A Tunneling Nanoswitch Based on Mechanically-Tunable Molecular Junctions

We show that monolayers of molecules can be used as active, mechanically-tunable components in nanometer-scale electromechanical switches. Using molecules as controllable-length nanosprings, our nanoelectromechanical (NEM) switches overcome the typical challenges of high actuation voltages and slow switching speeds for previous NEM technologies. Our NEM switches are hierarchically assembled using a molecular spacer layer sandwiched between atomically smooth electrodes, which defines a nanometer-scale electrode gap and can be electrostatically compressed to repeatedly modulate the tunneling current. The molecular layer and the top electrode structure serve as two degrees of design freedom with which to independently tailor static and dynamic device characteristics, enabling simultaneous low turn-on voltages (sub-3 V) and short switching delays (2 ns). This molecular platform with inherent nanoscale modularity provides a versatile strategy for engineering diverse high-performance and energy-efficient electromechanical devices.