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The p-i-n organic light-emitting devices (OLEDs) with a low turn-on voltage and a high power efficiency were fabricated by organic p-type 1,4,5,8,9,11-hexaazatriphenylene hexacarbonitrile (HAT-CN) layer and organic n-type 4,4′, 4 ″ -methylidynetris (N,N-dimethylaniline) (LCV) materials. The lowest operating voltage of the electron-only devices with a 2.5-wt.% LCV-doped BPhen layer was 4.02 V. The highest values of the current density and the luminance of the p-i-n OLEDs were 429.8 mA/cm2 at 7.0 V and 10,950 cd/m2 at 6.8 V, respectively. The turn-on voltage and the power efficiency of the p-i-n OLEDs with a HAT-CN layer and a LCV-doped BPhen ETL were 2.46 V and 2.76 lm/W, respectively. The enhancement of the power efficiency and the decrease in the turn-on voltage of the p-i-n OLEDs were attributed to the improvement of the hole and electron injections due to the utilization of the p-type HAT-CN and the n-type LCV-doped BPhen layers.

A direct analytical method for high speed quantitative analysis of lipids in human blood plasma using on-line chip-type asymmetrical flow field-flow fractionation-electrospray ionization-tandem mass spectrometry (cAF4-ESI-MS/MS) with selected reaction monitoring (SRM) is described in this study. Utilizing a miniaturized cAF4 channel, high speed size separation of high density lipoproteins (HDL) and low density lipoproteins (LDL) from plasma samples can be accomplished at a microflow rate along with simultaneous desalting of lipoproteins, both of which are conducive to direct ESI of lipids in lipoproteins. This study demonstrates that the SRM method to monitor phospholipids during cAF4-ESI-MS/MS can be successfully applied to the quantitation of lipid molecules in plasma lipoproteins without the need of a separate lipid extraction process. For quantitation of lipids in HDL and LDL during cAF4-ESI-MS/MS runs, a protein standard (carbonic anhydrase, 29 kDa) was added to each plasma sample as an internal standard such that a peak intensity of y67(+5) ions, which are high abundant SRM product ions of CA, could be utilized to calculate the relative intensity of each lipid molecule. The developed method was applied to plasma samples from 10 patients with coronary artery disease (CAD) and 10 healthy control samples, and quantitative analysis of 39 lipid molecules including phosphatidylcholines, phosphatidylethanolamines, sphingomyelins, phosphatidylglycerols, and phosphatidylinositols, resulted in the selection of 13 PL species showing more than 2.5 fold difference in relative abundance (p

A new indolocabazole derivative possessing an extended aromatic core and solubilizing long aliphatic chains effectively self-assembles and crystallizes within the nanoscale channels to form single-crystal nanowires via a direct printing method from an ink solution. Single-crystal organic nanowire transistor arrays based on the π-extended indolocarbazole derivative exhibit an excellent hole mobility of 1.5 cm² V⁻¹ s⁻¹ and outstanding environmental stability.

paste wascoated on the FTO layer with a doctor-blade method, and thecoated films were baked at 150 °C for 30 min, followed bycalcination at 500 °C for 15 min.Stoichiometric amounts of aluminum tri-sec-butoxide(97%, Aldrich) were dissolved in 20 mL 2-propanol to obtainthe Al precursor solutions with different concentrations.Nanoporous TiO

In the present study, a solution-processed organic semiconductor based on indolocarbazole derivative (heptazole) is introduced as a p-type donor material for a bulk-heterojunction photovoltaic device. The heptazole has an optical band gap of 2.97 eV, and its highest occupied molecular orbital-lowest unoccupied molecular orbital energy levels are compactable with the PC60BM to construct a donor-acceptor heterojuction for energy harvesting and transfer. When the bulk-heterojunction photovoltaic devices consisting of ITO/PEDOT:PSS/heptazole:PC60BM/Al with different blending ratio of heptazole:PC60BM were constructed, the cell with 1:1 blending ratio exhibited the best power conversion efficiency. Further, when an indoline organic dye (D149) was introduced as an interfacial modifier to the above donor/acceptor bulk heterojunction, the device demonstrated an enhanced overall power conversion efficiency from 1.26% to 2.51% hence demonstrating enhancement by the factor of 100%. The device was further characterized using electronic absorption spectroscopy, photoluminescence spectroscopy, electrochemical impedance spectroscopy, and the photovoltage decay kinetics. These studies reveal that the enhanced power conversion efficiency of the device is due to the enhanced charge transfer with the complementary light absorption feature of the interfacial D149 dye molecules.

We report on fabrication of upright-standing SnO2 nanowalls aligned on FTO substrates by a facile wet chemical method at low temperature. These nanowalls are dual-photosensitized with CdS quantum dots and Z907 dye molecules in order to construct panchromatic dye-sensitized solar cells. We demonstrate that thin CdS quantum dot layer not only acts as a blocking layer preventing recombination of charge carriers, but also contributes as a light absorber. A 158% improvement in power conversion efficiency is observed, which is attributed to improved light absorption, reduced recombination and improved charge collection in presence of CdS quantum dot interlayer.

Chemical bath deposition is an attractive technique to form single- and multilayered metal oxide/chalcogenide films on electrode surfaces. However, the occurrence of desorption and/or ion-exchange reaction during subsequent chemical bath deposition has so far limited preparation of multilayered metal oxide/chalcogenide films. In this paper, we report a method to prevent desorption and ion-exchange reaction of metal oxide/chalcogenide on electrode surfaces using a polyelectrolyte multilayer during sequential chemical bath deposition. By controlling the ion permeability of the polyelectrolyte multilayer, Cu(2-x)Se film was successfully deposited on the CdS film. The Cu(2-x)Se/CdS film is confirmed by UV-vis absorption spectroscopy, scanning electron microscopy, energy dispersive X-ray analysis, and X-ray powder diffractometer. Furthermore, the Cu(2-x)Se/CdS films were investigated as photoinduced charge transfer devices which showed photocurrents of 0.22 mA/cm(2) under illumination (I = 100 mW/cm(2)).

Thin films of nanocrystalline CuInSe2 were prepared on glass substrates using chemical bath deposition in acidic medium at room temperature. Thickness of the chemically deposited CuInSe2 thin films was approximately 100 nm which composed of closely packed irregular grains of approximately 100-120 nm in diameter. X-ray diffraction pattern of CuInSe2 thin films showed nanocrystalline structure with (112) preferential orientation. The films exhibited faint black and direct band gap energy was 0.96 eV.

A thin film of iodine doped polythiophene was grown photoelectrochemically around the dye-sensitized TiO(2) nanoparticles in a Grätzel cell, and the effect of iodine doping level on the cell performance was investigated using X-ray photoelectron spectroscopy, electrochemical impedance spectroscopy, and photovoltage decay. At an optimum doping level, the cell demonstrated the enhanced energy conversion efficiency by 27.52% compared to the cell without polythiophene.

When smart phones are now commonly distributed, the web accessibility through a mobile has invigorated. Not just because of smart phones, but because so many devices with various resolutions are available in the market, information cannot be correctly displayed on the web of the previous PC and an appropriate web matching with each resolution should be presented. This thesis will suggest a responsive web design optimized to correctly deliver the same information on all devices by changing a layout according to each resolution by using a single source through a media query. This is expected to raise the effect of advertisement by attracting attention of the public with a simple and comfortable design.

Anodization of alloys containing Al, Ni, Co and Fe as main constituents is reported here for the first time for formation of thin film of self-organized magnetic nanoporous structure. Fluoride concentration, anodization potential and the amount of water in the ethylene glycol electrolyte are very critical parameters to produce the well-aligned nanostructure. Further, the presence of Al in the alloy to protect the ferrite nanostructure by controlling the selective dissolution of oxide layers of Ni, Co, Cu was essential.

PbS quantum dot-sensitized solar cells (QDSCs) with a photovoltaic conversion efficiency (η) of 5.73% have been fabricated by applying Au/CuS/FTO as a counter electrode (CE), post-annealing the deposited PbS QDs, and introducing the bilayered TiO2 nanostructure as a photoanode.

Thin films of nanocrystalline CuInSe2 were prepared on glass substrates using chemical bath deposition in acidic medium at room temperature. Thickness of the chemically deposited CuInSe2 thin films was approximately 100 nm which composed of closely packed irregular grains of approximately 100-120 nm in diameter. X-ray diffraction pattern of CuInSe2 thin films showed nanocrystalline structure with (112) preferential orientation. The films exhibited faint black and direct band gap energy was 0.96 eV.

ZnO nanoparticles (NPs) coated with amorphous and crystalline CdS quantum dots (QDs) were successfully synthesized through chemical bath deposition (CBD) process. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) have been utilized to characterize the samples morphology and structural properties. The conduction band of CdS QDs is much higher than the ZnO conduction band facilitates electron transfer process through cascade system. The thickness and crystallinity of the CdS QDs coated on ZnO NPs critically controls the electron diffusion length and photovoltaic performance of the solar cell. The red shift from 506 to 524 nm, increased optical absorption in the UV-visible range and electron diffusion length limited by the thickness of the amorphous/crystalline CdS QDs coated on ZnO NPs film, influences the performance of the QDs sensitized solar cell (QDSSCs) under one sun illumination intensity (AM 1.5, 100 mW/cm2). The results discuss the CBD process controlled growth of CdS QDs on ZnO NPs and its influence on the photovoltaic performance of QDSSCs.

The present work demonstrates a facile, low cost and environmentally friendly technique for carburization of TiO2 nanotubes. XRD and XPS investigations suggest that the anodically grown self-organized TiO2 nanotubes when annealed in an argon filled steel nut–bolt cavity working as an autogenic pressure reactor undergo carburization at 650 °C, which converts TiO2 into TiOyCz. TEM-SAED suggests that the carburized nanotubes are polycrystalline, and also contain some reduced oxides of titanium. The conductivity measurement of the carburized nanotubes shows their conductivity to be close to metals. The electrochemical investigation of the carburized nanotubes demonstrates that the material can be used as a conductive electrode material for electrochemical reactions.

We report on the synthesis of CdO–CdSe nanoporous architectures from porous CdO architectures by a controlled solution anion exchange method. Monolithic CdCO3 micron sized crystals synthesized in the first step were decomposed by calcination to evolve CO2 to form porous CdO crystals, having a similar outer shape but with a tailored internal nanostructure. Controlled Se2− ion exchange with CdO crystals yielded CdO–CdSe architectures with tunable composition and optoelectronic properties. Pearson's acid–base concept is used as a guiding principle for controlling the morphology and composition of the formed architectures. The photoelectrochemical properties of the system comprising CdO–CdSe architectures were investigated at various stages of ion exchange intervals. CdO–CdSe architectures on indium tin oxide (ITO) is a promising photoelectrode with excellent photovoltaic properties exhibiting a short-circuit current density of 7.36 mA cm−2 under 1 Sun illumination.

Uniform and well-defined nanopopcorns of the tetragonal anatase TiO2 having an average diameter of 670 nm have been facilely grown on Ti foil via a hydrothermal method and characterized by analyzing electron microscopic images and electron diffraction patterns as well as X-ray photoelectron, photoluminescence, and Raman spectra. The morphology of TiO2 nanostructures on Ti foil has been controlled well by adjusting the volume ratio of H2O2 : HF : H2O, VR(H2O2 : HF : H2O). Truncated tetragonal pyramidal TiO2 nanocrystals exposing the {001} and {101} facets have grown on the surface of TiO2 nanostructures exposing the {001} facets to produce anatase TiO2 nanopopcorns. Without being treated via any annealing process, our well-defined TiO2 nanopopcorns on Ti foil have been directly employed for photocatalytic materials and dye-sensitized solar cells. Among our prepared samples, anatase TiO2 nanopopcorns grown on Ti foil at a VR(H2O2 : HF : H2O) of 1 : 1 : 1000 have shown the most reduced oxygen vacancy luminescence, the highest photocatalytic activity for the degradation of methylene blue, and the highest photovoltaic conversion efficiency of 3.98% as the working electrode of a dye-sensitized solar cell.

Self-organized nanoporous tin oxide films were fabricated by anodizing a tin substrate in an aqueous electrolyte containing oxalic or phosphoric acid. The films were characterized using FE-SEM, XRD, XPS, and TGA. In addition, the supercapacitive properties of the porous oxide films were measured using cyclic voltammetry and galvanostatic charge/discharge technique. The film demonstrated a maximum specific capacitance of 274 F g−1 with long life in electrochemical charge/discharge cycles.