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Welding of nanomaterials is a promising technique for constructing nanodevices with robust mechanical properties. To date, fabrication of these devices is limited because of difficulties in restricting damage to the nanomaterials during the welding process. In this work, by utilizing very low fluence (∼900 μJ cm(-2)) femtosecond (fs) laser irradiation, we have produced a metallic interconnection between two adjacent silver (Ag) submicron/nanoparticles which were fixed on a silicon (Si) wafer after fs laser deposition. No additional filler material was used, and the connected particles remain almost damage free. Observation of the morphology before and after joining and finite difference time domain simulations indicate that the interconnection can be attributed to plasmonic excitation in the Ag submicron/nanoparticles. Concentration of energy between the particles leads to local ablation followed by re-deposition of the ablated material to form a bridging link that joins the two particles. This welding technique shows potential applications in the fabrication of nanodevices.

In this work, we show that well-ordered structures of silver nanoparticles on nanowire substrates can be produced by irradiation with femtosecond (fs) laser pulses at fluences ranging from 10.3 to 15.9  mJ/cm² if the direction of polarization is parallel to the long axis of the nanowire. Experimental results show that a uniformly spaced distribution of nanoparticles is more readily produced on nanowires with lengths L≤2λ, where λ=800  nm is the laser wavelength. The distribution of nanoparticles is found to become less well organized as L≥2λ. Finite element method simulations, combined with experimental observations, indicate that nanoparticles are initially distributed in response to the electric field along the clean Ag nanowire arising from optical excitation. This electric field is responsible for the attraction of nanoparticles to certain locations on the nanowire. We show how a fs-laser-driven assembly of nanoparticles on nanowires can be used in the development of a nanoscale optical logic processor. This method of creating periodic arrays of metallic nanoparticles on nanowire substrates then has many possible applications in electro-optics.

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We report a single step technique of synthesizing particle-agglomerated, amorphous 3-D nanostructures of Al and Si oxides on powder-fused aluminosilicate ceramic plates and a simple novel method of wafer-foil ablation to fabricate crystalline nanostructures of Al and Si oxides at ambient conditions. We also propose a particle size prediction mechanism to regulate the size of vapor-condensed agglomerated nanoparticles in these structures. Size characterization studies performed on the agglomerated nanoparticles of fabricated 3-D structures showed that the size distributions vary with the fluence-to-threshold ratio. The variation in laser parameters leads to varying plume temperature, pressure, amount of supersaturation, nucleation rate, and the growth rate of particles in the plume. The novel wafer-foil ablation technique could promote the possibilities of fabricating oxide nanostructures with varying Al/Si ratio, and the crystallinity of these structures enhances possible applications. The fabricated nanostructures of Al and Si oxides could have great potentials to be used in the fabrication of low power-consuming complementary metal-oxide-semiconductor circuits and in Mn catalysts to enhance the efficiency of oxidation on ethylbenzene to acetophenone in the super-critical carbon dioxide.