We have demonstrated strong multimode photonic microresonator and nanoparticle interactions by using an integrated micro disk resonator from through port of the laser coupling bus waveguide. In addition to the fundamental resonance mode, disk resonator has higher order resonance modes. The excited higher order mode has a node at the position where the electromagnetic energy of the fundamental mode is close to a maximum. Here we report that a self referencing mechanism can be achieved by simultaneous excitation of both fundamental and 2nd order micro disk optical resonance modes. Additionally, we are able to measure the area around the maximum of the fundamental resonance mode and the node of the higher order mode, which have overlaps in the disk. In this work, we used on chip disk microresonator as the example, as a variety of types of optical microresonators have been investigated; we used nanoparticle to interact with the two optical resonance modes excited by the coupling bus waveguide, where the nanoparticle can be either dielectric materials or metallic materials. The strong photonic microresonator and nanoparticle interactions have variety of applications for optical switches, waveguides and detection. The self-referencing characteristics of the two optical resonance modes have potential to achieve photonic functions independent of external perturbation, such as temperature change.

There has been much interest in the last few years on materials reinforced with nanometer scale particles. These so-called nanocomposites can exhibit hybrid properties derived from its components. One of the most promising nanocomposites is that based on polymers reinforced with single-layered carbon sheets named graphene. The reason is that graphene can significantly improve the physical properties of the polymeric material once it is completely dispersed in the matrix. In this work nylon/graphene nanocomposites were prepared starting from the synthesis of graphite oxide (GO). Direct oxidation of graphite powder was utilized to produce GO. That is, the oxidation reaction produced graphite layers with functional groups containing oxygen. The aim was to increase the polarity of GO to enable a good dispersion in polar solvents. Then, nylon/graphene nanocomposites were prepared by reducing GO in the presence of nylon. Finally, non-woven membranes, with nanometer sized filaments, of nylon/graphene were electrospun. The morphology and microstructure of the nanocomposites was investigated via electron microscopy and X-ray diffraction.

In this study indium tin oxide (ITO) thin films have been deposited by RF sputtering technique on quartz substrate. In all cases, the substrate was heated during deposition. Thin film deposited under various process conditions, shows characteristic XRD reflection corresponding to the (222) crystal orientation. Transmittance of the film has been measured for the wavelength range from 190 to 3300 nm. Average transmittance of 84.4%, 90.2% and 85.3% for wavelengths up to 800 nm, 2500 nm and 3300 nm respectively has been obtained. The resistivity in this case is found to be as low as ∼10 × 10-4 Ω-cm. Our study is focused on controlling the resistivity of the deposited film, without compromising transmittance in the near infra red (NIR) region of the spectrum. Substrate heating during deposition is found to result in films with grains which are oriented in (222) direction predominantly. Moreover, the average grain size is increased with subsequent annealing. It has been observed that though the transmittance for the samples doesn’t vary substantially upon annealing the resistivity decreases by several factors.

Nanostructured surfaces have demonstrated extraordinary capacity to influence protein adsorption and cellular responses, although the mechanisms behind such capacity are still not clear to date. In the present study, the role of surface energy associated with nanostructured stiff surfaces in modulating fibronectin and consequently osteoblast (OB, bone forming cells) responses was investigated. Nanocrystalline diamond (NCD) and submicron crystalline diamond (SMCD) films with controllable surface energy were prepared by microwave-enhanced plasma chemical vapor deposition (MPCVD) techniques. Fibronectin adsorption on the diamond films with varied surface energy values was measured via the enzyme-linked immunosorbent assay (ELISA) and the relationship between the surface energy and fibronectin adsorption was studied. OB aggregates (each containing 30∼50 cells) on the NCD with varied surface energy values were also studied. The results indicated that fibronectin adsorption on nanostructured surfaces was closely related to both surface energy and material microstructures, and osteoblast spreading and migration on stiff nanosurfaces are surface energy-driven processes.

Al2O3 and AlN nanotubes were fabricated by depositing conformal thin films via atomic layer deposition (ALD) on electrospun nylon 66 (PA66) nanofiber templates. Depositions were carried out at 200°C, using trimethylaluminum (TMAl), water (H2O), and ammonia (NH3) as the aluminum, oxygen, and nitrogen precursors, respectively. Deposition rates of Al2O3 and AlN at this temperature were ∼1.05 and 0.86 Å/cycle. After the depositions, Al2O3- and AlN-coated nanofibers were calcinated at 500°C for 2 h in order to remove organic components. Nanotubes were characterized by using X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). AlN nanotubes were polycrystalline as determined by high resolution TEM (HR-TEM) and selected area electron diffraction (SAED). TEM images of all the samples reported in this study indicated uniform wall thicknesses.

A phase field model is developed to investigate the formation of a solid electrolyte interface layer on the anode surface in lithium-ion batteries. Numerical results show that the growth of solid electrolyte interface exhibits power-law scaling with respect to time, and the growth rate depends on various factors such as temperature, diffusivity of electrons, and rates of electrochemical reactions.

Polymer/carbon nanotube (CNT) composites show next to improved mechanical, thermal, and electrical properties also sensitivity to external stimuli. A detection of environmental condition changes is possible, if it affects the electrically conductive CNT network inside the insulating polymer matrix. In case of liquid sensing, swelling of the polymer matrix due to contact with organic liquids and interactions between solvent molecules and CNTs result in a local gap enlargement between individual CNTs and/or CNT clusters, resulting in a detectable increase of electrical resistance. Accordingly, CNT based conductive polymer composites (CPCs) represent very promising candidates for the design of smart components capable of integrated monitoring. In this presentation we focus on their use as leakage detectors for organic solvents.

The sensor concept, as well as the underlying mechanism, is demonstrated for polycarbonate (PC)/CNT based CPCs on compression-molded samples. The selectivity as an important sensor property will be discussed in context with the Hansen solubility parameters and the solvent molecule’s size. The time dependent electrical response characteristic upon immersion depends on the diffusion kinetics of the specific solvent molecules into the CPC. A model allowing the calculation of the time dependent relative resistance (Rrel ) change is presented considering several factors like the diffusion parameters, composite characteristics like initial resistance and geometrical values of the sensing sample. Using this model, Rrel curves of PC/MWCNT composites were simulated which fit very well the experimental data.

In order to examine the production of first prototype large area sensors, fibers and textiles based on composites of different polymer matrices with multi-walled carbon nanotubes (MWCNT) were produced. MWCNT containing fibers based on poly lactic acid (PLA) and polycaprolactone (PCL)/ polypropylene (PP) blends were produced by melt spinning and textile fabrication was performed for PCL/PLA blends. For all presented composite systems the electrical response characteristics was analyzed for various organic solvents.

Wastewaters often contain offensive cations. Because of their high affinity for water, it is difficult to remove those using conventional solvents for liquid- liquid extraction [1]. Hydrophobic ionic liquids may provide a useful extraction process. Because the properties of ionic liquids are turnable, it may be possible to identify some ionic liquids that have low viscosity, very low solubility in water, and high affinity for select metal ions [2]. In this sense in this work liquid- liquid extraction of dilute Zn ions from water was performed near room temperature with two ionic liquids (IL). Distribution coefficients are reported for Zn ions extracted with bromide 1-hexyl-pyridinium and bromide 1-octyl-pyridinium diluted in decanol. The extraction has been studied, and these confirmed that the metal extraction proceeds via a cation – exchange mechanism. Furthermore, stripping of Zn (II) from ILs into an aqueous phase by sulfuric acid (1 M) and recycling of the extracting ILs phase was successfully accomplished.

Metal oxide (MO) films (ZnO and CuO) were synthesized by hydrothermal methods and treated with hydrogen and oxygen plasmas. From uv-visible transmittance spectra, we have found that the optical band gaps of MO films blue-shifted with hydrogen plasma treatment, but red-shifted with oxygen plasma treatment. By alternating the treatment sequence of hydrogen and oxygen plasmas, the MO optical band gap values can be reversibly tuned with the tunable ranges as wide as 80 and 550 meV for ZnO and CuO, respectively. The mechanism for reversible tuning of optical property is proposed based on the results of optical emission, X-ray diffraction, and scanning electron microscopy characterization. Compared to conventional metal ion doping and high temperature annealing methods, the use of low-temperature hydrogen and oxygen plasmas is more environmentally friendly.

We correlated the texture morphology and the solar cell properties by measuring the distribution in the texture morphology. As a result, the short-circuit current ISC was approximated across various types of substrates by the standard texture height. Furthermore, we investigated the texture morphology from the point of view of the electrical effects. With regard to this point, the open-circuit voltage VOC was correlated to the steepest texture angle. Therefore, we consider that the both of the ISC and the VOC can be improved by controlling the distribution in the texture morphology.

We demonstrate an easy way of decorating MWCNTs with CdS and CuxSy using the solvothermal method.

The carrier transport properties in the emissive layer of phosphorescent polymer organic light-emitting diodes (OLEDs) were observed by time-of-flight (TOF) mobility measurements. The hole and electron mobilities in carrier transport polymer without iridium complexes were measured with high levels, 3 × 10-4 cm2/Vs (hole) and 1 × 10-3 cm2/Vs (electron), of non-dispersive transport. The hole and/or electron transport properties were degraded when the iridium complexes were included in the phosphorescent polymers. The complexes acted as a trap in the phosphorescent polymers when the energy levels of the iridium complexes were lower than that of the carrier transport polymer.

We describe the properties of nano-crystalline silicon based alloy (nc-SiXY) prepared by a very high frequency plasma enhanced chemical vapor deposition (VHF-PECVD) technique with silane (SiH4) and XY gas mixtures and diluted in hydrogen (H2) at low deposition temperature. Varying the gas ratio among SiH4, H2 and XY gasses could alter the optical bandgap and structure. The nc-Si films with high crystalline volume fraction were first prepared, and then the XY gasses were added in order to tune the microstructure and opto-electronic properties of this nano-crystalline silicon based alloy. We have characterized the materials using UV-VIS-NIR, Raman, Constant Photocurrent Method (CPM), dark- and photo-conductivity. As XY gas flows were increased, the optical bandgap of nc-SiXY films increased, while its crystalline volume fraction and conductivity decreased. With proper control of the silane concentration, XY/SiH4 gas ratio, and deposition pressure, we have fabricated the nc-SiXY film with optical bangap of about 1.5eV. Applying this material as the absorber layer in p-i-n devices with configuration of textured ZnO/nc-p+/nc-SiXY/a-n+/Ag, the efficiency is 7.25% (Voc=0.616V, Jsc=17.69mA/cm2, FF= 0.666) with thickness of ∼0.8μm.

Tropical climate create ideal conditions for the development of microbial communities associated with biodegradation of historic buildings made with stony materials. This is the case of Fort San Carlos, a historic colonial building representative of military tendencies during the XVII century in San Francisco de Campeche City. In this study the Polymerase Chain Reaction (PCR), was used to identify microorganisms related with the biodegradation of its masonry structure. Specific primers for amplification of 16S and 18S ribosomal RNA genes were used for organisms identification by PCR. Amplification products were sequenced and after that compared with GENBANK nucleotide database using-BLASTn. Results indicated that microbial communities associated to biodegradation of the Fort San Carlos are bacteria from the Phyla Cyanobacteria, Proteobacteria and Actinobacteria.

We report CdTe/CdS solar cell with CdTe layer grown by sputtering method. A controlled etch and anneal process on the sputter-grown CdTe films was performed to increase the average grain size of the film. The process involved dipping the CdTe films in a saturated solution of cadmium chloride (CdCl2) in methanol (2.08 gram in 100 ml) followed by a 30 minute annealing at 400 °C. We performed various experiments on this process by varying the dipping times, drying process and annealing times and analyzed the resultant films using Scanning Electron Microscopy (SEM). We could see a clear increase in grain size from 200 nm to 5 μm after CdCl2 treatment. The process also increased the overall roughness of the sample so that more light is absorbed than reflected. We prepared solar cells using CdTe as p-type layer and CdS as n-type layer. The efficiency of the cell improved from 1.1% to 4.2% after air annealing. The effect of air-annealing is studied by means of quantum efficiency measurement.

Polymer assisted deposition (PAD) has been reported as a novel CSD approach for thin film growth with improved homogeneity and long stability by forming a metal polymer species. It also offers the interesting possibility of having a library of PAD solutions for each precursor metal and obtaining the required composition by simple mixing. Another potential advantage is the increase in thickness since mechanical stresses are expected to be alleviated during shrinkage in the metalorganic decomposition by the metal-polymer network.

Cerium oxide films on YSZ single crystals were grown from water-based solutions containing cerium nitrate, polyethyleneimine and complexing EDTA, in order to explore the benefits of using the PAD approach for growing buffer layers in coated conductors. An ultrafiltration step was performed to remove the non-coordinated species in solution. The degree of purification and efficiency in the cerium recovery was investigated by different techniques. TGA-DTA analysis was used to provide guidance to the best thermal profiles in different atmospheres and specially to diminish the adverse effects of exothermic events during decomposition. Microstructural evolution was tracked by AFM and TEM, while epitaxial fraction was followed by X-ray diffraction. The results show the high importance of choosing the proper atmosphere and the need for tuning of heating ramps to obtain dense, flat and epitaxial ceria films by PAD.

We demonstrate that the anisotropic optical response of metal (cobalt) slanted columnar thin films (STF) at THz frequencies strongly depends on the dielectric properties of the dielectric ambient surrounding the slanted columnar thin films. An effective medium dielectric function approach is used to describe the combined optical response of metal slanted columnar thin film and dielectric ambient. Our observations indicate that metal (cobalt) slanted columnar thin films can be used as sensors which will enable detection and characterization of minute amounts of dielectrics at THz frequencies, such as for flow-based detection of liquid chemical constituents.

Changes in critical current properties depending on growth temperature (T s) were clarified for Ba-Nb-O-doped YBa2Cu3Oy (Y123) films deposited by YAG- and excimer-PLD. Due to the introduction of Ba-Nb-O-nanorods, a vortex-Bose-glass-like behavior emerged as irreversibility lines and in-field critical current densities (J cs) were improved. Crossover magnetic fields (B cr) and in-field J cs increased with the increase in T s for the Y123 films with nanorods. These T s-dependent critical current properties were attributable to the changes in morphology of the nanorods with T s and were independent of laser source in PLD apparatuses. For the fabrication of RE123 coated conductors containing nanorods, optimization of T s with taking both materials of RE123 matrix and nanorod into account is necessary to achieve higher in-field J c.