Study of electron transport in electrochemically controlled molecular switches

In this project, the properties of electrochemically and chemically controlled single-molecule switches with multiple non-interacting centers will be investigated. Electron transport through their single molecules will be inspected by scanning tunneling microscopy and atomic force microscopy break junction techniques as well as by mechanically controllable break junction technique, under electrochemical conditions. Attention will be chiefly paid to finding tunneling-to-hopping transition as determined by temperature resolved conductance measurements of molecular homologues under various conditions (electrode potential, pH, presence of ions). Newly designed tripod anchoring groups will be employed to realize firm contacts between the molecule and electrodes. Results of the experimental work will be complemented by density functional theory-based calculations. Green´s function formalism will be used to obtain transmission function of the molecular junctions and to theoretically predict the single molecule conductance value. Keywords: electron transport; single molecule conductance; electrochemistry; molecular switches; scanning tunneling microscopy; atomic force microscopy