Commercially available antimony tin oxide (ATO) nanoparticles were dispersed in water using tetramethylammonium hydroxide (TMAH) as a dispersing agent and deposited onto glass substrates by spin coating. Films of one to five layers were made. These thin films were characterized using impedance spectroscopy and ultraviolet-visible spectroscopy to obtain their sheet resistances and optical transmittance, respectively. The films displayed sheet resistances around 105-106 kΩ/☐ and optical transmittance in the near infrared to near ultraviolet range above 95%. Films were then made using a higher concentration ATO solution and found to achieve sheet resistances on the order of 102 kΩ/☐ but had decreased transmittance as low as 65% at some wavelengths. Impedance measurements, along with optical micrographs, were taken at different locations on the films. These experiments demonstrated that films of more than one layer showed greater uniformity. Additional sets of films were also produced with varying substrate preparation and dispersion deposition parameters. Aside from dispersion concentration, high humidity during film measurement was found to be the most crucial parameter for achieving low sheet resistances.

Dielectric capacitors for energy storage are of great importance in modern electronics and electric systems. It is a challenge to realize the high energy density while maintain the low dielectric loss. We investigated an ultra high breakdown electric field of 1.1 GV/m, which is approaching the intrinsic breakdown, in aromatic polythiourea, a new dielectric material that serves a high energy density of 23 J/cm3 as well as high charge-discharge efficiency above 90%. The molecular structure and film surface morphology were also studied, it was proved a polar amorphous phase and glass state material could significantly suppress the high field conduction to several orders smaller compared with regular polymer dielectric materials, which are usually semi-crystalline and in rubber phase.

High purity bulk graphite is applicable in many capacities in the nuclear industry. The thermal conductivity of graphite has been found to vary as a function of how its morphology changes on the nanoscale, and the type and number of defects present. We compute thermal conductivities at the nanolevel using large scale classical molecular dynamics simulations and by employing the Green-Kubo method in a set of in silico experiments geared towards understanding the impact of defects in the thermal conductivity of graphite. We present the results obtained for systems with 1– 3 vacancies, and compile a summary of some of the methods applied and difficulties encountered.

An amorphous silica film has been coated on a fused silica glass and KH2PO4 [KDP] crystal by using the photo oxidization of Dimethy-siloxane silicone [DMSS] oil by using a xenon [Xe2] excimer lamp at room temperature. The DMSS oil [-O-Si[CH3]2-O-]n was spin-coated on a fused silica glass to make a thin film, and the Xe2 lamp light was vertically irradiated in the presence of oxygen. Thus, the organic oil was changed into inorganic glass. In order to investigate the photochemical reaction process, the fluorescence intensity was measured by spectrometer at actual time and the new method to form a transparent, photo-oxidized thin film efficiently has been established. The interferometer analysis was conducted to investigate the strain of the coating samples. It became clear that the no strain were caused by vitrification of the silicone oil on the fused silica galass with Xe2 lamp irradiation.

Traditional assembly line manufacturing is speculative, costly and environmentally unsustainable. It is speculative because it commits substantial resources—energy, materials, shipping, handling, stocking and displaying—without a guaranteed sale. It is costly because each of these resources—material, process, people and place—involves expense not encountered when a product is manufactured at the time of sale. It is environmentally unsustainable because, no matter how much recycling is done, not using the resources unless actually needed is always a better path. Three-dimensional printing is currently of great commercial interest as it can be employed to manufacture parts on-demand economically and without the significant cost & environmental downsides, i.e. inventory and waste, associated with traditional manufacturing processes. Herein, we describe the formulation of a novel water-based material which can be used in a traditional 3D printer extrusion process to create optically transparent glass-based objects. Such objects have a wide range of applications including, but not wholly limited to: security printing using color & coating effects, protective films and coatings, electronic codes readable by smartphones, tablets or touch screens. Additional all glass objects traditionally manufactured by the so called kiln glass method can be generated by this type of 3D printing making it interesting for the high end market of art objects.

The application of micro-fourier transform infrared (FTIR) mapping analysis to thermoelectric materials towards identification of doping inhomogeneities is described. Micro-FTIR, in conjunction with fitting, is used as analytical tool for probing carrier content gradients. The plasmon frequency ω P 2 was studied as potential effective probe for carrier inhomogeneity and consequently doping differentiation based on its dependence of the carrier concentration. The method was applied to PbTe-, PbSe- and Mg2Si- based thermoelectric materials.

We present a Scanning Probe Microscopy study of doping and sensing properties of reduced graphene oxide (rGO)-based nanosensors. rGO devices are created by dielectrophoretic assembly of rGO platelets onto interdigitated electrode arrays, which are lithographically pre-patterned on top of SiO2/Si wafers. The availability of several types of oxygen functional groups allows rGO to interact with a wide range of organic dopants, including methanol, ethanol, acetone, and ammonia. We perform sensitive Scanning Kelvin Probe Microscopy (SKPM) measurements on patterned rGO electronic circuits and show that the local electrical potential and charge distribution are significantly changed when the device is exposed to organic dopants. We also demonstrate that SKPM experiments allow us to quantify the amount of charge transferred to the sensor during chemical doping, and to spatially resolve the active sites of the sensor where the doping process takes place.

CdS:Li nanoparticles were grown by the thermolysis method using a surfactant to control the nanoparticles growth and the passivity of the dangling bonds. The effect of the Li incorporation on the optical and structural properties of the CdS nanoparticles was studied by means of the optical transmission, photoluminescence, X-ray diffraction and HR-SEM&TEM techniques. The optical energy band gap lies in the interval from 2.7 to 3.6 eV. The photoluminescence spectra present a band with peak at 465 nm, which is indicative of the quantum confinement. The energy peak position (465 nm) is blue-shifted respect to the bulk material (512 nm). Then, one can infer that the energy band gap and the peak intensity vary according to the nominal lithium concentration in the growth solution. An average crystallite size of about 5 nm was estimated by the Brus equation and the Debye-Scherrer formula, and confirm by HR-SEM&TEM measurements.

For the purpose of development of highly energy-efficient light sources, one needs to design highly efficient green, red and yellow phosphors, which are able to absorb excitation energy and generate emissions. In this contribution, we present our results on producing some efficient phosphors with improved luminescence properties. The effects of zinc on the zinc-doped CaTiO3:Eu3+ phosphors have been investigated by varying the zinc concentrations. X-ray powder diffraction (XRD) and Scanning electron microscopy (SEM) characterizations were studies for their structural and morphological analysis. The variation of zinc concentration influences the crystallinity and morphology of the phosphors. The luminescence spectra of (Zn,Ca)TiO3: Eu3+ have been measured. Eu3+: (Zn,Ca)TiO3 have shown five emission transitions of 5D0→7F 0,1,2,3 & 4 located at 580 nm,593nm 615 nm,655 and 704 respectively with excitation at λexci=398nm (7F0→5L6). Moreover, the emitting phosphor developed in this study can be very effectively excited at the wavelengths of 398 nm. The (Zn, Ca)TiO3:Eu3+ can be used as a complementary phosphor in there red region for the white LEDs.

We have performed an analysis on three hydrogenated nanocrystalline silicon (nc-Si:H) based solar cells. In order to determine the impact that impurities play in shaping the material properties, the XRD and Raman spectra corresponding to all three samples were measured. The XRD results, which displayed a number of crystalline silicon-based peaks, were used in order to approximate the mean crystallite sizes through Scherrer's equation. Through a peak decomposition process, the Raman results were used to estimate the corresponding crystalline volume fraction. It was noted that small crystallite sizes appear to favor larger crystalline volume fractions. This dependence seems to be related to the oxygen impurity concentration level within the intrinsic nc-Si:H layers.

HoxEr1-xN (x=0.25, 0.5, 0.75) samples were synthesized by nitriding of HoxEr1-x alloy bars and their thermal conductivity κ were measured. The measured κ values were comparable to those of stainless steel and Er3Ni. Ho0.5Er0.5N showed the highest κ of the present three samples. The thermal diffusivity calculated from the κ and the specific heat indicates that Ho0.5Er0.5N is a very promising regenerator material for the cryocoolers. The electrical resistivity ρ was also measured as a function of temperature.

The photovoltaic materials in solar cells take multiple tasks including absorbing lights, separating the light-induced electron-hole pairs, and consequently transport charges to the corresponding metallic electrodes. These tasks, however, are often mutually conflicting. In particular, a thick PV layer is desired to absorb enough light for creating sufficient light-induced charges, while a thin PV layer is also desired to shorten the charge transport path length insider the PV layer in order to suppress recombination. Using dye-sensitized solar cells as an exploratory platform, this dilemma is mitigated using a non-traditional 3-dimensional (3-D) highly doped fluorinated SnO2 (FTO, core)-TiO2(shell) nanostructured photoanodes. The FTO core serves as conductive core for low-resistance and drift-assisted electron extraction. The thin, conformal and low-doped TiO2 shell layer is coated by atomic layer deposition, which provides a large area for anchoring dyes and maintains a large resistance against recombination.

Metal organic frameworks (MOFs) are porous solids that are potential high performance carbon capture materials. We have mined a hypothetical MOF database for structures that have exceptional low-pressure CO2 adsorption properties. We have applied the REPEAT method to generate accurate atomic charges that regenerate the ab initio electrostatic potential. We show that large scale screening at high accuracy is feasible for thousands of structures. We identify promising synthesis targets, like a simple combination of chrysene linker and vanadium inorganic unit, and examine in detail structural features that make better performing MOFs from those that would not be synthesisable. We find that, although screening large numbers of hypothetical structures is necessary to provide experimental targets, there are limitations to the suggestion of using the this database directly for synthesis targets and propose improvements and constraints that should be incorporated into the design of further generations of such a building-block algorithm to reach the accuracy required for high-quality CO2 adsorption simulation.

The paper describes a virtual OLED (Organic Light-Emitting Diode) laboratory designed to introduce young people to one of the most contemporary devices and technologies which is heavily used in many gadgets familiar to every teenager. In order to make learning science and engineering fun, such an introduction is made in an interactive multimedia-rich format. In the context of touch screen displays for mobile phones., tablets and TVs, the fundamental principles underlying the design, application, and production of OLEDs and OLED-based devices are demonstrated and explained. The lab enables students to practice preparing an OLED and operating an active matrix OLED (AMOLED) online in a virtual environment.

The influence of oxygen content on containerless solidification of Zr80Pt20 alloy has been studied by using conical nozzle levitation (CNL) technique. The doping level of oxygen from 41 to 5450 ppm mass oxygen (PMO) affects the undercooling of the liquid Zr80Pt20 alloy. Time-resolved synchrotron x-ray diffraction revealed that the quasicrystalline (QC) phase precipitated as a primary phase during solidification of the Zr80Pt20 alloy. The amount of the QC phase depends on the oxygen content in the alloy. This indicates that the doping level of oxygen in Zr80Pt20 alloy can be related to the metastable phase formation as well as the glass-formation ability.

Asymmetric (10L) XRD peaks have been employed as a measure of epitaxial quality for aluminum nitride (AlN) nucleation layers (NL) deposited on sapphire substrate. Epitaxial AlN films have been deposited on 2-6” sapphire substrate by reactive sputtering. FWHM of AlN (103) and (105) were found to be an excellent indicator of quality of AlN films for GaN growth. AlN films produced nucleation layers with highly reproducible microstructure and GaN film growth. NLs had in-plane and out-of-plane texture as evident by the pole-figure results and selected area diffraction pattern. Based on electron microscopy results, AlN film thickness for complete atomic ordering was estimated to be 6-7 nm and most of the edge dislocations were seen in the first 20 nm of the film. Excellent thickness and texture uniformity were seen on planar and patterned sapphire substrates. A compressive stress of 2.9±0.2 GPa was seen in our BKM films. The maximum screw and edge dislocation densities of films were found to be ∼3 x 108 cm−2 and ∼9 x 109 cm−2 respectively. The root mean square roughnesses of A-polar films were found to be < 0.3 nm.

Bi2Se3 thin films are imaged in the near-field using spectroscopic scattering type near-field optical microscopy (s-SNOM) at mid infrared laser wavelength region (9-11μm). Single phases Bi2Se3 thin film structures were prepared by mechanical exfoliation on silicon wafers. We report size and wavelength dependent near-field interaction contrasts in both optical amplitude and phase. We show that near-field optical imaging allows material specific identification and characterization of Bi2Se3 exfoliated samples including the confirmation of residual tape presence or removal in stacked films. We describe an alternative “shear exfoliation” sample preparation method which reliably deposits Bi2Se3 without the possibility of adhesive contaminants.

A dislocation-density based crystalline plasticity and specialized finite-element formulations were used to study the behavior of energetic crystalline aggregates. The energetic crystalline material studied was RDX (cyclotrimethylene trinitramine) with a polymer binder and different void porosities. The aggregate was subjected to different dynamic pressures, and the analyses indicate that maximum temperature increases, constrained dislocation densities, and plastic strain accumulations occurred around the void peripheries, which affected overall deformation behavior. These regions of extreme temperature rise and thermal decomposition can result in hot spot formation.

Liposome was synthesized by using mixture of dipalmitoylphosphatidylcholine and cholesterol in the ultrapure water or physiological saline. Phase transformation temperature and vibrational mode of dipalmitoylphosphatidylcholine molecule were detected by using transmission Fourier-transform infrared spectroscopy for aqueous solution, which we developed. The liposomes were fixed on an amorphous carbon mesh for ultra-high resolution transmission electron microscopy observation and stained with platinum thymidine blue. As-prepared liposomes reinforced with cholesterol were spherical in shape with size larger than 100 nm in diameter and still stable in the vacuum. Under the strong electron irradiation condition, the solution enclosed in the liposomes became unstable and then collapsed. On the other hand, the liposome synthesized in the physiological saline sometimes contains crystallized salt. As a result, the liposome shows proper strength to hold wet material in itself in a vacuum and can be used for the transmission electron microscopy observation.