The purpose of this study is to develop new transparent conducting oxide (TCO) films by using combinatorial approach and to apply them for organic light emitting diodes (OLED) and/or thin film photovoltaic devices. For this, we have explored several TCO films with multi-components and optimized their properties by employing combinatorial sputtering system. For the first, we have fabricated combinatorial libraries composed Zn-In-Sn-O (ZITO) to reduce In content comparing with Sn-doped indium oxide (ITO). The ZITO films showed amorphous structure at the substrate temperature ranged RT∼ 350 °C, high transmittance over 85% at the visible range wavelength, and resistivity as low as 3x10-4∼10-3Ωcm. These results reveal that the ZITO films have indium composition as low as 30∼40% comparing with equivalent ITO films. Furthermore, we have fabricated OLED on glass substrates by using the amorphous ZITO anode. OLED fabricated on amorphous ZITO-coated glasses have exhibited good characteristics comparable to OLED on ITO films. Besides OLED, the amorphous ZITO TCO can be applied for other optoelectronic devices like electronic paper, thin film photovoltaic, and smart window.

This work describes the design and operation of two microfluidic emulsion and foam generators. The difference between the two devices consists in the geometry of the output channel - in one case, we used a straight microchannel, whereas in the second case we implemented a fractal channel output geometry. While both devices can produce highly monodisperse foams and emulsions at high throughput (coefficient of variation CV≈1.5% and production frequency of up to 2.5kHz per channel with a total of 256 micro channels capable, in theory, of operating in parallel), the actual CV at the exit of the device was significantly higher due to interactions between adjacent droplets or bubbles. Using a combination of high-viscosity continuous phase liquid and low-solubility gas phase resulted in improved monodispersity. In these conditions, the fractal output channel geometry resulted in the lowest overall CV (≈3%) at the exit of the device for both foam and emulsion production, due to an inhibition of aging and coalescence phenomena as compared to the straight channel.

High-throughput synthesis and screening rely on structurally diverse catalyst libraries. As a consequence of increased parallelization and integration of reactor and analysis systems, the requirements for new synthesis methodologies include even smaller amounts of samples, e.g. different multi-component mixed oxides in the mg or even μg-range have to be prepared reproducibly and fully automated. We tried to bring solution chemistry, composition spread libraries and a very high sample density together within one approach and tested inkjet printing of materials libraries using sol-gel recipes as synthesis method. Inkjet printing allows the deposition of liquid volumes in the pL range thus enabling the deposition of very small catalyst amounts. For the application of this technique in sol-gel chemistry several restrictions have to be handled, such as viscosity limitations of the printing head. Parameters as solvent, solvent amount, metal precursors, metal salt concentrations, deposition sequences etc. as well as gelification procedures have to be optimized. Catalytic screening relies on porous samples with high surface area to get conversions, which can be detected by HT screening methods. Thus, additionally the recipe itself as well as the support structure has to be optimized. In our first tests we used emission corrected IR thermography for screening.

Successful experimental strategy in the high throughput world requires coordination of the statistical planning of the experimental program with the optimization of the workflow for efficient use of robotic workstation resources.

In order to decrease the use of cobalt element as in LiCoO2,which is mainly used for cathode materials in lithium ion secondary batteries, a newly pseudo-quintenary layered-type Fe-doped Li-Ni-Co-Ti oxides library was created using the combinatorial technology "M-ist Combi system" based on the electrostatic spray deposition method.

The starting materials used were LiNO3, Ni(NO3)2·6H2O, Co(NO3)2·6H2O, Fe(NO3)3·9H2O and TiO2 nano-slurry. These materials were dissolved or dispersed in a mixture of ethanol and butyl carbitol and mixed in a predefined ratio, respectively. Subsequently, each of the mixtures was sprayed and dried on a grounded reaction plate that was heated to 400˚C. The deposited powder was sintered at 700˚C for 5 hours in air atmosphere. Phase identification of the obtained powder library was evaluated by a combinatorial powder x-ray diffractometer. A reaction phase diagram was established from the structure information and chemical composition by ICP-AES measurement.

From all results, single-phase layered-type compounds showed the composition region that included many Co and Ni elements. On the other hand, single phase spinel-type compounds existed in the Ti-rich composition region.

Polymer nanocomposites (PNC) are complex material systems in which the dominant length scales converge. Our approach to understanding nanocomposite tradespace uses Materials Quantitative Structure-Property Relationships (MQSPRs) to relate molecular structures to the polar and dispersive components of corresponding surface tensions. If the polar and dispersive components of surface tensions in the nanofiller and polymer could be determined a priori, then the propensity to aggregate and the change in polymer mobility near the particle could be predicted. Derived energetic parameters such as work of adhesion, work of spreading and the equilibrium wetting angle may then used as input to continuum mechanics approaches that have been shown able to predict the thermomechanical response of nanocomposites and that have been validated by experiment. The informatics approach developed in this work thus enables future in silico nanocomposite design by enabling virtual experiments to be performed on proposed nanocomposite compositions prior to fabrication and testing.

Layered-type LiNi0.4Co0.6-xTixO2 (0≤x≤0.2) were prepared by conventional electrostatic spray deposition method for studying the correlation of crystal structure and electrode property. Starting materials used were LiNO3, Ni(NO3)2·6H2O, Co(NO3)2·6H2O and TiO2 nano-slurry. These materials were dissolved or dispersed in a mixture of ethanol and butyl carbitol and mixed by predefined ratio, respectively. Then, each of mixtures was sprayed and dried on the grounded reaction plate which was heated at 400 °C. Deposited powder was sintered at 700˚C for 10 hours in air atmosphere. Library of LiNi0.4Co0.6-xTixO2 (0≤x≤0.2) was indexed R-3m by powder X-ray diffraction patterns and its chemical compositions from ICP emission spectroscopy method corresponded to the initial composition conditions. From the diffracted intensity ratio of I(003)/I(104) and the structure refinement by Rietveld method, it was found that the proportion of cation mixing effect increased with increasing amount of Ti among of transition metals. And, from the observation by scanning electron microscope and the calculation by Scherrer’s method, the crystallite size decreased with increasing amount of Ti element. From the charge-discharge property of LiNi0.4Co0.6-xTixO2 (0≤x≤0.2) library, LiNi0.4Co0.5Ti0.1O2 showed better cycle behavior among the library.

A high-throughput methodology is applied for the discovery and optimization of novel catalyst formulations to convert readily available hydrocarbon-based JP-8 fuel directly into a lighter hydrocarbon product suitable for portable power applications utilizing LPG-powered fuel cells. In addition to catalytic cracking challenges, JP-8 cracking poses other challenges including high sulfur content (up to 3,000 ppmw) and significant concentration of aromatics, which are precursors to coking. An existing 16-channel high-throughput reactor system was modified for the JP-8 catalytic cracking studies. The catalyst support material was of primary importance in determining cracking activity. Alumina-based catalytic materials demonstrate the greatest activity for conversion of JP-8 to LPG during catalytic cracking at reactor temperatures above 600°C. This is attributed to the importance of acidic reaction sites within the structure of the catalytic support. The addition of noble metals to the alumina-based materials does not yield significant improvements in JP-8 conversion.

We discuss our current research focus on photovoltaic (PV) informatics, which is dedicated to functionality enhancement of solar materials through data management and data mining-aided, integrated computational materials engineering (ICME) for rapid screening and identification of multi-scale processing/structure/property/performance relationships. Our current PV informatics research ranges from transparent conducting oxides (TCO) to solar absorber materials. As a test bed, we report on examples of our current data management system for PV research and advanced data mining to improve the performance of solar cells such as CuInxGa1-xSe2 (CIGS) aiming at low-cost and high-rate processes. For the PV data management, we show recent developments of a strategy for data modeling, collection and aggregation methods, and construction of data interfaces, which enable proper archiving and data handling for data mining. For scientific data mining, the value of high-dimensional visualizations and non-linear dimensionality reduction is demonstrated to quantitatively assess how process conditions or properties are interconnected in the context of the development of Al-doped ZnO (AZO) thin films as the TCO layers for CIGS devices. Such relationships between processing and property of TCOs lead to optimal process design toward enhanced performance of CIGS cells/devices.