Field-emission induced growth of nanowires

Nanowires are grown from a cold-field-emission tip in the presence of a precursor, typically an organometallic or organic compound. Electron emission from the newly grown nanowire tip continues the growth and can give rise to nanowires that are tens of microns long. Single nanowires are obtained by limiting the field-emission current to values of typically 100 nA or less. Tungsten nanowires with diameters of less than 4 nm have been grown from W(CO)(6). Other nanowires grown include cobalt, iron, and carbon. Composite wires can be fabricated by continued growth with different precursors. Nanowires have been grown on etched wire tips, carbon nanotubes and scanning probe tips. Voltages applied to electrodes on an integrated circuit die can be used to attract a nanowire towards and contact a biased electrode. By such means, it is possible to connect the end of a pointed structure, such as a carbon nanotube, to an electrode. (C) 2002 American Institute of Physics.