Voltage-Driven Conformational Switching with Distinct Raman Signature in a Single-Molecule Junction

• DOI: 10.1021/jacs.7b12818
• Publication Date: 2018-03-22T18:21:51Z
• Authors: Hai Bi; Carlos-Andres Palma; Yuxiang Gong; Peter Hasch; Mark Elbing; Marcel Mayor; Joachim Reichert; Johannes V. Barth
• Keywords: Technology; ddc:600; info:eu-repo/classification/ddc/600; 600; 02 engineering and technology; 0210 nano-technology; 01 natural sciences; 0104 chemical sciences; 3. Good health

Precisely controlling well-defined, stable single-molecule junctions represents a pillar of single-molecule electronics. Early attempts to establish computing with molecular switching arrays were partly challenged by limitations in the direct chemical characterization of metal-molecule-metal junctions. While cryogenic scanning probe studies have advanced the mechanistic understanding of current- and voltage-induced conformational switching, metal-molecule-metal conformations are still largely inferred from indirect evidence. Hence, the development of robust, chemically sensitive techniques is instrumental for advancement in the field. Here we probe the conformation of a two-state molecular switch with vibrational spectroscopy, while simultaneously operating it by means of the applied voltage. Our study emphasizes measurements of single-molecule Raman spectra in a room-temperature stable single-molecule switch presenting a signal modulation of nearly 2 orders of magnitude.