Thursday, April 17, 2008

US Patent 7358524 - Electrolyte doping of nanowire junctions

Most semiconductor devices require doping in order to create diodes, transistors and other active electronic components. Usually such doping includes both n-type doping, which adds material to the semiconductor to create an excess of electrons usable for charge transport, and p-type doping, which adds material to the semiconductor to create a deficit of electrons so that electron "holes" are usable for charge transport.

However, for nanowires performing both p and n type doping can be problematic. This patent from Samsung teaches an interesting solution in which aligned nanowires are formed to connect two electrodes and an electrolyte is filled between the spaces. Application of a voltage dissociates the electrolyte into anions (negative charged ions) and cations (positively charged ions) so as to form pn junction nanowires. Claim 1 reads:

1. A nanowire device comprising: a substrate; a first electrode layer formed on the substrate; a second electrode layer facing to the first electrode layer; a plurality of nanowires interposed at a predetermined interval between the first electrode layer and the second electrode layer to connect the same; and an electrolyte containing an electrolytic salt filling spaces between the nanowires.