. This is related to a different electronic coupling between the molecules and the electrodes.Tunneling decay constants of 1.70 and 1.68 per phenyl group were found for Ag and Cu electrodes,respectively. The present study therefore shows that nitrile and amino groups can also be used aseffective anchors for other metals than gold.