Narrow Results

Crystalline zinc oxide (ZnO) particles with different morphologies have been synthesized by the hydrothermal method under the magnetic field. It is found that the magnetic field influences the nucleation and growth of ZnO crystals. ZnO crystals obtained under high pulsed magnetic field were more uniform and well integrated.

In this study, in order to obtain the optimal fabricating condition, the influences of heating temperature and time on the fabrication of zinc oxide (ZnO) nanowires are clarified. During this process, the synthesis and scanning electron microscope (SEM) images of ZnO nanostructures, produced by direct heating of metallic zinc, are presented. Besides, the SEM images and X-ray diffraction (XRD) patterns of products under different conditions are compared to analyze the surface morphology and composition of products. In the final observation, the best diameters of ZnO nanowires are achieved as 60–70 nm, which can be successfully applied as a substrate in Raman measurement. The optimal temperature is 450${}^{\circ }$C, as well as the optimal time is 40–50 min.

Novel composites of zinc oxide (ZnO) and copper phthalocyanines (CuTriPc and CuPc) were synthesized as efficient natural solar light photocatalysts for the photodegradation of organic wastewater pollutants. Spectroscopic and analytical measurements confirmed that both bulky triazolo copper phthalocyanine (CuTriPc) and unsubstituted planer (CuPc) were successfully coupled with ZnO nanoparticles. The synthesized nanocomposites were investigated as natural solar radiation photocatalysts toward the photodegradation of methylene blue (MB) analogue dye. The prepared CuTriPc/ZnO nanocomposite was proven to be an efficient solar light photocatalyst compared to pure ZnO and the unsubstituted CuPc/ZnO.

ZnO has been extensively used as oxide in the thin film electronics industry because of its performance advantages such as electrical and optical properties. This study represents the design and optimization of the ZnO thin film transistor (TFT). The characteristics of the device are studied using the software Silvaco TCAD ATLAS. The improvement in the performance of the device has been observed in optimizing dielectric layer thickness ($T_{\mathrm{\text{ox}}}$). Further SiO₂ oxide layer is replaced with the high-$k$ dielectric to improve its performance. The use of high-$k$ dielectric gives the concept of equivalent oxide thickness (EOT) in which physical thickness (PT) of the dielectric layer is increased without increasing electric thickness (effective thickness), which improves the reliability of the device. The electrical parameters extracted for the low-$k$ SiO2 ($K=3.9$) at thickness (TSiO2) 50nm are $I_{\mathrm{\text{on}}}=2.13\times 10^{-5}$A, $I_{\mathrm{\text{off}}}=1.41\times 10^{-12}$A, $I_{\mathrm{\text{on}}}∕I_{\mathrm{\text{off}}}=10^7$, $\mathrm{\text{SS}}=0.077$V/decade, $\mathrm{\text{VTH}}=0.27$V. The high performance of the device has been achieved using Al₂O₃ and HfO₂ as the dielectric material.

This paper reports a novel design of a surface plasmon resonance (SPR) device that can be developed into a high-performance biosensor. The design utilizes wurtzite crystal structure semiconductor (zinc oxide, ZnO) layers to enhance the SPR signal quality and to improve the full width at half maximum (FWHM) of the SPR reflectivity curve. There exists a new mechanism when the excitation in the plasmon energy is in resonance with the ZnO band-gap (BG) energy transfer process. The excitation energy between Au and ZnO causes an interactive, coupled phenomenon with the ZnO BG (λ_BG = 360–430 nm, 3.1–3.4 eV) when it matches the ZnO–Au interface surface plasmon (400 nm). We have optimized the design of the ZnO and Au thin films thicknesses through analytical comparisons with conventional SPR structures. Upon exposure to ethanol, the ZnO–Au device showed a 2-times decrease in the FWHM and a 4.5-times larger shift in intensity interrogation. The ZnO–Au device exhibits a wider linearity range and very higher sensitivity. This characteristic of the ZnO–Au device is the basis for realizing accurate and specific biomolecular detection.