We report the first successful application of corona charging noncontact C-V and I-V metrology to interface and dielectric characterization of high-k/III-V structures. The metrology, which has been commonly used in Si IC manufacturing, uses incremental corona charge dosing, ΔQC, on the dielectric surface, and the measurement of surface voltage response, ΔVS, using a Kelvin-probe. Its application to In0.53Ga0.47As with a high-k stack required modifications related to the effects of dielectric trap induced voltage transients. The developed Corona Charge-Kelvin Probe Metrology adopted strictly differential measurements using ΔQC and ΔV, and corresponding differential capacitance rather than measurements based on total global charge, Q, and voltage, V, values.

Electrical characterization data including interface trap density, electrical oxide thickness, and dielectric leakage are presented for a sample containing an In0.53 Ga0.47 As channel overlaid with a bilayer (2nm Al2O3/5nm HfO2) dielectric stack that is considered to be very promising for application in performance NFETs with high-mobility channels.

A solid-state nanopore was integrated into an optofluidic sensor chip, liquid-core anti-resonant reflecting optical waveguide (ARROW). The solid-state nanopore worked as a smart gate, which simultaneously provided characteristic electrical signals and controlled the entry of single nanoparticles into the liquid-core channel. The subsequent fluorescence detection further identified the nanoparticles by providing optical signals within a specific wavelength range. In this work, correlated electrical and optical detection of single nanoparticles, H1N1 viruses, and λ-DNA molecules was demonstrated. Different types of particles in a mixture were successfully discriminated. Moreover, the flow velocity in the liquid-core channel was extracted with the help of combined analysis of electrical and optical signals. Enhanced electrical sensitivity using a solid-state nanopore with a thin limiting aperture sculpted by SiO2 deposition was also shown.

Quantum dots (QDs) and nanoparticles (NPs) with tunable optoelectronic properties are actively researched for photovoltaic (PV) fabrication and will enter mainstream manufacturing in the future. The toxicology, health and safety of these new materials are not fully explored yet. In this work, the toxicological potencies of nanomaterials in PV fabrication, study needs, and metrology requirements are presented. Practical processes involving QDs and NPs developed for PV fabrication are presented. Experimental evidence on the presence of airborne nanomaterials in the condensates collected from process environment underlines the need for in-depth toxicity studies before these technologies scale up to the PV manufacturing stage. Required technical capabilities for the metrology tools to accurately detect, identify, and quantify QDs and NPs in PV manufacturing requirements are also presented based on the potential range of nanomaterials to be used in PV technology. These studies are key to develop safe techniques and processing environments, and to establish safety guidelines for PV fabrication with nanomaterials.

Electrokinetic based micro- and nanofluidic technologies provide revolutionary opportunities to separate, identify and analyze biomolecular species. Key to fully harnessing the power of such systems is the development of a robust method for integrated electrodes as well as a thorough understanding of the influence of the electrokinetic surface properties with and without different surface modifications. In this work, we demonstrate a surface micromachined fabrication approach for integrated addressable metal electrodes within centimeter-long nanofluidic channels using a low-temperature, xenon diflouride dry-release method for novel biosensing applications, as well as recent results from a joint theoretical and experimental study of electrokinetic surface properties in nano- and microfluidic channels fabricated with fused silica. The main contribution of this fabrication process involves the addition of addressable electrodes to a novel dry-release channel fabrication method, produced at <300°C, to be used in nanofluidic electronic sensing of biomolecules. Finally, we also show a novel method with which to coat our channels with silane based chemistries. Certain modifications are observed to show improved resistance to non-specific adhesion of both small molecules and proteins, indicating their further use as compatible surfaces in micro- and nanofluidic applications.

We report on a new class of materials for laser printer toner applications. These materials were prepared from methacrysilane-in-water emulsions stabilized with colloidal silica particles. In this elegant system, the colloidal silica particles reside at the water/oil interface helping to emulsify the oil droplet, self-organizing into a raspberry-like morphology. The emulsion formation is followed by free-radical polymerization, hydrophobic treatment, and drying steps. This one pot synthesis in water affords a hydrophobic material with a particle size in the range of 80 to 300 nm. The particle size could be fine-tuned by changing the oil-to-silica mass ratio or by using colloidal silica particles of different sizes. Results of material characterization by solid-state NMR, electron microscopy, and particle size measurements methods will be presented. Examples of possible extensions of the synthesis towards materials with methacrylsilane partially substituted with other methacrylates will be provided. Application of the new material in toners will be described as will the comparison of its performance with the incumbent material - hydrophobic colloidal silica.

Asphalt concrete is the most common material for highway and motorway construction. The quality of asphalt is determined, to a large extent, by properties of asphalt binder. Fillers, which are mineral powders from carbonate rocks and aggregates fines, such as limestone and dolomite, are often used in the composition of bitumen mastics affecting the performance of asphalt.

This article explores the feasibility of using the fines of aluminosilicate sedimentary rocks as fillers. These materials are composed of clay minerals, which change their properties upon the contact with water. Normally, the use of such fillers is restricted because of poor water resistance and swelling of asphalt concrete. In order to improve the performance of these fillers, the thermal modification at moderate temperatures of 500–600 °C has been proposed. Such treatment provides sufficient structural stability of obtained materials and results in the reduction of water absorption of asphalt, improved water resistance (up to 2.5 times) and also, in reduced swelling (up to 9 times).

It has been demonstrated that improvement in the filler performance can be achieved by a heat treatment. Such treatment induces changes in the mineral composition and converts the structure of clay minerals into the frame structure of zeolite, as confirmed by X-ray diffraction and infrared spectroscopy. Due to thermal treatment, there is a change in the acid-base properties of the surface of the filler, which is reflected in the profiles of the main adsorption centers. As a result, due to chemisorption, the modified aluminosilicate fillers are able to interact with bitumen. The application of new filler materials in asphalt concrete enables to enhance the performance.

In this paper, the effect of shock compression on the synthesis of a Bi-based oxide superconductor was investigated. Bi1.85-Pb0.35-Sr1.90-Ca2.05-Cu3.05-Ox calcined powder was shock-compacted around 20 GPa and 30 GPa, and divided specimens were annealed at 845 °C for 1, 6 and 48 hours. The specimens were evaluated by x-ray diffraction and scanning electron microscope.

Light-emitting diodes (LEDs) based on the conventional III-V compound semiconductors are known to exhibit internal quantum efficiencies (IQE) that are very close to unity. Ideally, the high IQE is expected to enable electroluminescent cooling with a cooling capacity of several Watts per cm2 of emitter area. One key requirement in enabling such cooling is the ability to fabricate high quality large area LEDs. However, detailed information on the performance of relevant large area devices and their yield is extremely scarce. In this report we present data on the yield and related large area scaling of InP/InGaAs LEDs by using current-voltage measurements performed on LED wafers fabricated at five different facilities. The samples were processed to contain square shaped mesas of sizes 0.25 mm2 and 16 mm2 operating as LEDs. While most of the smaller mesas showed relatively good electrical characteristics and low leakage current densities, some of them also exhibited very large leakage currents. In addition, in some cases the large area devices exhibited large, and even almost linearly behaving leakage currents. Such information on the scaling and unidealities of diodes fabricated using established fabrication technologies is crucial for the development of the optical cooling technologies relying on large area devices.

Contemporary methods for dispersion of carbon nanotubes in water and non-aqueous media are discussed. Main attention is paid to ultrasonic, plasma techniques and other physical techniques, as well as to the use of surfactants, functionalizing and debundling agents of distinct nature (elemental substances, metal and organic salts, mineral and organic acids, oxides, inorganic and organic peroxides, organic sulfonates, polymers, dyes, natural products, biomolecules, and coordination compounds).

As a part of the IMI-NFG’s series of low-cost experiments in glass science [1,2] we have developed a simple home-built apparatus for measuring the thermal conductivity of glassy materials, from polymers to oxide glasses, in the range of 0.1 to 1.5 W/ °C. Our apparatus is inexpensive, relatively easy to construct and accurate enough for students to use for quantitative measurements of their own glass or polymer samples. Standard materials are used to demonstrate good correlation with literature values. We also measured the thermal conductivity of a silica filled epoxy and showed a linear increase with fill fraction to 20%. This simple, low-cost method can provide students and researchers with a much broader access to this important property.

In this article, we report the synthesis of unique mesoporous Au-loaded Fe2O3nanoparticle assemblies (Au/Fe2O3-NPAs) through a surfactant-assisted aggregating assembly method. The resulting network structure, which composed of small Au nanocrystals (ca. 5 nm) finely dispersed on surface of Fe2O3 NPs (ca. 6–7 nm), possesses a 3D open-pore structure with a BET surface area of 123 m2g-1 and uniform mesopores (∼4.5 nm). Au/Fe2O3-NPAs showed high catalytic activity and chemical stability for the selective transformation of nitroaromatic compounds into the corresponding amines, using 1,1,3,3-tetramethyl disiloxane as reducing agent at ambient conditions.

With the rise of ageing population, the need to restore the function of degenerative bone greatly drives the market for bone grafts. Hydroxyapatite (HA) is chemically similar to natural bone mineral and has been widely used in bone graft applications. However, its slow osseointegration process and lack of antibacterial property could lead to implant-related infection, resulting in implant failure. Studies on ionic substitution of apatite have gained attention in recent years with greater understanding of the composition of bone mineral being a multi-substituted apatite. An integrated approach is proposed by co-substituting silver (Ag) and silicon (Si) into HA (Ag,Si-HA) to modify its surface for bi-functional properties. Incorporation of Si can enhance the biomineralization of HA and introduction of Ag can create antibacterial property. Ag,Si-HA containing 0.5 wt.% of Ag and 0.8 wt.% of Si was prepared by a wet precipitation method. A phase-pure apatite with a nanorod morphology of dimensions 60 nm in length and 10 nm in width was synthesized. Surface Ag+ ions of Ag,Si-HA were demonstrated to prevent the replication of adherent Staphylococcus aureus bacteria for up to 120 h. Biocompatibility tests revealed that human adipose-derived mesenchymal stem cells (hMSCs) proliferated well on Ag,Si-HA with culturing time. Enhanced cell attachment in turn permitted greater bone differentiation as evidenced in the increase of collagen type I and osteocalcin expressions of hMSCs cultured on Ag,Si-HA as compared to HA from day 14 onwards. Overall, co-substitution of Ag and Si could complement the benefits of each substituent by endowing HA with antibacterial property, and concurrently promoting its biological performance. Their synergistic effects can serve unmet medical needs and solve the problem of implant-related infection. This work also enhances the understanding of substituted apatite with multiple ions for bi-functional properties.

We investigate the built-in voltage in organic bulk heterojunction solar cells using electroabsorption spectroscopy based on the Stark effect, i.e. the variation of the absorption energies of a material caused by an electric field. Due to spectral contributions of permanent dipoles, a novel approach for evaluating the EA spectra is required. We use a fitting routine analyzing a broad spectral range instead of using only a single wavelength. A reliable quantitative determination of the built-in voltage is achieved.

In this work we present a theoretical study of the transport coefficients of n-type PbTe. The electronic transport coefficients are calculated using the isotropic-nearly-free-electron approximation, including the effect of band non-parabolicity on electron-phonon scattering. The lattice thermal transport coefficient is computed by employing the isotropic continuum model for the dispersion relation for acoustic as well as optical phonon branches, an isotropic anharmonic continuum model for crystal anharmonicity, and the single-mode relaxation time scheme. The role of transverse optical (TO) phonon modes in anharmonic interactions will be discussed in detail.

The relationship between nanoparticle geometry and their two dimensional assembly is investigated in order to provide insights into the three dimensional arrangement of mesocrystals. The crystal structure of the nanoparticles and their homogeneity are investigated during structure formation on the mesoscale whereby effects such as fibrillation have been observed.

LaNiO3 thin films were deposited on SrLaAlO4 (100) and SrLaAlO4 (001) single crystal substrates by a chemical solution deposition method and heat-treated in oxygen atmosphere at 700°C in tube oven. Structural, morphological, and electrical properties of the LaNiO3 thin films were characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), field emission scanning electron microscopy (FE-SEM), and electrical resistivity as temperature function (Hall measurements). The X-ray diffraction data indicated good crystallinity and a structural preferential orientation. The LaNiO3 thin films have a very flat surface and no droplet was found on their surfaces. Samples of LaNiO3 grown onto (100) and (001) oriented SrLaAlO4 single crystal substrates reveled average grain size by AFM approximately 15-30 and 20-35 nm, respectively. Transport characteristics observed were clearly dependent upon the substrate orientation which exhibited a metal-to-insulator transition. The underlying mechanism is a result of competition between the mobility edge and the Fermi energy through the occupation of electron states which in turn is controlled by the disorder level induced by different growth surfaces.

One of the major barriers to the adoption of solid oxide fuel cells (SOFCs) is the short lifetime of the fuel cell stacks. A stack consists of a number of cells in series separated by an interconnect. Due to the high temperatures necessary for SOFCs, typical commercial interconnects are ceramic. Great attention has been paid to decreasing the operating temperature of SOFCs in order to extend the life and decrease the cost of the stack. As operating temperatures decrease below 1000°C, alternative interconnect materials become viable. Stainless steel interconnects are more cost effective than ceramic interconnects but the high temperatures and the oxidizing environment of the cathode leads to the formation of a chromium oxide scale that increases the stack resistance. Chromium from the stainless steel can also enter the vapor phase and redeposit on the cathode thereby blocking the electrochemically active sites. One method to neutralize these effects is to coat the metallic interconnect in a ceramic such as La.8Sr.2MnO3 (LSM). The coating acts as a diffusion barrier both against chromium diffusing into the cathode and oxygen diffusing into the interconnect. In this study LSM has been deposited using plasma spray and tested in a dual atmosphere setup using impedance spectroscopy to analyze the performance of the coatings at various temperatures. The area specific resistance and chemical composition of the scale was examined in order to determine the affect of the LSM coating.

In this study, the formation of Ni-(GeSn)x on strained and relaxed Ge1−xSnx (0.01≤x≤ 0.03) nanowires in contact areas has been investigated. The epi-layers were grown at different temperatures (290 to 380°C) by RPCVD technique. The strain in GeSn layers tailored through carefully chosen of growth parameters and virtual substrate. The nanowires were fabricated through both I-line and dry-etching. 15 nm Ni was deposited either on the contact areas or whole length of nanowires. The wires went through rapid thermal annealing at intervals of 360 to 550°C for 30s in N2 ambient. The results show the thermal stability and amount of particular phases were strain-dependent. The formation of Ni-GeSn was eased when GeSn layers were strain-free. When the Sn content is high the epi-layers suffer from Sn segregation. The Sn-rich surface impedes remarkably the Ni diffusion. The electrical conductivity measurement of nanowires shows low resistivity and Ohmic contact are obtained for Ni-GeSn.

Hybrid organic/inorganic nanostructures are engineered to function as two terminal devices with enhanced functionality. The devices are the building blocks for designing hybrid organic/inorganic circuits in the nanoscale. In our work, we have demonstrated the sensing capabilities of polymer nanocomposite thin films for designing nanoweb devices towards detection of biomolecules. Biomolecules with surface charge such as troponin-T were detected on this device by interfacing them with the polymer/metal composites. The change in electrical properties due to modulation in charge transport at the crossbar junction was identified as the measured electrical signal for designing switch based sensors. Nanotextured surface offers strong charge carrier transport and hence enhances the strength of the detected signal. The antibodyantigen interactions at the junction effectively modulate the charge transfer kinetics and modify the junction characteristics due to the surface potential associated with the organic molecules. The net change in surface charge can be measured either as changes in the diode current in the two terminal configuration or as changes in the source- drain current in the three terminal configuration. Detection sensitivity in the order of pg/mL was targeted by measuring the voltammetric current response (in microamperes).