We report on the formation of highly flexible and transparent TiO2/Ag/ITO multilayer films deposited on polyethylene terephthalate substrates. The optical and electrical properties of the multilayer films were investigated as a function of oxide thickness. The transmission window gradually shifted toward lower energies with increasing oxide thickness. The TiO2 (40 nm)/Ag (18 nm)/ITO (40 nm) films gave the transmittance of 93.1% at 560 nm. The relationship between transmittance and oxide thickness was simulated using the scattering matrix method to understand high transmittance. As the oxide thickness increased from 20 to 50 nm, the carrier concentration gradually decreased from 1.08 × 1022 to 6.66 × 1021 cm−3, while the sheet resistance varied from 5.8 to 6.1 Ω/sq. Haacke's figure of merit reached a maximum at 40 nm and then decreased with increasing oxide thickness. The change in resistance for the 60 nm-thick ITO single film rapidly increased with increasing bending cycles, while that of the TiO2/Ag/ITO (40 nm/18 nm/40 nm) film remained virtually unchanged during the bending test.

The effects of polymer substrates on the interfacial structure and the thermal stability of Ga-doped ZnO (GZO) thin films were investigated. The GZO thin films were deposited on polyethylene terephthalate (PET) and polyethylene naphthalate (PEN) substrates by rf-magnetron sputtering at room temperature, and thermal stability tests of the GZO thin films on the polymer substrates were performed at 150°C up to 8 h in air. Electrical and structural characterizations of the GZO thin films on the PET and the PEN substrates were carried out, and the origins of the stable interfacial structure and the improved thermal stability of the GZO thin film on the PEN substrate were discussed.

In this study, we investigated the effect of two oxygen concentrations (5 and 20%) during in vitro maturation (IVM) and during in vitro culture (IVC) on porcine embryo development and analysed differences in gene expression between cumulus–oocyte complexes matured under 5 or 20% oxygen and the resulting blastocysts cultured under 5% or 20% oxygen following parthenogenetic activation. There was no significant difference in oocyte maturation rate. However, the numbers of resulting blastocysts were significantly increased in the 5% IVC group compared with the 20% IVC group. Moreover, the M20C5 treatment group (23.01%) supported greater blastocyst development compared with the M5C5 (14.32%), M5C20 (10.30%), and M20C20 (17.88%) groups. However, total cell numbers were not significantly different among groups. According to mRNA abundance data of multiple genes, each treatment altered the expression of genes in different patterns. GLUT1, G6PD and LDHA were up-regulated in cumulus cells that had been matured in low oxygen, suggesting a higher glucose uptake and an increase in anaerobic glycolysis, whereas cyclin B1 (CCNB) and MnSOD (Mn-superoxide dismutase) were upregulated in cumulus cells that had been matured in high oxygen, which suggests a higher activity of mitosis-promoting factor and antioxidant response. In spite of these differential effects on cumulus cells, oocytes could mature normally regardless of different oxygen concentrations. Therefore, it can be concluded that high oxygen concentration during in vitro maturation and low oxygen during in vitro culture may alter the expression of multiple genes related to oocyte competence and significantly improves embryo development (p < 0.05) but not blastocyst quality.

When a drop is deposited on a superhydrophilic micropillar array, the upper part of the drop (referred to as the bulk) collapses while the bottom part penetrates into the gaps of the array, forming a fringe film. Here we quantify the early stage dynamics of this process using a combination of experiment and theory. We show that the circular front of the fringe film spreads like t1/2, t being time, when coupled to the bulk flow. However, the film is found to advance like t1/3 through faceted zippering in the absence of the bulk. We then show that the spreading of the bulk and the entire drop footprint follows a power law (t1/4) that is different from Washburn's law. This work can be a starting point to completely understand the spreading of liquids on superhydrophilic surfaces and opens questions specific to superwetting behaviour including the criteria to determine whether the fringe film will expand through lateral zipping or advance radially outwards.

Recent studies by a number of research groups have shown that the structure of epitaxial BiFeO3 (BFO) films changes drastically as a function of substrate-induced biaxial compression, with the crystal structure changing from one being nearly rhombohedral (R-like) to one being nearly tetragonal (T-like), where the “T-like” structure is characterized by a highly enhanced c/a ratio of out-of-plane c to in-plane a lattice parameters. In this work, we show that the critical compressive strain σc necessary to induce this transition can be reduced significantly by substituting 10% Ba for Bi [Bi0.9Ba0.1FeO3−δ (BBFO)] and that the “T-like” phase in both BBFO and BFO is stable up to the decomposition temperatures of the films in air. Furthermore, our results show that the BBFO solid solution shows clear ferromagnetic properties in contrast to its undoped BFO counterpart.

We investigated the pressure dependence of the inductive coupled plasma (ICP) oxidation on the electrical characteristics of the thin oxide films. Activation energies and electron temperatures with different pressures were estimated. To demonstrate the pressure effect on the plasma oxide quality, simple N type metal-oxide-semiconductor (NMOS) transistors were fabricated and investigated in a few electrical properties. At higher pressure than 200mTorr, plasma oxide has a slightly higher on-current and a lower interfacial trap density. The on-current gain seems to be related to the field mobility increase and the lower defective interface to the electron temperature during oxidation.

The sequential segmental approach is now universally used in the diagnosis of congenital heart disease. Its utilization during fetal sonography has not been well described. In this review, we show how the fetal heart can be approached in a sequential segmental manner by using six basic sonographic views. The transverse view of the fetal upper abdomen is obtained to determine the arrangement of the abdominal organs, which, in most cases, provides the important clues to the determination of the atrial arrangement. The four-chamber view is obtained to evaluate the atrioventricular junctions. The views of the left and right ventricular outflow tracts are obtained to evaluate the ventriculoarterial junctions. The three-vessel view and the aortic arch view are obtained for the evaluation of the arrangement and size of the great arteries, which provides the additional clues to the diagnosis of the abnormalities involving the ventriculoarterial junctions and the great arteries. The standard protocol to acquire these six basic views is also introduced.

The syntxhesis, photo-physics, and electroluminescence of new types of Iridium(III)-encapsulated dendrimers are described. Thus, four different iridium complexes [Ir(III)(C^N)2(LX), Blue-DCBP, Green-DCBP, Yellow-DCBP, and Red-DCBP] with ancillary ligand tethered to the CBP dendritic unit were synthesized and investigated for their photo-physical properties. A large enhancement in electroluminescence performance was observed by using these dendrimers as host/dopant hybrid materials in layered emitting diodes. In particular, host/dopant ratio can be systematically adjusted by varying dendritic generations. These results demonstrate that new Ir(III)-encapsulated dendrimers can be used as potential single-layer materials for organic light emitting diodes. Large difference in the intra-molecular charge transfer phosphorescence quantum yields and electroluminescence effiencies were observed among dendriritic generations.

Carbosilane dendrimers adorned with either triarylamine or carbazole units in their periphery exhibit novel electrochemical behavior in which the electrochemical deposition is controlled by dendrite generation. In addition, the deposited layers remained intact in the depositing solvent, methylene chloride, allowing a second layer to be deposited on top of the first layer. We have sought to establish the suitability of this electrochemical deposition technique for use in the construction of multi-layer OLEDs, which cannot be fabricated via conventional spin-coating with a polymeric precursor. Thus, the electrochemical deposition-based process could potentially offer an ideal combination of deposition control on the one hand and multi-layer fabrication on the other. We report herein the novel electrochemical deposition behavior of arylamine or carbazole end-capped carbosilane dendrimers of the type GnNPB or GnCBP (n = 1-4) and their use for the formation of multi-layer devices for OLEDs.

The reaction sequence and microstructure evolution of a crystalline MgB2 layer were examined during ex situ annealing of evaporated amorphous boron (a-B) with Mg vapor. Mg was found to migrate rapidly into the a-B layer in the initial stage of reaction with a uniform concentration of about 12 at.%. A thin layer of crystalline MgO was observed at the interface between a-B and the Al2O3 substrate. It was identified that an MgB2 layer started to form at the surface by the nucleation and growth process in polycrystalline form. It appears that there exists two distinct growth fronts in the MgB2 layer: one lying at the surface and the other lying at the interface between the MgB2 layer and the a-B. The microstructural evolution of this layer showed significant differences depending on the location of these two growth fronts.

SiC nanowire was grown by APCVD using single precursors. Grown SiC nanowires had 10∼60nm diameters and lengths of several micrometers. Nanowire's diameters and lengths were varied with kind of catalysts. Nanowire's growth scheme was divided by two regions with diameter of nanowire. At first region, nanowire was grown by VLS (vapor-liquid-solid) mechanism, but at the second region, nanowire growth was made by VS (vapor-solid) reaction. These differences were made from limitations of growth rate and deactivation effects. Growth temperature, time and flow rates of source gases were affected nanowire's diametesr and its lengths. And kind of catalysts, coating methods and precursors were affected growth direction and microstructures too.

Using variable-angle spectroscopic ellipsometry, we measure the pseudo-dielectric functions of as-deposited and annealed SiO2/SiOx multilayers (MLs). The SiO2(2nm)/SiOx(2nm) MLs have been prepared under various deposition temperature by ion beam sputtering. The annealing at temperatures ≥ 1100°C leads to the formation of Si nanocrystals (nc-Si) in the SiOx layer of MLs. Transmission electron microscopy images clearly demonstrate the existence of nc-Si. We assume a Tauc-Lorentzian lineshape for the dielectric function of nc-Si, and use an effective medium approximation for SiO2/nc-Si MLs as a mixture of nc-Si and SiO2. We successfully estimate the dielectric function of nc-Si and its volume fraction. We find that the volume fraction of nc-Si decreases after annealing, with increasing x in as-deposited SiOx layer. This result is compared to expected nc-Si volume fraction, which was estimated from stoichiometry of SiOx.

SiOx nanowire were synthesized using VLS (vapor-liquid-solid) and SLS (ssolid-liquid-solid) growth mechanism. Grown nanowires had a different shapes by the kind of substrates and kind of catalysts. Diameters and lengths of grown nanowires were varied with growth conditions. By vapor evaporation method, used substrates effected growth scheme and density of nanowires because of differences of catalyst nucleation characteristics. Grown nanowires showed different microstructures and optical properties. By catalyst evaporation method, various shapes of SiOx nanowires were grown. These shapes of nanowire were formed by the typical reaction of catalyst and Si source. Measured optical properties show blue luminescence about 430nm because of oxygen defects in the nannowire.

Si/SiO2 multilayers (MLs) have been prepared under different deposition temperatures (TS) by ion beam sputtering. The annealing at 1200°C leads to the formation of Si nanocrystals in the Si layer of MLs. The high resolution transmission electron microscopy images clearly demonstrate the existence of Si nanocrystals, which exhibit photoluminescence (PL) in the visible range when TS is ≥ 300°C. This is attributed to well-separation of nanocrystals in the higher-TS samples, which is thought to be a major cause for reducing non-radiative recombination in the interface between Si nanocrystal and surface oxide. The visible PL spectra are enhanced in its intensity and are shifted to higher energy by increasing TS. These PL behaviours are consistent with the quantum confinement effect of Si nanocrystals.

The silicidation reactions and thermal stability of Co silicide formed from Co-Ta/Si systems have been investigated. In case of Co-Ta alloy process, the formation of low resistive CoSi2phase is delayed to about 660°C, as compared to conventional Co/Si system. Moreover, the presence of Ta in Co-Ta alloy films reduces the silicidation reaction rate, resulting in the strong preferential orientation in CoSi2 films. Upon high temperature post annealing in the furnace, the sheet resistance of Co-silicide formed from Co/Si systems increases significantly, while that of Co-Ta/Si systems maintains low. This is due to the formation of TaSi2 at the grain boundaries and surface of Co-silicide films, which prevents the grain boundary migration thereby slowing the agglomeration. Therefore, from our research, increased thermal stability of Co-silicide films was successfully obtained from Co-Ta alloy process.

Fluorescent dyes including Nile Red (NR), fluorescein, rhodamine and 4- (dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran (DCM) derivatives were investigated to find an application for the organic light emitting device (OLED). Relationship between the molecular structure and optical property was calculated by ab initio (HF and DFT/6-31G*) and semiempirical (AM1/PM3 and INDO/S) calculation methods for the geometry optimization and for the information of electronic transition, respectively. The absorption maximum and the oscillator strength of molecules strongly depended on the molecular dipole moment, especially for the molecules having both strong electron donor and acceptor group. Since the calculated results were comparable with several experimental results, these semiempirical molecular orbital calculation methods could be used as a powerful prediction tool for optical properties of the luminescent molecules.

We investigated the photoluminescence as well as the crystal structure and optical energy gaps of the Zn1-xCdxAl2Se4-4xS4x solid solution system based on the Al-related compounds of ZnAl2Se4, ZnAl2S4, CdAl2Se4, and CdAl2S4. The single crystals of the system with 0.0 ≤ x ≤ 1.0 were grown by the chemical transport reaction technique. The Zn1-xCdxAl2Se4-4xS4x crystallizes in a defect chalcopyrite structure for a whole composition and has an optical energy gap ranging from 3.525 to 3.577 eV at 13 K. The photoluminescence spectra at 13 K showed a strong emission band in the blue spectral region and a weak broad emission band in the visible region due to donor–acceptor pair recombination. The composition and temperature dependence of these bands were examined in the investigated regions. The simple energy band scheme for the radiative mechanisms of the Zn1-xCdxAl2Se4-4xS4x is proposed on the basis of our experimental results along with photo-induced current transient spectroscopy measurements.

The effect of varying the Si layer thickness on the Er3+ photoluminescence properties of Er-doped Si/SiO2 superlattice is investigated. We find that as the Si layer thickness is reduced from 3.6 nm down to a monolayer of Si, the Er3+ luminescence intensity increases by over an order of magnitude. Temperature dependence of the Er3+ luminescence intensity and time-resolved measurement of Er3+ luminescence intensity identify the increase in the excitation rate as the likely cause for such an increase, and underscore the importance of the Si/SiO2 interface in determining the Er3+ luminescence properties.