doi:10.1039/C4NR02933JengWimbush, Kim S.Fratila, Raluca M.Wang, DandanQi, DongchenLiang, CaoYuan, LiYakovlev, NikolaiLoh, Kian PingReinhoudt, David N.Velders, Aldrik H.Nijhuis, Christian A.Bias Induced Transition from an Ohmic to a Non-Ohmic Interface in Supramolecular Tunneling Junctions with Ga2O3/EGaIn Top ElectrodesART-2014-85951This study describes that the current rectification ratio, R = |J|(-2.0 V)/|J|(+2.0 V) for supramolecular tunneling junctions with a top-electrode of eutectic gallium indium (EGaIn) that contains a conductive thin (0.7 nm) supporting outer oxide layer (Ga2O3), increases by up to four orders of magnitude under an applied bias of >+1.0 V up to +2.5 V; these junctions did not change their electrical characteristics when biased in the voltage range of ±1.0 V. The increase in R is caused by the presence of water and ions in the supramolecular assemblies which react with the Ga2O3/EGaIn layer and increase the thickness of the Ga2O3 layer. This increase in the oxide thickness from 0.7 nm to ~2.0 nm changed the nature of the monolayer–top-electrode contact from an ohmic to a non-ohmic contact. These results unambiguously expose the experimental conditions that allow for a safe bias window of ±1.0 V (the range of biases studies of charge transport using this technique are normally conducted) to investigate molecular effects in molecular electronic junctions with Ga2O3/EGaIn top-electrodes where electrochemical reactions are not significant. Our findings also show that the interpretation of data in studies involving applied biases of >1.0 V may be complicated by electrochemical side reactions which can be recognized by changes of the electrical characteristics as a function voltage cycling or in current retention experiments.2014http://zaguan.unizar.es/record/5787610.1039/C4NR02933Jhttp://zaguan.unizar.es/record/57876oai:zaguan.unizar.es:57876NANOSCALE 6, 19 (2014), 11246-58by-nchttp://creativecommons.org/licenses/by-nc/3.0/es/info:eu-repo/semantics/openAccess