Stable Synapse‐Like Memory Switching in N‐Heterocyclic Carbene Monolayers
Abstract
ABSTRACT We report a robust redox‐active N‐heterocyclic carbene (NHC) monolayer that exhibits synapse‐like behavior driven by proton‐coupled electron transfer (PCET). Our quinone‐functionalized NHC (Rex–NHC) forms densely packed, upright self‐assembled monolayers (SAMs) on Au, confirmed by cyclic voltammetry, x‐ ray photoelectron spectroscopy, sum‐frequency generation spectroscopy, and infrared reflection absorption spectroscopy. Molecular junctions built as Au–Rex–NHC//Ga 2 O 3 /EGaIn operate over ± 2 V and can withstand electric fields up to 3.3 GV/m. Bias‐induced PCET toggles between quinone (off) and hydroquinone (on) states, yielding reversible hysteresis with on/off ratios up to 1.9 × 10 2 . The devices exhibit spike‐timing and spike‐rate‐dependent plasticity, demonstrating for the first time molecular‐level neuromorphic behavior using NHCs as anchoring groups.
Article Details
Authors (12)
Ankita Das
Universität Münster
Alessandro Borrini
Hybrid Materials for Opto‐Electronics Group Department of Molecules and Materials MESA+ Institute for Nanotechnology Molecules Center and Center for Brain‐Inspired Nano Systems Faculty of Science and Technology University of Twente Enschede The Netherlands
Christian Gutheil
Organisch‐Chemisches Institut Münster Germany
Björn Braunschweig
Institut für Physikalische Chemie, Universität Münster, Corrensstrasse 28/30, 48149 Münster, Germany
Billura Shakhayeva
Institute of Physical Chemistry University of Münster Münster Germany
Georgios Katsoukis
Catalytic Processes & Materials Group Department of Chemical Engineering Faculty of Science and Technology University of Twente Enschede The Netherlands
Ab F. Nieuwenhuis
Hybrid Materials for Opto‐Electronics Group Department of Molecules and Materials MESA+ Institute for Nanotechnology Molecules Center and Center for Brain‐Inspired Nano Systems Faculty of Science and Technology University of Twente Enschede The Netherlands
Raka Ahmed
Department of Chemistry and Nano-Science Center, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark
Susanne Leitherer
Department of Chemistry and Nano-Science Center, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen Ø, Denmark
Gemma C. Solomon
Department of Chemistry and Nano-Science Center, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark
Frank Glorius
Organisch-Chemisches Institut, Universität Münster
Christian A. Nijhuis
Department of Molecules and Materials MESA+ Institute for Nanotechnology Molecules Center and Center for Brain‐Inspired Nano Systems Faculty of Science and Technology University of Twente Enschede AE the Netherlands