Self-assembled metal quantum dots

Long-range order of uniform in size and regular in shape 2D arrays of Au@TOABDT nanoparticles (4.9 nm) were formed by a displacement reaction of the outer-shells from tetraoctylammonium bromide (TOAB) to dodecanethiol (DT) molecules at room temperature. The displacement reaction has utilized both superior size and shape control of Au@TOAB nanoparticles and uniform dispersion capability of Au@DT nanoparticles to achieve an extraordinarily large in extent (3 mu m x 3 mu m) regular nanoparticle lattice structure. Self-assembled NiSi quantum dot arrays have been grown on relaxed epitaxial Si0.7Ge0.3 on (001)Si. The formation of the one-dimensional ordered structure is attributed to the nucleation of NiSi nanodots on the surface undulations induced by step bunching on the surface of SiGe film owing to the miscut of the wafers from normal to the (001)Si direction. The two-dimensional, pseudo-hexagonal structure was achieved under the influence of repulsive stress between nanodots.