Controlled synthesis and field emission properties of ZnO nanostructures with different morphologies

Luteolin-Fabricated ZnO Nanostructures Showed PLK-1 Mediated Anti-Breast Cancer Activity

The present work describes a facile and convenient procedure for synthesizing zinc oxide nanoparticles using luteolin isolated from Eclipta alba plant (L-ZnONPs) at room temperature. The formation of as-grown L-ZnONPs was confirmed by X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HR-TEM), and selected area electron diffraction (SAED). The Wurtzite structure of ZnO was observed by its hexagonal phases in diffraction patterns. The SEM images revealed the different sizes and morphologies of L-ZnONPs, with diameters between 12 and 25 nm. The HR-TEM result showed that the inter-planar distance between two lattice fringes was 0.262 nm, which coincides with the d-spacing of (002) and (101) lattice planes of the as-obtained material. The anticancer activity of L-ZnONPs against the breast cancer cell line MCF-7 was greater as compared to that of luteolin or ZnO alone. The mechanistic evaluation of such an activity carried out using in silico methods suggested that the anti-breast cancer activity of L-ZnONPs was mediated by polo-like kinase 1 (PLK1) proteins.

Acoustics and thermal studies of conventional heat transfer fluids mixed with ZnO nano flakes at different temperatures

The present investigation is mainly focused upon the effect of adding zinc oxide nano particles in the conventional heat transfer fluid involving the mixture of ethylene glycol & water (EG-water). Efforts have been made to synthesize zinc oxide nano particles by precipitation technique and to blend with EG-water to prepare nanofluids using ultrasonication. From the characterization, the shapes of the particles were found to be agglomerated nano flakes. The ultrasonic velocity and transport properties have been measured to characterize the nanofluids and they also shed light on the molecular environment of the dispersed phase at different temperatures. The dynamic viscosity shows the nanofluids to be non-Newtonian fluids at very less shear rate. In addition, the stability of the nanofluid is being interpreted from UV-visible study.

Dissolving behavior and electrical properties of ZnO wire in HCl solution

In this paper, the preferential etching plane and electrical properties of ZnO wires are investigated after reaction with HCl solution.

Piezotronic interface engineering on ZnO/Au-based Schottky junction for enhanced photoresponse of a flexible self-powered UV detector

Exploiting piezoelectric effect to engineer material interface has been confirmed as a promising way to optimize the performance of optoelectronic devices. Here, by using this effect, we have greatly improved the photoresponse of the fabricated ZnO/Au Schottky junction based self-powered UV detector. A 440% augment of photocurrent, together with 5× increased sensitivity, was obtained when the device was subjected to a 0.580% tensile strain. The enhancement can be attributed to the facility separation and extraction of photoexcites due to the formation of the stronger and expanding built-in field, which is a result of charge redistribution induced by piezoelectric polarization at the ZnO/Au interface. This study not only can strengthen the understanding of piezoelectric effects on energy devices but also can be extended to boost performances of optoelectronic devices made of piezoelectric semiconductor materials.

Self-powered UV photosensor based on PEDOT:PSS/ZnO micro/nanowire with strain-modulated photoresponse

Developing tailored micro/nanostructure interfaces is an effective way to make novel optoelectronic devices or enhance their performances. Here we report the fabrication of a PEDOT:PSS/ZnO micro/nanowire-based self-powered UV photosensor. The generation of photocurrent at zero bias is attributed to the separation of photogenerated electron-hole pairs within the built-in electric field at the PEDOT:PSS/ZnO interface upon UV light illumination. Furthermore, the piezotronic effect on the UV photoresponsivity under different strains is investigated, which is due to the modification of energy band diagram at the p-n heterojunction by strain-induced piezoelectric polarization. This study demonstrates a prospective approach to engineering the performance of a photodetector through straining and may offer theoretical supporting in future optoelectronic device fabrication and modification.

Synthesis and transverse electromechanical characterization of single crystalline ZnO nanoleaves

ZnO nanoleaves are synthesized by using a simple chemical vapor deposition method. The transverse electromechanical characterization of single nanoleaves was investigated and the results show that the current density increases with increasing loading forces, which was suggested to be attributed to the decrease of the Schottky barrier height (SBH).

Field-emission properties of individual ZnO nanowires studied in situ by transmission electron microscopy

The field-emission properties of individual zinc oxide (ZnO) nanowires, grown by a solid-vapour phase thermal evaporation process, were studied in situ by transmission electron microscopy (TEM) using a home-made piezo-manipulator. The results indicate that ZnO nanowires present an outstanding field-emission property with low turn-on voltage and high emission current; the proper linearity of 1/V-ln(I/V(2)) curves basically accords with the Fowler-Nordheim model, and the dependence of the field-enhancement factor β on the distance d between the nanowire tip and its counter anode fits a linear relationship. The investigations show that ZnO nanowires show promise for potential applications as field emitters.