Electrical Characterization of Bismuth Sulfide Nanowire Arrays by Conductive Atomic Force Microscopy

A new method for determining the resistivity of templated Bi2S3 nanowires by conductive atomic force (C-AFM) microscopy is described in this paper. Unlike other vertical C-AFM approaches, in our method, resistance measurements were carried out along the lengths of the nanowires. Nanowires embedded within anodic alumina membranes were exposed for contact by etching away the alumina template to form an open array of parallel nanowires. From these measurements, the contact resistance between the cold electrodes and the C-AFM probe could be determined and subtracted to give the intrinsic resistivity of the nanowires. The resistivity of the nanowires determined in such a horizontal configuration was 10-100 times lower than the resistivity determined when the same nanowires were contacted in a vertical configuration.