For nanoscale electrical characterization and device fabrication, it is often desirable to fabricate planar metal electrodes separated by large aspect ratio gaps with interelectrode distances well below 100nm. We demonstrate a self-aligned process accomplish this goal using thin Cr film as sacrificial etch layer. The resulting can be small 10nm have ratios exceeding 1000, excellent isolation. Such Ti∕Au are demonstrated on Si substrates used examine voltage-driven transition in magnetite...

The Z <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1/2</sub> defect, a deep acceptor level in high purity semi-insulating (HPSI) 4H-SiC, plays an important role optoelectronic properties, particularly below bandgap photon absorption and carrier recombination processes. Its concentration is highly dependent upon temperature annealing. To study the effect of annealing on properties HPSI vertical-type photoconductive semiconductor switches were...

Highly luminescent graphene oxide (GO)–phosphor hybrid thin films with a maximum quantum yield of 9.6% were synthesized via simple chemical method. An intense luminescence emission peak at 537 nm and broad 400 observed from the GO–phosphor films. The emissions was found to be 9.6%, which is 48 times higher than that pristine GO hybrids prepared spin-coating subsequent postannealing films, resulting in scrolling sheets. nanoscrolls exhibited length ∼2 μm nanoscale interior cavities....

Gold nanoshells (~160 nm in diameter) were encapsulated within a shell of temperature-responsive poly(N-isopropylacrylamide-co-acrylic acid) (P(NIPAM-co-AA)) using surface-bound rationally-designed free radical initiator water for the development photothermally-induced drug-delivery system. The morphologies resultant hydrogel-coated analyzed by scanning electron microscopy (SEM), while behavior nanoparticles was characterized dynamic light scattering (DLS). diameter P(NIPAM-co-AA) decreased...

We study hot electron transport in short-channel suspended multilayer graphene devices created by a distinct experimental approach. For with semitransparent contact barriers, dip of differential conductance $(dI/dV)$ has been observed at source-drain bias ${V}_{d}=0$, along anomalies higher ${V}_{d}$ likely induced optical-phonon scattering. low-contact only the $dI/dV$ ${V}_{d}=0$ is observed, and we find well-fit logarithmic dependence on both temperature $T$. The explained effect $T$...

High purity semi-insulating (HPSI) 4H-silicon carbide (SiC) was used to fabricate lateral and vertical photoconductive semiconductor switches (PCSSs). The PCSSs were illuminated from the frontside (fPCSS) or backside (bPCSS). side-illuminated PCSS (vPCSS) designed increase light-matter interaction volume. A 532-nm pulsed laser with adjustable energy utilized excite PCSSs. turn-on time found be highly dependent on optical illumination energy, full-width at half-maximum of output waveforms...

A novel fabrication technique that can be used for making a series of suspended graphene field-effect transistors on Si-substrate is discussed. The electrical properties channel significantly degraded by defects and chemical residues between substrate. To minimize degradation, method physically suspending from the substrate has been considered while maintaining its structural integrity. address this problem, we employed sandwich to fabricate GFET, realizing 76% device yield higher than those...

A transfer of a VA-SWNT film onto conductive surface has been achieved using novel "flip-over" technique. The top was covered by entangled bundles in an as-grown sample. When flipped over, optically flat consisting the tips very well aligned, clean from bottom are exposed while is contacted to substrate. Thus, we expect this technique provide us with means prepare carbon nanotube electrodes for device applications such as super capacitors, thermo-electric devices, fuel cells, and field...

Quantum corrections to the conductivity allow experimental assessment of electronic coherence in metals. We consider whether independent measurements different are quantitatively consistent, particularly systems with spin-orbit or magnetic impurity scattering. report weak localization and time-dependent universal conductance fluctuation data quasi-one- two-dimensional AuPd wires between 2 K 20 K. The inferred from both methods excellent quantitative agreement, implying that precisely same...

A graphene-based capacitive NO2 sensing device was developed by utilizing the quantum capacitance effect. We have used a graphene field-effect transistor (G-FET) whose geometrical is enhanced incorporating an aluminum back-gate electrode with naturally oxidized surface as insulating layer. When graphene, top-side of device, exposed to NO2, and, thus, measured changed in accordance concentrations ranging from 1-100 parts per million (ppm). The operational principle proposed system also...

Quantum transport phenomena allow experimental assessment of the phase coherence information in metals. We report quantitative comparisons lengths inferred from weak localization magnetoresistance measurements and time-dependent universal conductance fluctuation data. describe these two their analysis. Strong agreement is observed both quasi-2D quasi-1D AuPd samples, a metal known to have high spin-orbit scattering. However, {\it disagreement} seen Ag wires below 10 K, material with...

Photoconductive semiconductor switch (PCSS) allowing side illumination was fabricated on high purity semi-insulating (HPSI) 4H-SiC. A 532-nm pulsed laser with variable optical energy used to trigger the PCSS. The performance of PCSS characterized under two different load conditions, 50-Ω and 0.05-Ω, a current viewing resistor (CVR). exhibited significantly output characteristics for loads. equivalent resistance load, which calculated from voltage current, inversely proportional energy, but...

Quantum coherence of electrons in ferromagnetic metals is difficult to assess experimentally. We report measurements time-dependent universal conductance fluctuations metal $({\mathrm{Ni}}_{0.8}{\mathrm{Fe}}_{0.2})$ nanostructures as a function temperature and magnetic field strength orientation. find that the Cooperon contribution this quantum correction suppressed, domain wall motion can be source coherence-enhanced fluctuations. The are more strongly dependent than those normal metals,...

Quantum corrections to the electrical conduction of magnetic semiconductors are comparatively unexplored. The authors report measurements time-dependent universal conductance fluctuations (TDUCFs) and field dependent (MFUCFs) in micron-scale structures fabricated from two different In1−xMnxAs thin films. TDUCF MFUCF increasing magnitude with decreasing temperature observed. At 4K below, TDUCFs suppressed at finite fields independent orientation.

We report a tunable magnetoresistance (MR) behavior in suspended graphitic multilayers through point defect engineering by ion implantation. find that implantation drastically changes the MR behavior: linear positive pure transforms into negative after introducing significant short-range disorders (implanted boron or carbon atoms), consistent with recent non-Markovian transport theory. Our experiments suggest important role of process intriguing for systems, and open new window understanding...

A novel template of single-crystalline-like germanium has been developed on low-cost, flexible metal substrates for growth high efficiency photovoltaics. The technology is enabled by the process ion beam assisted deposition (IBAD) MgO followed epitaxial a series oxide films. IBAD as well all processes up to Ge layer was conducted reel-to-reel continuous processing. degree biaxial texture achieved in film when it grown epitaxially intermediate fluorite films such CeO <sub...