Zinc Oxide Nanostructures: Synthesis and Characterization

The summary should be ca. 200 words; this text will present the book in all promotional forms (e.g. flyers). Please describe the book in straightforward and consumer-friendly terms. [Zinc oxide (ZnO) is a wide band gap semiconductor with an energy gap of 3.37 eV at room temperature. It has been used considerably for its catalytic, electrical, optoelectronic, and photochemical properties. ZnO nanomaterials, such as quantum dots, nanorods, and nanowires, have been intensively investigated for their important properties. Many methods have been described in the literature for the production of ZnO nanostructures, such as laser ablation, hydrothermal methods, electrochemical deposition, sol-gel methods, chemical vapour deposition, molecular beam epitaxy, the common thermal evaporation method, and the soft chemical solution method. The present Special Issue is devoted to the synthesis and characterization of ZnO nanostructures with novel technological applications.

Recent Developments in Ozone Sensor Technology for Medical Applications

There is increasing interest in the utilisation of medical gases, such as ozone, for the treatment of herniated disks, peripheral artery diseases, and chronic wounds, and for dentistry. Currently, the in situ measurement of the dissolved ozone concentration during the medical procedures in human bodily liquids and tissues is not possible. Further research is necessary to enable the integration of ozone sensors in medical and bioanalytical devices. In the present review, we report selected recent developments in ozone sensor technology (2016–2020). The sensors are subdivided into ozone gas sensors and dissolved ozone sensors. The focus thereby lies upon amperometric and impedimetric as well as optical measurement methods. The progress made in various areas—such as measurement temperature, measurement range, response time, and recovery time—is presented. As inkjet-printing is a new promising technology for embedding sensors in medical and bioanalytical devices, the present review includes a brief overview of the current approaches of inkjet-printed ozone sensors

Recent Advances in Thin Film Electronic Devices

This reprint is a collection of the papers from the Special Issue “Recent Advances in Thin Film Electronic Devices” in Micromachines. In this reprrint, 1 editorial and 11 original papers about recent advances in the research and development of thin film electronic devices are included. Specifically, three research fields are covered: device fundamentals (5 papers), fabrication processes (5 papers), and testing methods (1 paper). The experimental data, simulation results, and theoretical analysis presented in this reprint should benefit those researchers in flat panel displays, flat panel sensors, energy devices, memories, and so on

ZnO Quasi-1D Nanostructures: Synthesis, Modeling, and Properties for Applications in Conductometric Chemical Sensors

One-dimensional metal oxide nanostructures such as nanowires, nanorods, nanotubes, and nanobelts gained great attention for applications in sensing devices. ZnO is one of the most studied oxides for sensing applications due to its unique physical and chemical properties. In this paper, we provide a review of the recent research activities focused on the synthesis and sensing properties of pure, doped, and functionalized ZnO quasi-one dimensional nanostructures. We describe the development prospects in the preparation methods and modifications of the surface structure of ZnO, and discuss its sensing mechanism. Next, we analyze the sensing properties of ZnO quasi-one dimensional nanostructures, and summarize perspectives concerning future research on their synthesis and applications in conductometric sensing devices

Effect of Zinc Oxide Modification by Indium Oxide on Microstructure, Adsorbed Surface Species, and Sensitivity to CO

Additives in semiconductor metal oxides are commonly used to improve sensing behavior of gas sensors. Due to complicated effects of additives on the materials microstructure, adsorption sites and reactivity to target gases the sensing mechanism with modified metal oxides is a matter of thorough research. Herein, we establish the promoting effect of nanocrystalline zinc oxide modification by 1–7 at.% of indium on the sensitivity to CO gas due to improved nanostructure dispersion and concentration of active sites. The sensing materials were synthesized via an aqueous coprecipitation route. Materials composition, particle size and BET area were evaluated using X-ray diffraction, nitrogen adsorption isotherms, high-resolution electron microscopy techniques and EDX-mapping. Surface species of chemisorbed oxygen, OH-groups, and acid sites were characterized by probe molecule techniques and infrared spectroscopy. It was found that particle size of zinc oxide decreased and the BET area increased with the amount of indium oxide. The additive was observed as amorphous indium oxide segregated on agglomerated ZnO nanocrystals. The measured concentration of surface species was higher on In2O3-modified zinc oxide. With the increase of indium oxide content, the sensor response of ZnO/In2O3 to CO was improved. Using in situ infrared spectroscopy, it was shown that oxidation of CO molecules was enhanced on the modified zinc oxide surface. The effect of modifier was attributed to promotion of surface OH-groups and enhancement of CO oxidation on the segregated indium ions, as suggested by DFT in previous work

Innovative ozone sensors for environmental monitoring working at low temperature

L'abstract è presente nell'allegato / the abstract is in the attachmen

Device Fabrication and Characterization for Biological and Radiation Sensing

Amorphous indium gallium zinc oxide (IGZO) thin film transistors (TFT) has revolutionized the display industry enabling smaller pixel sizes and higher refreshing rates than traditional amorphous Si: H TFTs. These attributes of IGZO were leveraged to make a field-effect sensing (FES) platform capable of sensing various biomarkers. The sensitivity and selectivity of the sensor to glucose was achieved by functionalizing the IGZO back channel surface with aminosilane groups which were further cross-linked with glucose oxidase (GOx) enzymes. The sensor was integrated with a microfluidic channel, and the sensor response was studied with respect to varying glucose concentrations. An analysis of the sensitivity of the sensor for various gate voltages (VG) was conducted to determine the optimal VG to operate the sensor for continuous glucose sensing. These sensing platforms can be made completely transparent and are compatible for integration onto flexible substrates enabling transparent active-matrix sensing arrays (TASA) where multiple biomarkers can be sensed which will aid next-generation internet of things (IoT) hardware for human health monitoring and analytics. Lead selenide (PbSe) nanocrystalline (NC) particles have a large Bohr radius (~ 46 nm) which enables high quantum confinement effects in relatively larger diameter NC PbSe. As a consequence, the efficiency of charge multiplication (CM) on impact ionization (II) is enhanced for NC compared to bulk PbSe. In addition, a relatively high density of these NC PbSe enables complete transfer of high energy radiation in a relatively thin sensing layer. However, the radiation sensing capability and electronic transport for NC PbSe radiation detectors is impeded by long-chain stabilizing organic ligands on the NC surface as well as the current fabrication methods. In this research, a biphasic ligand exchange process was integrated to the detector fabrication protocol to improve electrical conductivity by reducing interparticle distance and improved packing efficiency. In addition, the fabrication complexity of the radiation sensors was greatly reduced due to solution based ligand exchange, which can be scalable in achieving thick, crack free NC PbSe films. Improved conductivity and Schottky like behavior, which are desirable for good radiation sensing, were demonstrated in the fabricated NC PbSe radiation detector