On-Surface Single-Molecule Identification of Mass-Selected Cyclodextrin-Supported Polyoxovanadates for Multistate Resistive-Switching Memory Applications
Fangshun Yang, Marco Moors, Duc Anh Hoang, Sebastian Schmitz, Markus Rohdenburg, Harald Knorke, Aleš Charvát, Xue‐Bin Wang, Kirill Yu. Monakhov, Jonas Warneke
Abstract
Polyoxovanadate anions immobilized on conducting substrates are promising candidates for molecule-based memory technologies. However, strong electronic interactions with the substrate and the formation of larger agglomerates remain bottlenecks on the way to their technical application. We demonstrate that ion soft-landing of mass selected cyclodextrin-functionalized hexavanadates enables deposition of these host–guest complexes as single memory units on surfaces without their quaternary ammonium countercations from solution. Cyclodextrin provides a stabilizing “shell” for the dianions. Multistate switching evidenced by the change in molecular resistance has been detected using scanning tunneling microscopy and spectroscopy and attributed to reduction of individual vanadium (+V) centers.