Self-formed nanogap junctions for electronic detection and characterization of molecules and quantum dots

Abstract

Fabrication of self-forming nanojunction devices is demonstrated using positioning of nanofloret-like building blocks that serve as self-assembled electrodes. A main feature of the device is a self-formed nanogap bridging between the nanofloret (NF) hybrid nanostructures (HNS) and a macroscopic counter-electrode. When nanostructures are introduced to the device they provide facile bridging across the nanostructure. This strategy is used to demonstrate electronic measurements across molecules and nanoparticles. Connecting the NF nanojunction to the micro-, and macro-scales is achieved by applying standard, robust, optical lithography. In addition, the devices are operable at ambient conditions and in solvent environments, where introducing molecules to the device results in a prominent change in the conductance characteristics. Furthermore, introduction of quantum dots results in the mapping of their band structure at ambient conditions. Our results provide a proof-of-concept of large scale self-forming nanogap device platform realized using simple fabrication tools. Such a technology can be used for molecular detectors, as a potential building block for molecular electronics, or as a platform for fundamental research.