Combinatorial chemistry has been developed as an experimental method where it is possible to synthesize hundreds of samples all at once and examine their properties. Recently, we introduced the concept of combinatorial approach to computational chemistry for material design and proposed a new method called `a combinatorial computational chemistry'. In this approach, the effects of large number of dopants, substrates, and buffer layers on the structures, electronic states, and properties of metal oxide electronics material is estimated systematically using computer simulations techniques, in order to predict the best dopant, substrate, and buffer layer for each metal oxide electronics materials.

Sol-gel processing consists several variable parameters during materials synthesis and post processing steps. The sol-gel synthesis is rather sensitive for the parameters such as pH, temperature, type of catalyst, reaction time etc. However, this sensitivity can be taken as an advantage when developing and studying new materials and their properties. Furthermore, since the sol-gel technology mainly describes the fabrication of solid state materials from a liquid phase by applying metal alkoxides or metal salts as precursors, the post processing such as sintering has critical effects on the final form and properties of the solid material. Combinatorial chemistry and methods are valuable tools to estimate the effects of different variables and to build-up combinatorial libraries for the sol-gel technique. This paper generally describes potentials and the usage motivation of combinatorial chemistry in the sol-gel technology by taking into account some major steps in the synthesis and processing which are valuable for the estimation of the final product properties. Different kind of post processing steps in the combinatorial manner are studied in details. As an example the post processing of sol-gel derived semiconductor oxides and photosensitivity of hybrid sol-gel glasses are presented. The combinatorial treatment and measurement methods for these materials are explained.

TiO₂ thin films doped with various transition metals were systematically fabricated by combinatorial laser MBE technique. Alternating KrF excimer laser ((lambda) equals 248 nm) ablation of TiO₂ and Ti_1-x M_xO₂ (M equals transition metal) was employed to deposit combinatorial library of 18 samples for each dopant with different concentrations. Anatase films with c-axis orientation were grown epitaxially on SrTiO₃(001) substrate while the rutile phase films with a-axis orientation were on Al₂O₃(0001) substrate. Solid solubility of transition metals in both the phases was determined by X-ray diffraction. The anatase phase was found to dissolve the transition metals in higher concentrations than rutile phase. The parallel evaluation of the photocatalytic activity of the doped TiO₂ in combinatorial libraries was performed with respect to photo-decomposition of water in presence of a small amount of oxidizing or reducing agent which induced pH changes on the pixels. The high throughput evaluation of combinatorially deposited photocatalytic thin films was realized by adopting a potentiometric pH field effect transistor for sensing such pH changes.

We have developed the simultaneous optical measurement method by using the optic fiber bundles specialized for combinatorial samples combined with the arrayed charge coupled devices. This also can be used for experiments done at cryogenic temperatures. The smoother dependence upon various growth parameters could be obtained by virtue of the combinatorial fabrication method. Our present study revealed that the use of lattice-matched ScAlMgO₄ substrates greatly improved the optical (excitonic) properties of epitaxial ZnO layers as well as ZnO-based quantum wells. The improved points by virtue of lattice-matching are as follows: (1) reduction of the nonradiative decay rate of excitons, (2) settlement of the undesired criterion of well- width, the limit to which the relevant quantum confinement can be achieved, (3) bright excitonic photoluminescence at room temperature as the result of increased quantum efficiency.

Vacuum evaporation (VE) and pulsed laser deposition (PLD) were examined as film preparation methods for (pi) - conjugated polymers with photoluminescent property. A variety of (pi) -conjugated polymer films were deposited under various conditions within a single experiment by using combinatorial mask technology for optimization of preparation conditions, e.g. evaporation temperature of VE and laser power density of PLD.

This report is a collection point for non-proprietary business and technical information gleaned from industry input, for example as obtained at an Industry Probe Working Group Discussion held in March, 1998, public ATP Workshops held November 18, 1998 in Atlanta, GA, November 16, 1999 in San Jose, CA, as well as ATP's participation in many industrial forums in the last two years. Complete review articles can be found in the references.

Combinatorial chemistry is an efficient technique for the synthesis and screening of a large number of compounds. Recently, we introduced the combinatorial approach to computational chemistry for a catalyst design and proposed a new method called `a combinatorial computational chemistry'. In the present study, we have applied this `combinatorial computational chemistry approach' to the design of deNO_x catalysts. Various ion-exchanged ZSM-5 are good candidates as catalysts for removal of nitrogen oxides (NO_x) from the exhaust gases in the presence of excess oxygen. Here we described the screening of the exchange cations in ion- exchanged ZSM-5 which are strong against poisons. In the deNO_x reaction NO₂ molecules play an important role in the formation of reaction intermediates with reductants. Here, we estimated adsorption energies of NO₂ on various ion-exchanged ZSM-5 catalysts. The difference in the adsorption energies of NO₂ and poisons such as water and SO_x molecules has been compared. Cu⁺, Ag⁺, Au⁺, Fe²⁺, Co²⁺ and Cr³⁺-ZSM-5 were found to have a high resistance to water and SO_x molecules during the deNO_x reaction.

We report high-throughput optimizations for various material parameters of Mg,Zn_1-xO and Zn_1-xCd_xO alloy films, Al-doped ZnO films, Mg_xZn_1-xO/ZnO single quantum wells and superlattice structures with using combinatorial laser MBE. Combinatorial chips including nine thin film pixels were grown on lattice-matched ScAlMgO₄ (0001) substrates by switching the mask patterns and targets during pulsed laser deposition.

For the rapid structural characterization of combinatorial epitaxial thin films, we developed an X-ray diffraction system. A convergent X-ray beam from a curved crystal monochromator is focused on sample surface about 0.1 mm X 10 mm in size. Diffraction patterns of this area are simultaneously observed on the 2D detector within a few degree. Thus, rocking curve profiles of combinatorial epitaxial thin films for one-column pixels can be measured rapidly with Bragg peak of substrate; the measurement time depends on the film thickness, but the most cases are within one minute.

Combinatorial approach was employed to fabricate single and bi- layer films of (pi) -conjugated polymers for exploring their new electrical and/or photofunctional properties. (pi) -conjugated polymer sources were synthesized from organo-nickel or -palladium complexes, and evaporated by vacuum evaporation. A variety of films with different thickness, those with a bi-layer structure, and so on were integrated on substrates such as ITO coated glass, quartz glass, and silicon wafer by defining the area of the film deposition using physical masks. IR measurements revealed that the evaporated single layer polymer film retained the bulk structure and that of the double layered films gave absorption as the sum of single layered films. As the first step for exploration of electroluminescent device, various bilayer films composed of p-type and n-type (pi) -conjugated polymer layers were fabricated combinatorially on ITO coated glass substrate and their electrical properties were investigated. Diode property was observed in the (ITO/PPP(poly(p-phenylene)/PPy (poly(pyridine- 2,5-diyl)/Ag) heterostructures and their current density was mainly dependent on the thickness of PPy. Optimization of metal employed for electron injection was carried out by combinatorial technique. Smaller turn-on voltage was observed for Mg than for Ag and In. This result can be explained on the basis of work function of metals and LUMO energy of PPy. Insertion of thin LiF layer between the PPy and metal electrode resulted in more smooth electron injection.

The growth of mainly c-axis oriented YBa₂Cu₃O_7-x thin films on a YSZ and CeO₂ buffer layers deposited on the R-plane sapphire substrates was investigated. Both films were grown by a pulsed laser deposition technique from the multi-component targets by in- situ successive target changing during deposition. The structure and compositional properties were studied by X-ray diffraction and pulsed laser spectroscopy, respectively. The electrical resistance and the surface impedance were measured by a four-probe DC-method and by the H₀₁₁ mode of a high-Q copper cavity at 135 GHz, respectively. A T_c is congruent to 86 K and (Delta) T_c is congruent to 4.1 K and R_s is congruent to 680 mOhm at 20 K for YBa₂Cu₃O_7-x thin films with YSZ buffer layer and T_c is congruent to 88.8 K with (Delta) T_c is congruent to 1.7 K and R_s is congruent to 105 mOhm at 20 K for YBa₂Cu₃O_7-x thin films with CeO₂ buffer layer were obtained by an research conditions of deposition for both films. Comparison of the films characteristics grown on sapphire substrates without any buffer layer showed a good perspective of the discussed technique for large area YBa₂Cu₃O_7-x thin films and multi-layer structures growth on sapphire too.

This report is focused on the water-repellant properties of TiO₂ and its mixed films with adding certain oxides or fluorides. It is well known that TiO₂ films and powders can be used as a water splitting coating due to its photocatalytic reaction. With the addition of the second material, the absorption band and the microstructure of TiO₂ films are changed, which will influence their photocatalytic properties. Mixed films based on TiO₂ with various compositions were deposited on unheated BK7 glass substrates by e-beam gun coevaporation technique with ion bombardments. Some of the films were also deposited at a glass substrate temperature of 300 degree(s)C without ion assistance. The degrees of water repellence of these films before and after UV irradiation were evaluated in terms of the contact angle of the deionized water on the coating surface. The correlation between the composition, UV-light exposure time and the water-repellant properties of the mixed films ere evaluated and discussed.