Berkeley develops novel nanowires thinner and faster
A group led by Tyler S. Matthews at Lawrence Berkeley National Labs has published new research characterizing the unique properties of specific eutectic alloys, and their enormous potential. A eutectic alloy is a mixture of elements that melts at temperatures far lower than either of the pure components alone. “Gold-silicon eutectic liquid can safely solder chip layers together or form microscopic conducting wires, by flowing into channels in the substrate without burning up the surroundings,” says Berkeley Lab’s Junqiao Wu. An 81:19 ratio of gold to silicon melts at 363Ë Celsius, while pure versions of these elements melt at 1064°C, and 1414°C respectively. As a result, micro droplets of gold can form beads of eutectic liquid that can then be used to continually catalyze the deposition of silicon, and 'grow' silicon nanowires. Furthermore, the reaction rates are driven by the thickness of the gold, and measured 20 times faster when thickness of the gold was reduced from 300 to 20 nanometers. Wu believes the discovery may provide “new routes for the engineering and processing of nanoscale materials.”