Application of ionic liquids in single-molecule junctions: Recent advances and prospects

Single-molecule junctions, integrating individual molecules as active components between electrodes, serve as fundamental building blocks for advanced electronic and sensing technologies. The application of ionic liquids in single-molecule junctions represents a cutting-edge and rapidly evolving field of research at the intersection of nanoscience, materials chemistry, and electronics. This review explores recent advances where ionic liquids function as electrolytes, dielectric layers, and structural elements within single-molecule junctions, reshaping charge transport, redox reactions, and molecular behaviors in these nanoscale systems. We comprehensively dissect fundamental concepts, techniques, and modulation mechanisms, elucidating the roles of ionic liquids as gates, electrochemical controllers, and interface components in single-molecule junctions. Encompassing applications from functional device construction to unraveling intricate chemical reactions, this review maps the diverse applications of ionic liquids in single-molecule junctions. Moreover, we propose critical future research topics in this field, including catalysis involving ionic liquids at the single-molecule level, functionalizing single-molecule devices using ionic liquids, and probing the structure and interactions of ionic liquids. These endeavors aim to drive technological breakthroughs in nanotechnology, energy, and quantum research.