A combinatorial methodology was employed to investigate oxide materials/semiconductor interfaces for future devices. For this purpose, a temperature gradient pulsed laser deposition to find optimum growth condition and transmission electron microscopy for structure and composition analysis were used. Newly proposed the "micro sampling method" with focused ion beam was applied to fabricate the specimen from the interested region in a shorter term. In growing oxide materials on Si substrate, a proper termination was found to be inevitable for avoiding surface oxidation. Arsenic was used to obtain a durable surface of Si in oxygen atmosphere. CeO2 and SrTiO3 were tried to grow and the interfaces were characterized using these method.

We have developed a laser molecular beam epitaxy system capable of the temperature-gradient and/or composition-spread integration of thin films in a substrate. The latter is achieved by using a moving mask system synchronizing with target exchange and laser pulse. The former employs a substrate holder having a controlled asymmetric thermal conduction heated by a focused Nd:YAG continuous wave laser beam. A concurrent x-ray diffractometer can immediately characterize the dependences of the lattice constant and crystalline quality on the film growth temperature and composition. The temperature-gradient method is very useful for revealing an optimum substrate temperature for epitaxial thin film growth. Several other characterization techniques such as magnetic field microscope and parallel transport measurement system developed for characterizing composition-spread thin films are presented.

In order to develop a combinatorial synthesis process for the preparation of thin films from the metal organic chemical sauces, we tried to fabricate Pb(ZrxTi1-x)O3 (PZT) thin films from PT (Pb and Ti) and PZ (Pb and Zr) organic chemical sauces. The PT and PZ solutions were spin-coated onto a Pt/Ti/SiO2/Si substrate layer by layer in different sequences and concentrations, and then the post-annealing was carried out in order to obtain homogenized PZT thin film. Characterizations of the structure, composition and ferroelectric property of the samples were performed by XRD, SEM, XRF, and the P-E hysteresis measurement system. It was found that a homogeneous PZT thin film with single perovskite structure could be obtained without post-annealing treatment if the PZ and PT concentrations were below 0.025M. When the concentrations of PZ and PT were higher than 0.05M, the other phases could be observed besides the PZT phase, even the post-annealing temperature were up to 6000C for more than 14 days. The composition of the PZT films is controllable by changing the ratio of the PZ and PT in the multi-layers. It is concluded that this method could be used to study the other thin film materials.

The Advanced Technology Program (ATP), an agency within the U.S. Department of Commerce's Technology Administration and the National Institute of Standards and Technology, provides co-funding to industry for highrisk/ high-payoff applied research. Companies of any size may apply, and universities or governmental research institutions may partner with industry in ATP projects. Since its inception, the ATP has participated in 468 projects, representing $3B of total industry/government investment. U.S. industry has indicated that ATP has a significant role to play in the area of high throughput R&D. ATP can catalyze the development of lower-cost hardware and software tools to bring leading-edge, generic technologies to more industries, and can facilitate the integration of hardware and software systems. The ATP is currently funding research projects in high throughput discovery of catalysts and polymer coatings, with FY199 project requests of $36. I M over five years. In addition to extramural funding, the ATP has internal funding of the NIST Measurement and Standards Laboratories (MSL). The MSL opportunity in high throughput screening is to develop measurement science to support new parallel methodologies and measurement tools tailored to specific industrial needs; to validate new and existing measurement methods and models using parallel or high throughput approaches; and to demonstrate application of HT methods to new materials and R&D problems; and to develop new standards addressing systems integration issues. The ATP is co-funding research at the NJST MSL in key areas.

Interface structures of SrTiO3/Si were investigated systematically using combinatorial method with growth temperature gradient in pulse laser deposition and cross sectional high resolution transmission electron microscopy . A combinatorial pulse laser deposition with growth temperature gradient system was employed to grow SrTiO3 on Si (100) with various temperatures and oxygen pressures. A high throughput thin foil fabrication system, which is so called micro sampling system, was employed to fabricate thin foils for cross sectional high resolution transmission electron microscope observation. As a result, we have observed a never reported amorphized SrTiO3 layer in the crystalline SrTiO3 thin films grown on Si (100) at growth temperatures above 600°C. From the growth condition dependence studies on the formation of amorphized SrTiO3 layers and the electron energy loss spectroscopy measurements, the origin of the amorphization was concluded as an effect of diffusion of Si from substrate. This is the first observation of a diffusion induced amorphization phenomenon in the crystalline SrTiO3 thin films grown on Si (100). Our results show that at higher growth temperatures, the interface structures of SrTiO3/Si are dominated by the diffusion of Si from the Si substrates.

Because of its fast reversible phase change between a crystalline and an amorphous phase and a corresponding change in optical properties, Ge-Sb-Te alloys are well known as materials for phase change optical data storage [1]. Especially the stoichiometric Ge2Sb2Te5 of the GeTe-Sb2Te3 pseudobinary line is suited for this purpose and already commercially used [2]. Nevertheless, the physical principles of this technique are not yet completely understood. In the presented paper a composition-spread approach was used to deposit Ge-Sb-Te films with compositions around the ternary phase Ge2Sb2Te5. The deposition took place in a UHV sputtering chamber using three magnetron cathodes equipped with pure Ge-, Sb- and Te-targets, respectively, for film deposition. Films were deposited on Si-wafers as well as on Si-Al-5i02 stacks. The resulting composition-spread was analyzed by EPMA-mappings and GI-XRD with respect to composition and structure. The velocity of the phase change was determined using a static tester. The correlation between film constitution and kinetics of the phase change revealed that the change from the initialized crystalline phase to the amorphous phase could be achieved in about 20 ns for optimized compositions. Even slight deviations from this composition resulted in a strong decrease of the phase change velocity. Structural analysis proved the existence of two crystalline phases with cubic and hexagonal structure in the initialized films.

Excitonic properties of high-quality ZnO/Zno,88Mgo.120 multiple quantum wells grown by laser molecular-beam epitaxy were investigated by excitonic absorption spectra taken at temperatures of 5—300 K. Strength of excitonphonon coupling was deduced from temperature dependence of linewidth of the fundamental excitonic absorption band. Significant reduction of the exciton-phonon coupling with decreasing the well width was observed, which is consistent with the confinement-induced enhancement of the exciton binding energy. The thermal shift of the lowest excitonic energy is independent of well width, suggesting the negligible strain effect characteristically inherent in this material. Growth temperature dependence of third-harmonic generation efficiency in (BaxSri1-x)2CuO3 alloyed epilayers is reported. It was found that, within the temperature range adopted in this work, the harmonic generation efficiency of the epilayer grown at higher temperature is larger than that grown at low temperature.

High quality ZnO/Zn1MgO multi-quantum wells (MQWs) have been prepared on lattice-matched ScAIMgO4 substrates by laser-MBE method. Nine pixels of MQWs having different well widths were integrated in the same substrate by means of combinatorial masking techniques, which provided excellent specimens to systematically study the dependence of physical properties of MQWs on well widths. Optically pumped stimulated emission spectra were measured in these ZnO/Zn1MgO multi-quantum wells by using a tunable pulsed dye laser as excitation source. We investigated the pump-intensity dependence of the stimulated emission spectra from 5 to 300 K. At low temperatures, only one peak in the stimulated emission was observed, which could be assigned to the emission induced by exciton-exciton inelastic scattering (P-band). When the temperature increases above 160 K, there appears an additional peak at the lower energy side of the P-band, which was assigned to electronhole plasma emission. However, the emission due to the exciton-exciton scattering still remains up to room temperature. The gain spectrum for a multi-quantum well sample has been obtained by variable stripe method at room temperature. At an excitation intensity of about 2 MW/cm2, the peak gains for the P-band and electron-hole plasma emission are 239 cm1 and 380 cm1, respectively. The exciton binding energy was deduced from the energy difference between the P-band and free exciton band. The exciton binding energies of these samples having different well widths were found to increase with decreasing the well widths due to the quantum confinement effect. This enhancement of exciton binding energy should be favorable for the stability of exciton states at higher temperatures.

Possibility of combinatorial approach to discover a new composition with novel property is discussed mainly focused on the ferroelectric materials. Sol-gel based process has an advantage of easy change of composition to discover a new material with good ferroelectricity and piezoelectric property. Pb(Zr,Ti)O3 with different Zr/(Zr+Ti) composition was successfully prepared by using two methods. One is the mixing at solution state from Pb-Ti and Pb-Zr solutions. The other is the mixing by making Pb-Ti (PT) and Pb-Zr (PZ) solid state layers and the following heat treatment. Mixing at solution state is useful to get a film with a good quality in a shorter time. As a result, sol-gel based process is ascertained to be very effective because of its possibility of making large number of pixels with different composition in a shorter time.

Thin carbon and carbon nitride films exhibit specific optical and mechanical properties which make them promising materials for integrated optics. For this purpose we have investigated the preparation and optical properties of carbon and carbon nitride (CNx) films deposited on silicon substrates. The contribution deals with the study and fabrication of planar optical waveguides on semiconductor (silicon) substrates by the method of Plasma Assisted Chemical Vapor Deposition (PACVD). This waveguide is a carbon or carbon nitride layer deposited in a PACVD apparatus on a layer of silicon oxide, which also provides optical shielding of the substrate and is prepared by the oxidation of a silicon substrate wafer. The carbon as well as carbon nitride layers were fabricated by the reaction of methane, methane and nitrogen or methane and ammonia, respectively, in the PACVD apparatus. The fabricated films were characterized by optical ellipsometry and standard mode spectroscopy at 633 nm. The attenuation of the best sample was less than 0.3 dB/cm. It was found that optical and mechanical properties of films fabricated on the positive and negative electrodes were substantially different. The films deposited on the negative electrode were harder and their refractive index was higher compared with those deposited on the negative electrode. The refractive index of the harder films ranged from 2.2 to 2.6, while for the softer films it ranged from 1 .6 to 1 .8. We proved that it is in principle possible to dope the deposited layers with erbium ionsso that the resulting structures can also be used as active waveguides.

The combinatorial computational chemistry approach was applied to design new types of Fe-based catalysts, which can be used for the production of ecologically high-quality transportation fuels by the Fischer-Tropsch (FT) synthesis. For this purpose, the density functional theory (DFT) was used to investigate the adsorption of 10 intermediate species for methylene formation on Fe-based multi-component catalysts. The energetic, electronic and structural properties of these species on the catalyst surfaces were calculated. The detailed analysis of possible reaction mechanisms was performed from the comprehensive set of binding energies and structures. It was found that Mn, Mo, and Zr could be used as additional elements in the Fe-based catalysts, since one cannot observe a degradation of the adsorption properties of the active sites as well as showing a high sulfur tolerance. The obtained results are in agreement with available experimental data, thus confirming the validity of combinatorial computational chemistry approach. This also illustrates the role in which combinatorial computational chemistry approach can be used to provide data for discovering and designing new catalysts.

Combinatorial chemistry is an efficient technique for the synthesis and screening of a large number of compounds. Recently, we introduced a concept of combinatorial chemistry to computational chemistry for catalyst design and proposed a new method called "combinatorial computational chemistry". In the present study, we have applied our combinatorial computational chemistry approach to the design of methanol synthesis catalysts. Experimentally, it is well known that Cu/ZnO/Al203 catalyst has high activity and several reaction mechanisms of the methanol synthesis process on that catalyst have been proposed. Among those mechanisms, the reaction mechanism through cu-formate and cu-methoxide was strongly supported by experiments. Hence, in the present study we investigated the formation energies of several intermediates during the above reaction mechanism on many catalysts, such as Co, Cu, Ru, Rh, Pd, Ag, Re, Os, Ir, Pt and Au by using density functional calculations. The calculation results suggested that Cu is an active catalyst for the methanol synthesis, which is in good agreement with the previous experimental results. Moreover, Pd, Ag, Ir, Pt and Au are proposed to be effective candidates ofthe most active catalysts for the methanol synthesis.

Organic light-emitting diodes (OLEDs) represent a promising technology for flat-panel displays. Doped ?-conjugated polymer layers have been demonstrated to improve hole injection and lifetime of OLED devices. In this paper, we demonstrate that the work function of such polymers can be continuously adjusted by means of electrochemical doping. This allows to control the hole current through organic semiconducting devices. Injection-limited or bulk-limited device performance can be obtained with the identical semiconductor. We use a combinatorial approach to speed up the optimization process.

Polycrystalline thin films of CuInSe2 have been electrochemically deposited for different sodium citrate concentrations(20-80m Mole). Their optical properties in the near-UV-VIS, JR range, 200-1 l20nm, have been studied. An absorption coefficient (a) as high as 5*2*103 cm-1 is observed at wavelength ?<500 nm. The observed absorption coefficient variation is due to an allowed direct transition with an energy in the range 0.8-3.0eV. The direct valence to conduction band transition energies (Es) is determined from the absorption curves. It is calculated by extrapolating (?hv)2 versus (hv) to the photon energy axis intercept. From such estimations the band gap energy of as-grown film and annealed CuInSe2 films are found to be 1 .00 eV and 1 .04 eV respectively. The short circuit current ISc increases linearly and open circuit voltage V0 increases as a logarithmic function of light intensity. Peak of the spectral response lies at 620nm for 60m Mole sodium citrate annealed CuJnSe2 films. The as-grown film shows higher absorption coefficient than the annealed film.