Isolation of p-hydroxycinnamaldehyde as an antibacterial substance from the saw fly, Acantholyda parki S.

AbstractWe purified an antibacterial substance from larvae of the saw fly, Acantholyda parki S., and identified its molecular structure as p-hydroxycinnamaldehyde. We then synthesized it by reduction of p-hydroxycinnamic acid. The antibacterial activity of the synthetic p-hydroxycinnamaldehyde was equal to that of the authentic substance. This molecule was found to have a broad antibacterial spectrum against not only Gram-negative, but also Gram-positive bacteria. Furthermore, it showed antifungal activity against Candida albicans. We suggest that this substance may play a role in the defense system of this insect. This is the first report of p-hydroxycinnamaldehyde of animal origin

Characteristics of Ni-Doped IZO Layers Grown on IZO Anode for Enhancing Hole Injection in OLEDs

The preparation and characteristics of a Ni-doped indium zinc oxide (NIZO) layer were investigated to enhance hole injection in organic light emitting diodes (OLEDs). A thin NIZO layer with a thickness of 5 nm was cosputtered onto an indium zinc oxide (IZO) anode using tilted Ni and IZO dual targets dc magnetron sputtering at room temperature in a pure Ar atmosphere. Using 3 W of Ni dc power, we can obtain a NIZO (5 nm)/IZO (135 nm) double-layer anode with a sheet resistance of 30.04 / and an optical transmittance of 83.8% at a wavelength of 550 nm. In addition, it was found that the work function of the NIZO layer was higher than that of a pure IZO anode due to the presence of a NiOx phase in the NIZO layer. An increase of Ni dc power above 7 W significantly degrades the electrical and optical properties in the NIZO layer. X-ray diffraction examination demonstrated that the NIZO layer consisted of an amorphous structure regardless of the Ni dc deposition power due to low substrate temperature. Furthermore, an OLED fabricated on the NIZO layer exhibited a higher current density, luminance, and efficiency due to improved hole injection by the high work function NIZO. These results indicate that the NIZO/IZO anode scheme is a promising anode material system for enhancing hole injection from the anode into the active layer of OLEDs.The authors acknowledge financial support from LG Displays, OLED Panel Development team

Optical and structural properties of Al-Doped CdZnO Thin Films with different Al concentrations

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Photoluminescence Properties of ZnO Disks Grown on Au Nano Thin Films Using Vapor Phase Transport

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Structural and Optical Properties of ZnO Nanostructures with Various Distance Condition by Vapor Phase Transport

ZnO structures were grown on Au-catalyzed Si substrate with various distances between the source and substrate ranging from 5 to 50 mm by the vapor phase transport at the growth temperature of 900 degrees celcius in argon/oxygen ambient. The structural and optical properties of the ZnO structures were investigated by field-emission scanning electron microscopy, X-ray diffraction and photoluminescence. The ZnO structures exhibited different morphologies, such as nanowires and submicron particles. Particularly, when the distance from the source was 5 mm, it was observed the ZnO nanowires with diameters in the range of 70 to 250 nm and the narrowest full width at half maximum of X-ray diffraction and photoluminescence spectra with 0.061 degrees and 96 meV, respectively. Therefore, the ZnO nanowires had a high crystallinity and optical properties compared to the ZnO submicron particles.1101sciescopu

Emission wavelength tuning of porous silicon with ultra-thin ZnO capping layers by plasma-assisted molecular beam epitaxy

Porous silicon (PS) was prepared by electrochemical anodization. Ultra-thin zinc oxide (ZnO) capping layers were deposited on the PS by plasma-assisted molecular beam epitaxy (PA-MBE). The effects of the ZnO capping layers on the properties of the as-prepared PS were investigated using scanning electron microscopy (SEM) and photoluminescence (PL). The as-prepared PS has circular pores over the entire surface. Its structure is similar to a sponge where the quantum confinement effect (QCE) plays a fundamental role. It was found that the dominant red emission of the porous silicon was tuned to white light emission by simple deposition of the ultra-thin ZnO capping alyers. Specifically, the intensity of white light emission was observed to be enhanced by increasing the growth time from 1 to 3 min.1111sciescopu

Effects of Ga Doping on Structural and Optical Properties of ZnO Nanorods

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