No abstract available

[en] The deposition behaviour of an individual nanofibre on planar and patterned silicon substrates is studied using near-field electrospinning (NFES). A high-speed camera was utilized to investigate the formation and motion process of a liquid jet. Thanks to the shorter distance from the spinneret to the collector, bending instability and splitting of the charged jet in electrospinning were overcome. In NFES, a straight-line jet between the spinneret and the collector can be utilized to direct-write an orderly nanofibre. Perturbation stemming from residual charges on the collector caused the oscillation of the charged jet, and the deposition of the non-woven nanofibre on the planar substrate. With increasing collector speed, the impact of residual charges was weakened by the strong drag force from the collector and a straight-line nanofibre could be obtained. In addition, the nanofibre can be direct-written in a special pattern by controlling the motion track of the collector. Therefore, it can be concluded that a micro-strip pattern was a good guidance for nanofibre deposition, and the nanofibre deposition track followed well along the top surface of the micro-strip pattern. The position-controlled deposition of a single nanofibre provides a new aspect for applications of electrospinning.

[en] We show that physisorbed octadecylphosphonic acid (OPA) self-assembled monolayer (SAM) molecules on a Si substrate can be removed by a biased conductive probe tip. Our experimental results suggest that the OPA headgroups are negatively charged and adsorbed on the Si substrate through weak electric charge interaction, allowing one to selectively remove these molecules from their SAMs with an electric field

[en] A modular BioMEMS platform for tissue engineering is presented. The smart combination of silicon, glass and polymers offers microenvironments with properties applicable to cultivation, observation and manipulation of cells. The implementation of the so-called 'black silicon' as a nanostructured surface allows easy mounting and assembly with standard polymer tubing and connectors only needing an extremely small additional volume as well as the smart integration of polymer scaffold structures. Parallelization of the modular structures enables high throughput screenings and observations. Complex biomedical experiments for tissue engineering as well as water analytics can be established by cascading several modules

[en] The effects of premature edge breakdown (PEB) and available PEB prevention (PEBP) techniques in silicon avalanche photodiode fabrication using the standard complementary metal–oxide–semiconductor (CMOS) process are scrutinized in this paper. Impact of device simulation and its induced impacts on fabrication are addressed based on our design, simulation and fabrication experiences. Three most common PEBP techniques are implemented followed by a systematic study aimed at miniaturization, while optimizing the overall performance. The p-well-, p-sub- and n-well-based PEBP techniques are evaluated and compared based on simulation and fabrication results using the standard CMOS process. The results demonstrate that the n-well guard ring offers the most efficient PEBP technique. This technique offers a high-gain (∼800), low-noise dark current rate (DCR = 40 Hz), high detection efficiency (70%) avalanche photodiode with a higher functionality probability. (paper)

[en] Balanced boron (B) application is well-known to enhance the cotton production; however, the narrow range between B-deficiency and toxicity levels makes it difficult to manage. Cotton genotypes extensively differ in their response to B requirements. The adequate dose of B for one genotype may be insufficient or even toxic to other genotype. The effects of boron (B) on seed cotton yield and its various yield associated traits were studied on 10 cotton genotypes of Pakistan. The pot studies were undertaken to categorize cotton genotypes using B-deficient (control) and B-adequate (2.0 kg B ha-1) levels arranged in CRD with four repeats. The results indicated that the seed cotton yield, yield attributes and B-uptake of genotypes were comparatively decreased in B-deficient stressed treatment. Genotype NIA-Ufaq exhibited wide range of adaptation and ranked as efficient-responsive, as it produced higher seed cotton yield under both B-regimes. SAU-2 and CIM-506 were highly-efficient and remaining all genotypes were medium-efficient. Genotype Sindh-1 produced low seed cotton yield under B deficient condition and ranked as low-efficient. B-efficient cotton genotypes can be grown in B deficient soils without B application. (author)

[en] This paper presents a novel poly (PC) and active (RX) corner rounding modeling approach to SPICE simulations. A set of specially designed structures was used for measurement data collection. PC and RX corner rounding equations have been derived based on an assumption that the corner rounding area is a fragment of a circle. The equations were modified to reflect the gouging effect of physical silicon wafers. The modified general equations were implemented in the SPICE model to enable the model to describe the corner rounding effect. The good fittings between the SPICE model simulation results and the silicon data demonstrated in this paper proved that the designed corner rounding model is practical and accurate. (semiconductor devices)

[en] Short communications

[en] Calculations of a localized state density (DOS) are carried out in the framework of a well-known variant of the Anderson model, i.e., for the three-dimensional single-band Hamiltonian with diagonal disorder. Results of the calculations give three regions of the energies below the virtual crystal band edge E_G^vc characterized by different behavior of the DOS. (I) The band-edge (BE) region is placed in the vicinity of E_G^vc. Here the DOS on a linear scale is approximately a linear function of the localization energy. (II) At lower energies the Urbach law governs the DOS behavior. (III) At lower energies the DOS exhibits Lifshitz singularity dependence. Here the DOS has a very small value and rare deep centers (DC) can appear in the spectrum. The problem of the DC-band inhomogeneous broadening is also considered. Estimations of the number of localized states and of the mobility-edge position are presented. The data on single-electron-DOS energy dependence of α-Si:H are used to compare qualitatively the calculated DOS with the experiment results. Good agreement is reached both in DOS behavior and in the mobility-edge location. An aspect in the approach to the problem is an additional restriction of the trial-function class minimizing the one-instanton action. The additional restriction was obtained from the analysis of the localized state problem for the concrete realizations of the disordered system under consideration. A strong-scattering problem in the limit of small concentration of scatterers is studied, as well as the case of the three-component system consisting of a binary solution of weak scatterers with a third component comprising rare deep centers. In all of the cases considered the general expressions for the DOS including prefactors are found, as well as their approximate forms

[en] The temperature dependence of the band gap of hydrogen-passivated Si nanocrystals of radius R=0.7 and 1.1 nm has been calculated from first principles using constant-temperature molecular-dynamics simulations. The band-gap change with temperature ΔE_g(R,T)=E_g(R,T)?E_g(R,0) is obtained by averaging over the configurations sampled during the molecular-dynamics simulation. We find that ΔE_g(R,T) depends strongly on the nanocrystal size. At room temperature, the calculated ΔE_g(R,T) is approximately -150 meV for R=1.1 nm nanocrystals, and -210 meV for R=0.7 nm nanocrystals, significantly larger in magnitude than in the case of bulk Si. We also find that in Si nanocrystals the band-gap deformation potential is positive, but smaller than in bulk Si