We introduce a new concept for the solution-based fabrication of conductive gold nanowires using DNA templates. To this end, we employ DNA nanomolds, inside which electroless gold deposition is initiated by site-specific attached seeds. Using programmable interfaces, individual molds self-assemble into micrometer-long mold superstructures. During subsequent internal gold deposition, the mold walls constrain the metal growth, such that highly homogeneous nanowires with 20-30 nm diameters are obtained. Wire contacting using electron-beam lithography and electrical conductance characterization at temperatures between 4.2 K and room temperature demonstrate that metallic conducting wires were produced, although for part of the wires, the conductance is limited by boundaries between gold grains. Using different mold designs, our synthesis scheme will, in the future, allow the fabrication of complex metal structures with programmable shapes.

Advances in DNA nanotechnology allow the design and fabrication of highly complex DNA structures, uisng specific programmable interactions between smaller nucleic acid building blocks. To convey this concept to the fabrication of metallic nanoparticles, an assembly platform is developed based on a few basic DNA structures that can serve as molds. Programming specific interactions between these elements allows the assembly of mold superstructures with a range of different geometries. Subsequent seeded growth of gold within the mold cavities enables the synthesis of complex metal structures including tightly DNA‐caged particles, rolling‐pin‐ and dumbbell‐shaped particles, as well as T‐shaped and loop particles with high continuity. The method further supports the formation of higher‐order assemblies of the obtained metal geometries. Based on electrical and optical characterizations, it is expected that the developed platform is a valuable tool for a self‐assembly‐based fabrication of nanoelectronic and nanooptic devices.

Effect of O 2 /Ar flow ratio and post-deposition annealing on the structural, optical and electrical characteristics of SrTiO 3 thin films deposited by RF sputtering at room temperature, Thin Solid Films (2015), SrTiO 3 (STO) thin films have been prepared by reactive rf magnetron sputtering on Si (100) and UV fused silica substrates at room temperature. The effect of oxygen flow on film characteristics was investigated at a total gas flow of 30 sccm, for various O 2 /O 2 +Ar flow rate ratios. As-deposited films were annealed at 700 °C in oxygen atmosphere for 1 h. Postdeposition annealing improved both film crystallinity and spectral transmittance. Film microstructure, along with optical and electrical properties were evaluated for both asdeposited and annealed films. Abroad photoluminescence emission was observed with in the spectral range of 2.75-3.50 eV for all STO thin films irrespective of their deposition parameters. Upon annealing, the optical band gap of the film deposited with 0% O 2 concentration slightly blue-shifted, while the other samples grown at higher oxygen partial pressure did not show any shift. Refractive indices (n) (at 550 nm) were in the range of 2.05 to 2.09, and 2.10 to 2.12 for as-deposited and annealed films, respectively. Dielectric constant values (at 100 kHz) within the range of 30-66 were obtained for film thicknesses less than 300 nm, which decreased to~30-38 after post-deposition annealing.

The use of self-assembly techniques may open new possibilities in scaling down electronic circuits to their ultimate limits. Deoxyribonucleic acid (DNA) nanotechnology has already demonstrated that it can provide valuable tools for the creation of nanostructures of arbitrary shape, therefore presenting an ideal platform for the development of nanoelectronic circuits. So far, however, the electronic properties of DNA nanostructures are mostly insulating, thus limiting the use of the nanostructures in electronic circuits. Therefore, methods have been investigated that use the DNA nanostructures as templates for the deposition of electrically conducting materials along the DNA strands. The most simple such structure is given by metallic nanowires formed by deposition of metals along the DNA nanostructures. Here, we review the fabrication and the characterization of the electronic properties of nanowires, which were created using these methods.

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Experimental and numerical investigations on time-resolved characteristics of pulsed inductively coupled O 2 /Ar plasmas

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We introduce a method based on directed molecular self-assembly to manufacture and electrically characterise C-shape gold nanowires which clearly deviate from typical linear shape due to the design of the template guiding the assembly. To this end, gold nanoparticles are arranged in the desired shape on a DNA-origami template and enhanced to form a continuous wire through electroless deposition. C-shape nanowires with a size below 150nm on a $${\hbox {SiO}_2}/\hbox {Si}$$ SiO 2 / Si substrate are contacted with gold electrodes by means of electron beam lithography. Charge transport measurements of the nanowires show hopping, thermionic and tunneling transports at different temperatures in the 4.2K to 293K range. The different transport mechanisms indicate that the C-shape nanowires consist of metallic segments which are weakly coupled along the wires.