Anomalous high capacitance in a coaxial singlenanowire capacitor

摘要

Building entire multiple-component devices on single nanowires is a promising strategy forminiaturizing electronic applications. Here we demonstrate a single nanowire capacitor witha coaxial asymmetric Cu-Cu2o-C structure, fabricated using a two-step chemical reactionand vapour deposition method. The capacitance measured from a single nanowire devicecorresponds to -140 mu F cm~(-2), exceeding previous reported values for metal–insulator–metalmicro-capacitors and is more than one order of magnitude higher than what is predicted byclassical electrostatics. Quantum mechanical calculations indicate that this unusually highcapacitance may be attributed to a negative quantum capacitance of the dielectric–metalinterface, enhanced significantly at the nanoscale.