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In this work, native GaOx is positioned between bulk gallium and degenerately doped p-type silicon (p+-Si) to form Ga/GaOx/SiOx/p+-Si junctions. These junctions show memristive behavior, exhibiting large current-voltage hysteresis. When cycled between −2.5 and 2.5 V, an abrupt insulator-metal transition is observed that is reversible when the polarity is reversed. The ON/OFF ratio between the high and low resistive states in these junctions can reach values on the order of 108 and retain the ON and OFF resistive states for up to 105 s with an endurance exceeding 100 cycles. The presence of a nanoscale layer of gallium oxide is critical to achieving reversible resistive switching by formation and dissolution of the gallium filament across the switching layer.

We describe the fabrication and electrical characterization of all-silicon electrode devices to study the electronic properties of thin films of silicon nanocrystals (SiNCs). Planar, highly doped Si electrodes with contact separation of 200 nm were fabricated from silicon-on-insulator substrates, by combination of electron beam lithography and reactive ion etching. The gaps between the electrodes of height 110 nm were filled with thin-films of hexyl functionalized SiNCs (diameter 3 nm) from colloidal dispersions, via a pressure-transducing PDMS (polydimethylsiloxane) membrane. This novel approach allowed the formation of homogeneous SiNC films with precise control of their thickness in the range of 15-90 nm, practically without any voids or cracks. The measured conductance of the highly resistive SiNC films at high bias voltages up to 60 V scaled approximately linearly with gap width (5-50 mm) and gap filling height, with little device-to-device variance. We attribute the observed, pronounced hysteretic current-voltage (I-V) characteristics to space-charge-limited current transport, which-after about twenty cycles-eventually blocks the current almost completely. We propose our all-silicon device scheme and gap filling methodology as a platform to investigate charge transport in novel hybrid materials at the nanoscale, in particular in the high resistivity regime.

Direct printing of nanogap-separated metallic contact pairs is described that enables novel nanoelectronic device architectures. Nanotransfer printing (nTP) stamps are grown by molecular beam epitaxy involving layered III-V semiconductors that are selectively etched. Finished stamps comprise both the nanoscale surface trench that becomes the nanogap on printing and a microscale, predetermined geometry that affords the simultaneous integration of contact pads for external electrical testing. This nTP technique is well suited for top-contacting sensitive thin films for electrical characterization; a typical electrode configuration is illustrated by transfer-printed 13 nm thin metal films that are separated by an electrically insulating gap of ca. 30 nm.

The directed assembly of ordered arrays of cubic silver nanoparticles featuring distinct electrical threshold‐switching characteristics is reported. Threshold selectors are key elements for nonvolatile resistive random‐access‐memory architectures, as they suppress sneak path currents in crosspoint arrays. Nanocubes are site‐selectively immobilized on a TiO2‐coated silicon surface via a complementary molecular surface functionalization of nanoparticles and substrate based on a Cu(I)‐catalyzed alkyne‐azide cycloaddition without any physical template. Electrical characterization of individual silver nanocubes by conductive‐probe atomic force microscopy reveals pronounced and reproducible threshold‐switching behavior, featuring ultralow OFF currents below 1 pA, steep turn‐on slopes of

Fast Computation of Dense and Reliable Depth Maps from Stereo Images

The magnetoresistance of a two-dimensional electron system, subjected to a one- dimensional lateral potential modulation is studied for various potential amplitudes. The interplay between Landau level splitting and modulation broadening is shown to generate a transition from even to odd filling factors for the Shubnikov�de Haas resistance minima. The effect provides a tool to determine the potential amplitude. Calculations within a one-particle model agree with this evidence of the van Hove� like structure of the Landau bands.

A periodic array of cylindrical voids, embedded in a thin film of n-doped GaAs, displays a pronounced anisotropy of the classical magnetoresistance. For a geometry where the magnetic field lies in the plane of the film, we observe a characteristic dependence on the angle between current and magnetic field. This experimental finding provides a first verification of a recently predicted effect and agrees well with theoretical calculations. The observed anisotropy is due to interactions among current distortions by neighboring voids.