title: Real time and in situ control of the gap size of nanoelectrodes for molecular devices.
abstract: Molecular electronics is often limited by the lack of a simple method to fabricate nanoelectrodes with controlled gap size. This is partly attributed to the lack of a real time characterization in the fabrication. Here, we report a new method based on an electron induced deposition process operated in scanning electron microscopy that realizes in situ and real time characterization in the nanoelectrode fabrication; thus the gap size can be controlled easily and precisely. It is a clean and nondestructive process for carbon nanotube (CNT) electrodes. The mechanism is detailed. The nanoelectrodes have a pi-conjugated surface due to the deposition of sp(2)-rich amorphous carbon. As an application, DNA molecules are assembled between the CNT electrodes by pi-stacking interaction for current-voltage measurement. Our result provides a feasible route to prepare nanoelectrodes with controlled gap size, and it will be valuable for current efforts in molecular electronics and nanoelectronics.
authors.affiliation: Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, and the Graduate School, Chinese Academy of Sciences, Beijing, PR China.
authors.forename: Dacheng
authors.initials: D
authors.lastname: Wei
authors.forename: Yunqi
authors.initials: Y
authors.lastname: Liu
authors.forename: Lingchao
authors.initials: L
authors.lastname: Cao
authors.forename: Yu
authors.initials: Y
authors.lastname: Wang
authors.forename: Hongliang
authors.initials: H
authors.lastname: Zhang
authors.forename: Gui
authors.initials: G
authors.lastname: Yu
mesh_terms: D003199:Computer Systems; D004563:Electrochemistry / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design / Q000379:methods*; D019544:Equipment Failure Analysis; D008422:Materials Testing; D008839:Microelectrodes; D036103:Nanotechnology / Q000295:instrumentation* / Q000379:methods