Floating body effect in indium-gallium-zinc-oxide (IGZO) thin-film transistor (TFT).

In this paper, the floating body effect (FBE) in indium-gallium-zinc-oxide (IGZO) thin-film transistor (TFT) and the mechanism of device failure caused by that are reported for the first time. If the toggle AC pulses are applied to the gate and drain simultaneously for the switching operation, the drain current of IGZO TFT increases dramatically and cannot show the on/off switching characteristics. This phenomenon was not reported before, and our study reveals that the main cause is the formation of a conductive path between the source and drain: short failure.

Lifetime estimation of thin-film transistors in organic emitting diode display panels with compensation.

Oxide semiconductor thin-film transistors (TFTs) are used in the pixel array and gate driver circuits of organic light emitting diode (OLED) display panels. Long-term reliability characteristics of the TFTs are a barometer of the lifetime of OLED display panels. The long-term reliability of the driver TFTs is evaluated in a short time under high voltages and high temperature for an accelerated degradation test.

Effects of multiple scattering on angle-independent structural color in disordered colloidal materials.

Disordered packings of colloidal spheres show angle-independent structural color when the particles are on the scale of the wavelength of visible light. Previous work has shown that the positions of the peaks in the reflectance spectra can be predicted accurately from a single-scattering model that accounts for the effective refractive index of the material. This agreement shows that the main color peak arises from short-range correlations between particles.

Photonic Microcapsules Containing Single-Crystal Colloidal Arrays with Optical Anisotropy.

Colloidal particles with a repulsive interparticle potential spontaneously form crystalline lattices, which are used as a motif for photonic materials. It is difficult to predict the crystal arrangement in spherical volume as lattices are incompatible with a spherical surface. Here, the optimum arrangement of charged colloids is experimentally investigated by encapsulating them in double-emulsion drops.

Photonic Capsule Sensors with Built-In Colloidal Crystallites.

Technologies to monitor microenvironmental conditions and its spatial distribution are in high demand, yet remain unmet need. Herein, photonic microsensors are designed in a capsule format that can be injected, suspended, and implanted in any target volume. Colorimetric sensors are loaded in the core of microcapsules by assembling core-shell colloids into crystallites through the depletion attraction.

Absence of red structural color in photonic glasses, bird feathers, and certain beetles.

Colloidal glasses, bird feathers, and beetle scales can all show structural colors arising from short-ranged spatial correlations between scattering centers. Unlike the structural colors arising from Bragg diffraction in ordered materials like opals, the colors of these photonic glasses are independent of orientation, owing to their disordered, isotropic microstructures. However, there are few examples of photonic glasses with angle-independent red colors in nature, and colloidal glasses with particle sizes chosen to yield structural colors in the red show weak color saturation.

Full-spectrum photonic pigments with non-iridescent structural colors through colloidal assembly.

Structurally colored materials could potentially replace dyes and pigments in many applications, but it is challenging to fabricate structural colors that mimic the appearance of absorbing pigments. We demonstrate the microfluidic fabrication of "photonic pigments" consisting of microcapsules containing dense amorphous packings of core-shell colloidal particles. These microcapsules show non-iridescent structural colors that are independent of viewing angle, a critical requirement for applications such as displays or coatings.

Osmotic-pressure-controlled concentration of colloidal particles in thin-shelled capsules.

Colloidal crystals are promising structures for photonic applications requiring dynamic control over optical properties. However, for ease of processing and reconfigurability, the crystals should be encapsulated to form 'ink' capsules rather than confined in a thin film. Here we demonstrate a class of encapsulated colloidal photonic structures whose optical properties can be controlled through osmotic pressure.

Two-dimensional directed assembly of dicolloids.

The assembly of ordered dicolloid monolayers is directed by an electric field. The dicolloid particles are polystyrene latex with a maximum equatorial diameter 3.45 μm and length 4.

The effects of radio frequency plasma power on Ai2O3 films deposited at room-temperature by remote plasma atomic layer deposition.

Al2O3 films were deposited by a remote plasma atomic layer deposition (RPALD) method at room temperature (25 degrees C) in a reactor using alternating exposures of Al(CH3)3 and O2 plasma. Oxygen plasma was used as a reactant gas to decompose the trimethylaluminum [TMA, Al(CH3)3] precursor at room temperature. The RF plasma power was increased to produce enough radicals for the deposition of the Al2O3 films at room temperature.

Assembly of optical-scale dumbbells into dense photonic crystals.

We describe the self-assembly of nonspherical particles into crystals with novel structure and optical properties combining a partial photonic band gap with birefringence that can be modulated by an external field or quenched by solvent evaporation. Specifically, we study symmetric optical-scale polymer dumbbells with an aspect ratio of 1.58.

High-yield synthesis of monodisperse dumbbell-shaped polymer nanoparticles.

We describe a method for producing highly monodisperse dumbbell-shaped polymer nanoparticles with dimensions on the order of a few hundred nanometers in extremely high yields. Our technique is based on seeded polymerization, where suspended core-shell particles (linear polystyrene core with polystyrene-co-trimethoxysilylpropylacrylate shell) are used as seeds. When an aqueous suspension of seed particles is mixed with monomer solution, the core-shell particles display dramatic changes in their morphology.

Cell stimulation with optically manipulated microsources.

Molecular gradients are important for various biological processes including the polarization of tissues and cells during embryogenesis and chemotaxis. Investigations of these phenomena require control over the chemical microenvironment of cells. We present a technique to set up molecular concentration patterns that are chemically, spatially and temporally flexible.

Synthesis of colloidal particles with the symmetry of water molecules.

We describe a method for synthesizing "colloidal water": monodisperse micrometer-sized polymer particles with the symmetry of water molecules. Our approach is based on multistep seeded polymerization with variation of cross-linker concentration in each step. This enables precise control of swelling selectivity and phase-separation, which control the particle morphology.

Anti-complementary activity of triterpenoides from fruits of Zizyphus jujuba.

In order to determine on the anti-complement activity of triterpenes, following eleven triterpenoides were isolated from the fruits of the Zizyphus jujuba MILL: ceanothane-type triterpenes: colubrinic acid (1), zizyberenalic acid (11); lupane-type triterpenes: alphitolic acid (2), 3-O-cis-p-coumaroyl alphitolic acid (3), 3-O-trans-p-coumaroyl alphitolic acid (4), betulinic acid (7), betulonic acid (9); and oleanane-type triterpenes: 3-O-cis-p-coumaroyl maslinic acid (5), 3-O-trans-p-coumaroyl maslinic acid (6), oleanolic acid (8), oleanonic acid (10). These compounds were examined for their anti-complement activity against the classical pathway of the complement system. Among them, compounds 5, 6, and 8 exhibited significant anti-complement activity with IC(50) values of 101.