Dielectrophoretic alignment and electrical characterization of CuO nanowire-based systems

Dielectrophoresis is used to assemble nanowires between metallic electrodes to form scalable functional interconnects. The dielectrophoresis parameters are investigated for semiconductor copper oxide (CuO) nanowires that are desirable for energy conversion and storage, gas sensors and nanoelectromechanical systems. Experimental yields of multiple- and single-nanowire interconnects are explored at dielectrophoresis frequencies from 500 Hz to 500 kHz. The electrical properties of nanowire-electrode physical contact interfaces formed by dielectrophoresis, metal deposition, and dry mechanical transfer are investigated. The electrical transport mechanism in these interconnects is determined to be ohmic conductivity at small electric field, which is overtaken by an order of magnitude higher space charge limited conductivity for electric fields above 10⁵ V/m. The developed method is demonstrated as a promising route to produce nanowire interconnects towards scalable on-chip nanoelectromechanical systems.