Growing one-dimensional metallic nanowires by dielectrophoresis

We report an electrical-field-controlled growth process for the directed bottom-up assembly of one-dimensional palladium nanowires between microfabricated electrodes. The wires, grown from an aqueous palladium salt solution by dielectrophoresis, have a thickness of only 5-10 nm and a length of up to several micrometers. The growth process depends largely on both the strength of the applied ac field and the concentration of the metal salt solution. The conditions for optimum growth are evaluated. Room-temperature current-voltage measurements show ohmic behavior and indicate electromigration effects at higher voltages. Low-temperature transport measurements reveal localization effects with a characteristic resistance minimum at 20 K. The temperature dependence below the minimum shows the wires to be one dimensional in their electron-transport properties. The investigated growth method is capable of building complex circuit patterns for future nanoelectronics.