Selective deposition of gold nanoclusters on silicon by a Galvanic displacement process

Gold nanoclusters are deposited selectively on silicon substrates by galvanic displacement from reversed micelle microemulsions. The water-in-oil system investigated comprises an organic phase (n-heptane), a surfactant (AOT), and an aqueous solution of hydrofluoric acid and metallic ions. X-ray diffraction and scanning electron microscopy are employed to investigate the correlation between the nominal size of the reversed micelles and the size of the metal clusters formed on the silicon substrate. The measured gold cluster radius is in good quantitative agreement with nominal micelle radius over a wide range of cluster size and deposition time.