Thin films of Au, Ag and Ag-Au alloy nanocrystals extending to areas of several square centimetres are obtained by deposition at the interface of water and toluene. Toluene containing chlorotris(triphenylphosphine)silver(I) and/or chlorotriphenylphosphine gold (I) is reacted with aqueous tetrakishhydroxymethlyphosphonium chloride to obtain nanocrystalline films adhered to the interfacial region. Alloying was induced by varying the composition of the toluene layer. The composition change results in regular and reproducible variation in the transport characteristics of the films, with the initially metallic deposits turning non-metallic with increased Au content. The
films at the interface were transferred to different substrates and characterized using Atomic force microscopy, UV-visible spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, Scanning and Transmission Electron microscopy.