Stenciled conducting bismuth nanowires

Stencil lithography is used here for the fabrication of bismuth nanowires using thermal evaporation. This technique provides good electrical contact resistance by having the nanowire structure and the contact pads deposited at the same time. It has also the advantage of modulating nanowires' height as a function of their width. As the evaporated material deposits on the stencil mask, the apertures shrink in size until they are fully clogged and no more material can pass through. Thus, the authors obtain variable-height (from 27 to 95 nm) nanowires in the same evaporation. Upon their morphological (scanning electron microscopy and atomic force microscopy) and electrical characterizations, the authors obtain their resistivity, which is independent of the nanowire size and is the lowest reported for physical vapor deposition of Bi nanowires (1.2×10−3 Omega cm), only an order of magnitude higher than that of bulk bismuth.