Journal articles: 'Nanostructured Oxide Semiconductors'

1

Sun, Peng. "Gas Sensors Based on Oxide Semiconductors with Porous Nanostructures." Proceedings 14, no. 1 (June 19, 2019): 13. http://dx.doi.org/10.3390/proceedings2019014013.

Full text

Abstract:

Gas sensor as a device composed of sensing material coupled with signal transducer, has been acknowledged as an analytical tool for detection and quantification of inflammable, explosive or toxic gases. The gas sensors based on nanostructured oxide semiconductor endowed with excellent sensing properties have exhibited great potential application in the fields of environmental monitoring, resource exploration, medical welfare, etc. It is well known that the sensing mechanism of sensor employing oxide semiconductors is mainly that the interactions between the surface adsorbed oxygen species and target gases lead to a change in the electrical conductivity. Therefore, the gas sensing properties of oxide semiconductors are closely related with their composition, crystalline size, and microstructure. In this regard, design and preparation of oxides with novel architectures will be increasingly important in the construction of high performance gas sensors. Due to high specific surface area, low density, and good surface permeability, porous nanostructures oxide semiconductor sensing materials have attracted growing interest in recent years. In our work, we successfully prepared various porous nanostructures oxides and their composites to the construction of high performances gas sensors with enhanced sensitivity, selectivity, as well as lowered detection limit. The subsequent gas sensing measurements explicitly revealed that these oxides and composites manifested superior sensing behaviors (like much higher sensitivity and faster response speed), which can be ascribed to the porous architectures and the synergistic effects.

APA, Harvard, Vancouver, ISO, and other styles

2

Díaz, Carlos, Marjorie Segovia, and Maria Luisa Valenzuela. "Solid State Nanostructured Metal Oxides as Photocatalysts and Their Application in Pollutant Degradation: A Review." Photochem 2, no. 3 (August 5, 2022): 609–27. http://dx.doi.org/10.3390/photochem2030041.

Full text

Abstract:

Most dyes used in various industries are toxic and carcinogenic, thus posing a serious hazard to humans as well as to the marine ecosystem. Therefore, the impact of dyes released into the environment has been studied extensively in the last few years. Heterogeneous photocatalysis has proved to be an efficient tool for degrading both atmospheric and aquatic organic contaminants. It uses the sunlight in the presence of a semiconductor photocatalyst to accelerate the remediation of environmental contaminants and the destruction of highly toxic molecules. To date, photocatalysis has been considered one of the most appealing options for wastewater treatment due to its great potential and high efficiency by using sunlight to remove organic pollutants and harmful bacteria with the aid of a solid photocatalyst. Among the photocatalysts currently used, nanostructured metal oxide semiconductors have been among the most effective. This review paper presents an overview of the recent research improvements on the degradation of dyes by using nanostructured metal oxide semiconductors obtained by a solid-state method. Metal oxides obtained by this method exhibited better photocatalytic efficiency than nanostructured metal oxides obtained using other solution methods in several cases. The present review discusses examples of various nanostructured transition metal oxides—such as TiO2, Fe2O3, NiO, ReO3, IrO2, Rh2O3, Rh/RhO2, and the actinide ThO2—used as photocatalysts on methylene blue. It was found that photocatalytic efficiency depends not only on the bandgap of the metal oxide but also on its morphology. Porous nanostructured metal oxides tend to present higher photocatalytic efficiency than metal oxides with a similar band gap.

APA, Harvard, Vancouver, ISO, and other styles

3

John Chelliah, Cyril R. A., and Rajesh Swaminathan. "Current trends in changing the channel in MOSFETs by III–V semiconducting nanostructures." Nanotechnology Reviews 6, no. 6 (November 27, 2017): 613–23. http://dx.doi.org/10.1515/ntrev-2017-0155.

Full text

Abstract:

AbstractThe quest for high device density in advanced technology nodes makes strain engineering increasingly difficult in the last few decades. The mechanical strain and performance gain has also started to diminish due to aggressive transistor pitch scaling. In order to continue Moore’s law of scaling, it is necessary to find an effective way to enhance carrier transport in scaled dimensions. In this regard, the use of alternative nanomaterials that have superior transport properties for metal-oxide-semiconductor field-effect transistor (MOSFET) channel would be advantageous. Because of the extraordinary electron transport properties of certain III–V compound semiconductors, III–Vs are considered a promising candidate as a channel material for future channel metal-oxide-semiconductor transistors and complementary metal-oxide-semiconductor devices. In this review, the importance of the III–V semiconductor nanostructured channel in MOSFET is highlighted with a proposed III–V GaN nanostructured channel (thickness of 10 nm); Al2O3 dielectric gate oxide based MOSFET is reported with a very low threshold voltage of 0.1 V and faster switching of the device.

APA, Harvard, Vancouver, ISO, and other styles

4

Galoppini, Elena. "(Invited) Bridge Design for Photoactive Molecules at Interfaces." ECS Meeting Abstracts MA2018-01, no. 31 (April 13, 2018): 1849. http://dx.doi.org/10.1149/ma2018-01/31/1849.

Full text

Abstract:

Electron transfer at the interface between a photoactive molecule and large bandgap nanostructured metal oxide semiconductors (ZnO, TiO2 for instance) remains at the center of intense research in numerous areas of solar energy conversion. Such areas encompass photocatalysis and solar fuels, photovoltaics, energy storage, and artificial photosynthesis. An enduring challenge is the ability to achieve control of the chromophore/semiconductor interface at the molecular level. The goal of our collaborative research is to address it by a combination of synthetic design and interfacial charge transfer studies. The presentation will describe the development of “functional” linkers for chromophore-linker model compounds that are able to tune and control the energy level alignment of molecules on nanostructured or single crystal inorganic semiconductors.

APA, Harvard, Vancouver, ISO, and other styles

5

Limongelli, Julia, Felicia Tolea, Mihaela Valeanu, Lucian Diamandescu, Tianhong Xu, and Monica Sorescu. "Nanostructured iridium oxide-hematite magnetic ceramic semiconductors." Ceramics International 41, no. 1 (January 2015): 333–43. http://dx.doi.org/10.1016/j.ceramint.2014.08.076.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Anta, Juan A. "Electron transport in nanostructured metal-oxide semiconductors." Current Opinion in Colloid & Interface Science 17, no. 3 (June 2012): 124–31. http://dx.doi.org/10.1016/j.cocis.2012.02.003.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

McGehee, Michael D. "Nanostructured Organic–Inorganic Hybrid Solar Cells." MRS Bulletin 34, no. 2 (February 2009): 95–100. http://dx.doi.org/10.1557/mrs2009.27.

Full text

Abstract:

AbstractWhen light is absorbed in organic semiconductors, bound electron–hole pairs known as excitons are generated. The electrons and holes separate from each other at an interface between two semiconductors by electron transfer. It is advantageous to form well-ordered nanostructures so that all of the excitons can reach the interface between the two semiconductors and all of the charge carriers have a pathway to the appropriate electrode. This article discusses charge and exciton transport in organic semiconductors, as well as the opportunities for making highly efficient solar cells and for using carbon nanotubes to replace metal oxide electrodes.

APA, Harvard, Vancouver, ISO, and other styles

8

Dadkhah, Mehran, and Jean-Marc Tulliani. "Nanostructured Metal Oxide Semiconductors towards Greenhouse Gas Detection." Chemosensors 10, no. 2 (January 30, 2022): 57. http://dx.doi.org/10.3390/chemosensors10020057.

Full text

Abstract:

Climate change and global warming are two huge current threats due to continuous anthropogenic emissions of greenhouse gases (GHGs) in the Earth’s atmosphere. Accurate measurements and reliable quantifications of GHG emissions in air are thus of primary importance to the study of climate change and for taking mitigation actions. Therefore, the detection of GHGs should be the first step when trying to reduce their concentration in the environment. Throughout recent decades, nanostructured metal oxide semiconductors have been found to be reliable and accurate for the detection of many different toxic gases in air. Thus, the aim of this article is to present a comprehensive review of the development of various metal oxide semiconductors, as well as to discuss their strong and weak points for GHG detection.

APA, Harvard, Vancouver, ISO, and other styles

9

Rud, Vasily, Doulbay Melebaev, Viktor Krasnoshchekov, Ilya Ilyin, Eugeny Terukov, Maksim Diuldin, Alexey Andreev, Maral Shamuhammedowa, and Vadim Davydov. "Photosensitivity of Nanostructured Schottky Barriers Based on GaP for Solar Energy Applications." Energies 16, no. 5 (February 28, 2023): 2319. http://dx.doi.org/10.3390/en16052319.

Full text

Abstract:

This work investigates the surface-barrier photoelectric properties of Au-palladium-n-GaP structures. Research into the visible spectrum region, under the action of both linearly polarized and natural radiation, provides us with new information about the height of the barrier, the interface m-s section, and the GaP band structure. SBs based on GaP (p- and n-type) are helpful for researchers in developing advantageous structures for creating various photovoltaic devices—photodetectors for fiber-optic control of energy systems or possible structures for solar energy. Despite many years of research, issues concerning the band structure of semiconductors based on the phenomenon of photoelectroactive absorption in such surface-barrier structures’ m-s remain urgent in the creation of new high-performance devices. Such structures may also be interesting for creating solar energy systems. They create a thin insulating dielectric layer (usually an oxide layer) in solar cells on SBs between the m and the semiconductor substrate. The advantage of solar cells based on m dielectric semiconductor structures is the strong electric field near the surface of the semiconductor that usually has a direction favoring the collection of carriers created by short-wavelength light. Diffusion of impurities usually results in crystal defects in the active region. There are no such defects in the studied elements. This is also the difference between solar cells on m dielectric structures and elements with diffusion in p-n junctions. We studied the PS of Au-Pd-n-GaP nanostructures to determine the height of the potential barrier qφBo and obtained accurate data on the zone structure of the n-GaP. The PS of nanostructured Au-Pd-n-GaP structures was studied in the visible region of the spectrum. Essential information about the semiconductor’s potential barrier parameters and band structure was obtained. The intermediate Pd nanolayer between Au and GaP has specific effects on the Au-Pd-n-GaP nanostructure, which are of considerable practical and scientific significance for future needs.

APA, Harvard, Vancouver, ISO, and other styles

10

Bhaumik, Anagh, Austin M. Shearin, Rishi Patel, and Kartik Ghosh. "Significant enhancement of optical absorption through nano-structuring of copper based oxide semiconductors: possible future materials for solar energy applications." Phys. Chem. Chem. Phys. 16, no. 22 (2014): 11054–66. http://dx.doi.org/10.1039/c4cp00827h.

Full text

APA, Harvard, Vancouver, ISO, and other styles

11

Lu, Yuzheng, Youquan Mi, Junjiao Li, Fenghua Qi, Senlin Yan, and Wenjing Dong. "Recent Progress in Semiconductor-Ionic Conductor Nanomaterial as a Membrane for Low-Temperature Solid Oxide Fuel Cells." Nanomaterials 11, no. 9 (September 3, 2021): 2290. http://dx.doi.org/10.3390/nano11092290.

Full text

Abstract:

Reducing the operating temperature of Solid Oxide Fuel Cells (SOFCs) to 300–600 °C is a great challenge for the development of SOFC. Among the extensive research and development (R&D) efforts that have been done on lowering the operating temperature of SOFCs, nanomaterials have played a critical role in improving ion transportation in electrolytes and facilitating electrochemical catalyzation of the electrodes. This work reviews recent progress in lowering the temperature of SOFCs by using semiconductor-ionic conductor nanomaterial, which is typically a composition of semiconductor and ionic conductor, as a membrane. The historical development, as well as the working mechanism of semiconductor-ionic membrane fuel cell (SIMFC), is discussed. Besides, the development in the application of nanostructured pure ionic conductors, semiconductors, and nanocomposites of semiconductors and ionic conductors as the membrane is highlighted. The method of using nano-structured semiconductor-ionic conductors as a membrane has been proved to successfully exhibit a significant enhancement in the ionic conductivity and power density of SOFCs at low temperatures and provides a new way to develop low-temperature SOFCs.

APA, Harvard, Vancouver, ISO, and other styles

12

Rabatic, Bryan M., Martin U. Pralle, Gregory N. Tew, and Samuel I. Stupp. "Nanostructured Semiconductors Templated by Cholesteryl-Oligo(Ethylene Oxide) Amphiphiles." Chemistry of Materials 15, no. 6 (March 2003): 1249–55. http://dx.doi.org/10.1021/cm020899e.

Full text

APA, Harvard, Vancouver, ISO, and other styles

13

Kozyrev, Evgeny Nikolaevich, Igor Nikolaevich Goncharov, Tamerlan Taymurazovich Magkoev, Rovan Olegovich Askerov, and Dmitry Zurabovich Pizhelauri. "Solar Energy Converter into the Electric Energy Based on Perovskite." Nano Hybrids and Composites 28 (February 2020): 155–60. http://dx.doi.org/10.4028/www.scientific.net/nhc.28.155.

Full text

Abstract:

The paper discusses the methods for the formation of solar-to-electrical converters on perovskites. The possibility of using inorganic semiconductors as a transport layer is shown. The solar energy converter is formed on the basis of the nanostructured porous anodic aluminum oxide.

APA, Harvard, Vancouver, ISO, and other styles

14

Ogurcovs, Andrejs, Kevon Kadiwala, Eriks Sledevskis, Marina Krasovska, and Valdis Mizers. "Glyphosate Sensor Based on Nanostructured Water-Gated CuO Field-Effect Transistor." Sensors 22, no. 22 (November 12, 2022): 8744. http://dx.doi.org/10.3390/s22228744.

Full text

Abstract:

This research presents a comparative analysis of water-gated thin film transistors based on a copper oxide (CuO) semiconductor in the form of a smooth film and a nanostructured surface. A smooth CuO film was deposited through reactive magnetron sputtering followed by annealing in atmosphere at a temperature of 280 ∘C. Copper oxide nanostructures were obtained by hydrothermal synthesis on a preliminary magnetron sputtered 2 nm thick CuO precursor followed by annealing at 280 ∘C. An X-ray diffraction (XRD) analysis of the samples revealed the presence of a tenorite (CuO) phase with a predominant orientation of (002). Scanning electron microscopy (SEM) and atomic force microscopy (AFM) studies of the samples revealed a highly developed surface with crystallites having a monoclinic syngony and dimensions of 15–20 nm in thickness, 150 nm in length, and 100 nm in height relative to a 2.5 nm height for the CuO crystallites of the smooth film. Electric measurements of the studied devices revealed typical current–voltage characteristics of semiconductors with predominant hole conductivity. The maximum ON/OFF ratio at a rain-source voltage of 0.4 volts and −1.2 volts on the gate for a smooth film was 102, and for a nanostructured transistor, it was 103. However, a much stronger saturation of the channel was observed for the nanostructured channel than for the smooth film. A test solution containing glyphosate dissolved in deionized water in three different concentrations of 5, 10, and 15 μmol/L was used during the experiments. The principle of operation was based on the preliminary saturation of the solution with Cu ions, followed by the formation of a metal–organic complex alongside glyphate. The glyphosate contents in the analyte led to a decrease in the conductivity of the transistor on the axis of the smooth film. In turn, the opposite effect was observed on the nanostructured surface, i.e., an increase in conductivity was noted upon the introduction of an analyte. Despite this, the overall sensitivity of the nanostructured device was twice as high as that of the device with a thin film channel. The relative changes in the field-effect transistor (FET) conductivity at maximum glyphosate concentrations of 15 μmol/L reached 19.42% for the nanostructured CuO film and 3.3% for the smooth film.

APA, Harvard, Vancouver, ISO, and other styles

15

Sendi, Aymen, Philippe Menini, Myrtil L. Kahn, Katia Fajerwerg, and Pierre Fau. "Effect of Nanostructured Octahedral SnO2 Added with a Binary Mixture P-Type and N-Type Metal Oxide on CO Detection." Proceedings 2, no. 13 (December 3, 2018): 986. http://dx.doi.org/10.3390/proceedings2130986.

Full text

Abstract:

In this work, we study the effect of nanostructured octahedral SnO2 added with a binary mixture p-type and n-type metal oxide semiconductors of CuO and ZnO, on CO detection at two concentrations (100 ppm and 1000 ppm). These metal oxides (SnO2 and binary mixture of CuO75%/ZnO25%) are prepared in the form of a serigraphy paste and deposited on an optimized silicon micro-hotplate. The sensors can be operated at temperature of 550 °C with a low energy consumption of only 55 mW. The binary and ternary mixtures of metal oxide are operated at different working temperature to optimize their sensitivity to CO.

APA, Harvard, Vancouver, ISO, and other styles

16

Haviar, Stanislav, Nirmal Kumar, Šárka Batková, and Jiří Čapek. "Nanostructured Materials Based on Thin Films and Nanoclusters for Hydrogen Gas Sensing." Proceedings 56, no. 1 (January 5, 2021): 38. http://dx.doi.org/10.3390/proceedings2020056038.

Full text

Abstract:

In this paper, we present two approaches to synthesize nanostructured metal oxide semiconductors in a form of multi-layer thin films later assembled as a conductometric gas-sensors. The first approach produces a combination of thin solid film of tungsten trioxide (WO3) with nanoclusters of cupric oxide (CuO) prepared by a magnetron-based gas aggregation cluster source (GAS). The second method is a two-step reactive magnetron sputtering forming a nanostructured copper tungstate (CuWO4) on-top of a WO3 film. Both methods lead to synthesis of nanosized hetero-junctions. These greatly improve the sensorial response to hydrogen in comparison with a WO3 thin film alone.

APA, Harvard, Vancouver, ISO, and other styles

17

Luciani, Giuseppina, Claudio Imparato, and Giuseppe Vitiello. "Photosensitive Hybrid Nanostructured Materials: The Big Challenges for Sunlight Capture." Catalysts 10, no. 1 (January 10, 2020): 103. http://dx.doi.org/10.3390/catal10010103.

Full text

Abstract:

Solar radiation is becoming increasingly appreciated because of its influence on living matter and the feasibility of its application for a variety of purposes. It is an available and everlasting natural source of energy, rapidly gaining ground as a supplement and alternative to the nonrenewable energy feedstock. Actually, an increasing interest is involved in the development of efficient materials as the core of photocatalytic and photothermal processes, allowing solar energy harvesting and conversion for many technological applications, including hydrogen production, CO2 reduction, pollutants degradation, as well as organic syntheses. Particularly, photosensitive nanostructured hybrid materials synthesized coupling inorganic semiconductors with organic compounds, and polymers or carbon-based materials are attracting ever-growing research attention since their peculiar properties overcome several limitations of photocatalytic semiconductors through different approaches, including dye or charge transfer complex sensitization and heterostructures formation. The aim of this review was to describe the most promising recent advances in the field of hybrid nanostructured materials for sunlight capture and solar energy exploitation by photocatalytic processes. Beside diverse materials based on metal oxide semiconductors, emerging photoactive systems, such as metal-organic frameworks (MOFs) and hybrid perovskites, were discussed. Finally, future research opportunities and challenges associated with the design and development of highly efficient and cost-effective photosensitive nanomaterials for technological claims were outlined.

APA, Harvard, Vancouver, ISO, and other styles

18

Zoolfakar, Ahmad Sabirin, Rozina Abdul Rani, Anthony J. Morfa, Anthony P. O'Mullane, and Kourosh Kalantar-zadeh. "Nanostructured copper oxide semiconductors: a perspective on materials, synthesis methods and applications." J. Mater. Chem. C 2, no. 27 (2014): 5247–70. http://dx.doi.org/10.1039/c4tc00345d.

Full text

APA, Harvard, Vancouver, ISO, and other styles

19

Fouad, O. A. "Formation of nanostructured tin oxide semiconductors by a simple thermal redox process." Crystal Research and Technology 41, no. 9 (September 2006): 880–84. http://dx.doi.org/10.1002/crat.200510687.

Full text

APA, Harvard, Vancouver, ISO, and other styles

20

Feng, Chengang, Mingdong Yi, Shunyang Yu, Ivo A. Hümmelgen, Tong Zhang, and Dongge Ma. "Hybrid Permeable Metal-Base Transistor with Large Common-Emitter Current Gain and Low Operational Voltage." Journal of Nanoscience and Nanotechnology 8, no. 4 (April 1, 2008): 2037–43. http://dx.doi.org/10.1166/jnn.2008.054.

Full text

Abstract:

We demonstrate the suitability of N,N′-diphenyl-N,N′-bis(1-naphthylphenyl)-1,1′-biphenyl-4,4′-diamine (NPB), an organic semiconductor widely used in organic light-emitting diodes (OLEDs), for high-gain, low operational voltage nanostructured vertical-architecture transistors, which operate as permeable-base transistors. By introducing vanadium oxide (V2O5) between the injecting metal and NPB layer at the transistor emitter, we reduced the emitter operational voltage. The addition of two Ca layers, leading to a Ca/Ag/Ca base, allowed to obtain a large value of common-emitter current gain, but still retaining the permeable-base transistor character. This kind of vertical devices produced by simple technologies offer attractive new possibilities due to the large variety of available molecular semiconductors, opening the possibility of incorporating new functionalities in silicon-based devices.

APA, Harvard, Vancouver, ISO, and other styles

21

Markina, Daria I., Anatoly P. Pushkarev, Ivan I. Shishkin, Filipp E. Komissarenko, Alexander S. Berestennikov, Alexey S. Pavluchenko, Irina P. Smirnova, et al. "Perovskite nanowire lasers on low-refractive-index conductive substrate for high-Q and low-threshold operation." Nanophotonics 9, no. 12 (June 24, 2020): 3977–84. http://dx.doi.org/10.1515/nanoph-2020-0207.

Full text

Abstract:

AbstractOver the last five years, inorganic lead halide perovskite nanowires have emerged as prospective candidates to supersede standard semiconductor analogs in advanced photonic designs and optoelectronic devices. In particular, CsPbX3 (X = Cl, Br, I) perovskite materials have great advantages over conventional semiconductors such as defect tolerance, highly efficient luminescence, and the ability to form regularly shaped nano- and microcavities from solution via fast crystallization. However, on the way of electrically pumped lasing, the perovskite nanowires grown on transparent conductive substrates usually suffer from strong undesirable light leakage increasing their threshold of lasing. Here, we report on the integration of CsPbBr3 nanowires with nanostructured indium tin oxide substrates possessing near-unity effective refractive index and high conductivity by using a simple wet chemical approach. Surface passivation of the substrates is found out to govern the regularity of the perovskite resonators’ shape. The nanowires show room-temperature lasing with ultrahigh quality factors (up to 7860) which are up to four times higher than that of similar structures on a flat indium tin oxide layer, resulting in more than twofold reduction of the lasing threshold for the nanostructured substrate. Numerical modeling of eigenmodes of the nanowires confirms the key role of low-refractive-index substrate for improved light confinement in the Fabry–Pérot cavity which results in superior laser performance.

APA, Harvard, Vancouver, ISO, and other styles

22

Singh, Ravi Chand, Manmeet Pal Singh, and Hardev Singh Virk. "Applications of Nanostructured Materials as Gas Sensors." Solid State Phenomena 201 (May 2013): 131–58. http://dx.doi.org/10.4028/www.scientific.net/ssp.201.131.

Full text

Abstract:

Gas detection instruments are increasingly needed for industrial health and safety, environmental monitoring, and process control. To meet this demand, considerable research into new sensors is underway, including efforts to enhance the performance of traditional devices, such as resistive metal oxide sensors, through nanoengineering. The resistance of semiconductors is affected by the gaseous ambient. The semiconducting metal oxides based gas sensors exploit this phenomenon. Physical chemistry of solid metal surfaces plays a dominant role in controlling the gas sensing characteristics. Metal oxide sensors have been utilized for several decades for low-cost detection of combustible and toxic gases. Recent advances in nanomaterials provide the opportunity to dramatically increase the response of these materials, as their performance is directly related to exposed surface volume. Proper control of grain size remains a key challenge for high sensor performance. Nanoparticles of SnO2have been synthesized through chemical route at 5, 25 and 50°C. The synthesized particles were sintered at 400, 600 and 800°C and their structural and morphological analysis was carried out using X-ray diffraction (XRD) and transmission electron microscopy (TEM). The reaction temperature is found to be playing a critical role in controlling nanostructure sizes as well as agglomeration. It has been observed that particle synthesized at 5 and 50°C are smaller and less agglomerated as compared to the particles prepared at 25°C. The studies revealed that particle size and agglomeration increases with increase in sintering temperature. Thick films gas sensors were fabricated using synthesized tin dioxide powder and sensing response of all the sensors to ethanol vapors was investigated at different temperatures and concentrations. The investigations revealed that sensing response of SnO2nanoparticles is size dependent and smaller particles display higher sensitivity. Table of Contents

APA, Harvard, Vancouver, ISO, and other styles

23

Murzin, Serguei P. "Formation of ZnO/CuO Heterostructures Based on Quasi-One-Dimensional Nanomaterials." Applied Sciences 13, no. 1 (December 30, 2022): 488. http://dx.doi.org/10.3390/app13010488.

Full text

Abstract:

Nanostructured metal oxides are of great interest both for advanced research and for a wide range of applications that contribute to the increasing demands of electronics, photonics, catalysis, sensorics, and other high-tech industries and are being actively researched and developed. One-dimensional nanocrystal arrays of copper and zinc oxides have become prominent in optoelectronic devices and energy conversion systems. However, although desirable improved properties have been demonstrated, the morphology of materials containing copper and zinc oxide nanowires is extremely sensitive to synthesis conditions and difficult to control. Studies focused on the morphology control of such quasi-one-dimensional materials are not numerous, so the consideration of this issue is still relevant. The characteristics of devices based on such oxide materials can be improved by taking advantage of nanoheterojunctions. A special feature is the possibility of forming a polycrystalline heterojunction in a system of semiconductors belonging to different crystalline syngonies. Currently, much attention is devoted to developing reliable methods of obtaining such nanomaterials, including those, based on processes exploiting novel physical effects. Possibilities of synthesis by pulse-periodic laser irradiation of arrays of quasi-one-dimensional ZnO nanostructures with varying micromorphology on metallic substrates, as well as the creation of ZnO/CuO heterostructures based on ZnO nanowires, were considered. The main distinguishing feature of this approach was the use of laser-induced vibrations to intensify diffusion processes in the solid phase of metallic materials as compared to the simple effects of laser beam heating. Expanding the area of application of the advanced method of creating oxide heterostructures requires a detailed and comprehensive study of new possibilities used to form structures with improved physical properties.

APA, Harvard, Vancouver, ISO, and other styles

24

Mandić, Vilko, Stanislav Kurajica, Milivoj Plodinec, and Ivana Panžić. "Thermal Stability and Utilization of 1D-Nanostructured Co3O4 Rods Derived by Simple Solvothermal Processing." Catalysts 12, no. 10 (October 2, 2022): 1162. http://dx.doi.org/10.3390/catal12101162.

Full text

Abstract:

For p-type semiconductor nanoparticles, such as the cobalt oxide spinel, enhancing the nanoparticle geometry can expose more of the surface and bring up the sensitivity and applicability, pointing to even more advantageous behaviour in comparison to n-type semiconductors which are known for a somewhat faster reactivity. Here, we present a strategy that relies on fostering a simple synthetic route that can deliver reasonably or comparably performing p-type-semiconducting partially 1D-Co3O4 material prepared under less technically and economically demanding conditions. Structurally monophasic Co3O4 nanoparticles with a spinel structure were indicated by powder X-ray diffraction, while the presence of traces of organic-phase residuals in otherwise chemically homogeneous material was observed by Fourier-transform infrared spectroscopy. Scanning electron microscopy further showed that the observed fine nanoparticle matter formed agglomerates with the possible presence of rod-like formations. Interestingly, using transmission electron microscopy, it was possible to reveal that the agglomerates of the fine nanoparticulated material were actually nanostructured, i.e., the presence of 1D-shaped Co3O4 rods embedded in fine nanoparticulated matrix was confirmed. In conjunction with the N2 adsorption–desorption isotherms, discussion about the orientation, exposure of nanostructured rod domains, and derivative geometry parameters was possible. The nanostructured Co3O4 material was shown to be stable up to 800 °C whereat the decomposition to CoO takes place. The specific surface area of the nanostructured sample was raised. For the purpose of testing the photoactivity of the prepared samples, simple sorption/photodegradation tests using methylene blue as the model pollutant were performed. The degradation performance of the prepared nanostructured Co3O4 was better described by a pseudo-second-order fit, suggesting that the prepared material is worth further development toward improved and stable immobilized photocatalysts.

APA, Harvard, Vancouver, ISO, and other styles

25

Betty, C. A., Sipra Choudhury, and Alpa Shah. "Nanostructured metal oxide semiconductors and composites for reliable trace gas sensing at room temperature." Surfaces and Interfaces 36 (February 2023): 102560. http://dx.doi.org/10.1016/j.surfin.2022.102560.

Full text

APA, Harvard, Vancouver, ISO, and other styles

26

Smirnov, A., A. Stsiapanau, Y. Mukha, Ya Satskevich, A. Martinovich, and A. Maksimov. "Paper No P19: Aluminum Nanostructured Coatings as Alternatives to Metal Oxide and Transparent Semiconductors." SID Symposium Digest of Technical Papers 44 (September 2013): 68–69. http://dx.doi.org/10.1002/sdtp.27.

Full text

APA, Harvard, Vancouver, ISO, and other styles

27

Ahmed, Hasan, and Viktoriia E. Babicheva. "Nanostructured Tungsten Disulfide WS2 as Mie Scatterers and Nanoantennas." MRS Advances 5, no. 35-36 (2020): 1819–26. http://dx.doi.org/10.1557/adv.2020.173.

Full text

Abstract:

ABSTRACTNanoparticles of high-refractive-index materials like semiconductors can achieve confinement of light at the subwavelength scale because of the excitation of Mie resonances. The nanostructures out of high-refractive-index materials have extensively been studied theoretically and realized in experiments exploring a wide range of photonic applications. Recently, transition metal dichalcogenides (TMDCs) from the family of van der Waals layered materials have been shown to exhibit tailorable optical properties along with high refractive index and strong anisotropy. We envision that TMDCs are a promising material platform for designing metasurfaces and ultra-thin optical elements: these van der Waals materials show a strong spectral response on light excitations in visible and near-infrared ranges, and metasurface properties can be controlled by nanoantenna dimensions and their arrangement. In this work, we investigate a periodic array of disk-shaped nanoantennas made of a TMDC material, tungsten disulfide WS2, placed on top of a silicon layer and oxide substrate. We show that the nanostructure resonance in TMDC disk-shaped nanoantenna array can be controlled by the variation in silicon layer thickness and have a dependence on the presence of index-match superstrate cover. We also report on the spectral features in absorption and reflection profiles of the same structure with different surrounding index.

APA, Harvard, Vancouver, ISO, and other styles

28

Saleem, T., R. A. Sarfaraz, I. Ahmed, H. Zulfiqar, Y. Iqbal, I. Saeed, M. Ashraf, and U. Anwar. "Synthesis and characterization of nanostructured ternary composites of graphene oxide/Fe3O4/NiO for waste water treatment." Digest Journal of Nanomaterials and Biostructures 17, no. 4 (November 1, 2022): 1203–10. http://dx.doi.org/10.15251/djnb.2022.174.1203.

Full text

Abstract:

Photocatalysis using solar energy and semiconductors is widely used in the purification of air and the processing of wastewater. Present study deal with cost-effective GO synthesis, supporting NiO/Fe3O4 ternary nanocomposites; for the rapid photocatalytic degradation of the Rhodamine B Dye. For this purpose, nickel oxide nanoparticles and iron oxide nanoparticles were synthesized by hydrothermal method. Synthesis of graphene oxide was done by using modified hummers method. These trimetallic nanoparticles were characterized by FTIR (Fourier Transform Infrared Spectroscopy), Scanning Electron Microscopy (SEM) and X-ray Diffraction Crystallography (XRD) for structure, shape and composition determination. The photocatalytic degradation of Rhodamine B dye was conducted and various parameters like catalyst amount, dye concentration, pH and contact time optimization were performed to evaluate dye degradation efficiency of Fe3O4/NiO/Graphene trimetallic nanoparticles. Kinetic models were studied to check degradation rate and Pseudo 1st order kinetic model was most suitable to the experimental data of dye degradation.

APA, Harvard, Vancouver, ISO, and other styles

29

Custodio, Cyron L., John Lemuel G. Untalasco, and Menandro C. Marquez. "Preparation of Cuprous Oxide/Cobaltous Oxide Nanostructured Composite with the Aid of Polyethylene Glycol and Ultrasonic Sound." Materials Science Forum 916 (March 2018): 50–54. http://dx.doi.org/10.4028/www.scientific.net/msf.916.50.

Full text

Abstract:

Metal oxide semiconductors such as cobaltous oxide (Co3O4) and cuprous oxide (Cu2O) have caught the attention of many researchers due to their wide variety of applications. The attachment of Cu2O to Co3O4 was assisted by polyethylene glycol and the nanostructuring by ultrasonic sound. X-ray Diffraction (XRD) analysis of the fabricated composite reported characteristic peaks for crystalline Co3O4 and Cu2O. Results from Energy Dispersive X-ray (EDX) Spectroscopy showed the presence of cobalt, copper, and oxygen atoms which supports the result obtained in XRD. Cauliflower to nearly spherical shaped Cu2O - Co3O4 nanostructures were formed as observed in the Scanning Electron Micrographs (SEM) with a mean diameter of 0.5-1.0 μm. the shape of the composite and its surface morphology was altered with the use of different precursor materials for the synthesis of the Co3O4 seed. A blue shift in the UV-vis was observed upon the use of nitrate based precursor indicating the presence of smaller and finer particles in the composite. Overall results prove that Cu2O and Co3O4 can be synthesized using a facile solution approach with the aid of PEG and ultrasonic sound its application in the field of photocatalysis is probable.

APA, Harvard, Vancouver, ISO, and other styles

30

ElZein, Basma, Mutalifu Abulikemu, Ahmad S. Barham, Alia Al-Kilani, Mohammed I. Alkhatab, Samir M. Hamdan, Elhadj Dogheche, and Ghassan E. Jabbour. "In Situ Growth of PbS Nanoparticles without Organic Linker on ZnO Nanostructures via Successive Ionic Layer Adsorption and Reaction (SILAR)." Coatings 12, no. 10 (October 6, 2022): 1486. http://dx.doi.org/10.3390/coatings12101486.

Full text

Abstract:

The process of effective solar energy harvesting and conversion requires efficient photon absorption, followed by charge generation and separation, then electron transfer. Nanostructured materials have been considered as potential building blocks for the development of future generations of solar cells. Much attention has been given to wide-bandgap semiconductor nanowires, combined and sensitized with low-bandgap semiconductors effectively attached to the nanowires for low-cost and highly efficient solar cells. Here, the in situ growth of lead sulfide (PbS) nanoparticles on the surface of zinc oxide (ZnO) nanowires grown by the Successive Ionic Layer Adsorption and Reaction (SILAR) technique is presented for different numbers of cycles. The morphology and structure of PbS nanoparticles are confirmed by Scanning Electron Microscopy (SEM), revealing the decoration of the nanowires with the PbS nanoparticles, Transmission Electron Microscopy (TEM) and HR-TEM, showing the tight attachment of PbS nanoparticles on the surface of the ZnO nanowires. The Selected Area Electron Diffraction (SAED) confirms the crystallization of the PbS. Photoluminescence spectra show a broad and more intense deep-level emission band.

APA, Harvard, Vancouver, ISO, and other styles

31

Gnisci, Andrea, Antonio Fotia, Lucio Bonaccorsi, and Andrea Donato. "Effect of Working Atmospheres on the Detection of Diacetyl by Resistive SnO2 Sensor." Applied Sciences 12, no. 1 (December 31, 2021): 367. http://dx.doi.org/10.3390/app12010367.

Full text

Abstract:

Nanostructured metal oxide semiconductors (MOS) are considered proper candidates to develop low cost and real-time resistive sensors able to detect volatile organic compounds (VOCs), e.g., diacetyl. Small quantities of diacetyl are generally produced during the fermentation and storage of many foods and beverages, conferring a typically butter-like aroma. Since high diacetyl concentrations are undesired, its monitoring is fundamental to identify and characterize the quality of products. In this work, a tin oxide sensor (SnO2) is used to detect gaseous diacetyl. The effect of different working atmospheres (air, N2 and CO2), as well as the contemporary presence of ethanol vapors, used to reproduce the typical alcoholic fermentation environment, are evaluated. SnO2 sensor is able to detect diacetyl in all the analyzed conditions, even when an anaerobic environment is considered, showing a detection limit lower than 0.01 mg/L and response/recovery times constantly less than 50 s.

APA, Harvard, Vancouver, ISO, and other styles

32

Imparato, Claudio, Aurelio Bifulco, Brigida Silvestri, and Giuseppe Vitiello. "Recent Advances in Endocrine Disrupting Compounds Degradation through Metal Oxide-Based Nanomaterials." Catalysts 12, no. 3 (March 3, 2022): 289. http://dx.doi.org/10.3390/catal12030289.

Full text

Abstract:

Endocrine Disrupting Compounds (EDCs) comprise a class of natural or synthetic molecules and groups of substances which are considered as emerging contaminants due to their toxicity and danger for the ecosystems, including human health. Nowadays, the presence of EDCs in water and wastewater has become a global problem, which is challenging the scientific community to address the development and application of effective strategies for their removal from the environment. Particularly, catalytic and photocatalytic degradation processes employing nanostructured materials based on metal oxides, mainly acting through the generation of reactive oxygen species, are widely explored to eradicate EDCs from water. In this review, we report the recent advances described by the major publications in recent years and focused on the degradation processes of several classes of EDCs, such as plastic components and additives, agricultural chemicals, pharmaceuticals, and personal care products, which were realized by using novel metal oxide-based nanomaterials. A variety of doped, hybrid, composite and heterostructured semiconductors were reported, whose performances are influenced by their chemical, structural as well as morphological features. Along with photocatalysis, alternative heterogeneous advanced oxidation processes are in development, and their combination may be a promising way toward industrial scale application.

APA, Harvard, Vancouver, ISO, and other styles

33

Nicolaescu, Mircea, Viorel Aurel Serban, Carmen Lazau, Cornelia Bandas, Corina Orha, Melinda Vajda, and Emilia Florina Binchiciu. "Morphology Changes in the One-Step Synthesis of Cu<sub>2</sub>O/ CuO by Dealloying Amorphous Ribbons in Alkaline Solution." Key Engineering Materials 952 (August 18, 2023): 35–41. http://dx.doi.org/10.4028/p-cj0lbt.

Full text

Abstract:

The dealloying technique has been a well-known process since antiquity, but recently it has started to be used to produce nonporous metals and metal oxide semiconductors for various electrochemical applications. The dealloying process is carried out in both acidic and basic solutions, depending on the base material and the desired application. In this study, Cu-based amorphous ribbons were dealloyed in alkaline aqueous solution at room temperature, keeping the temperature constant and varying the concentration of the solution. This process has the advantage that both dealloying of the ribbons and nanostructured copper oxide synthesis on their surface is obtained in one step. For the preparation of copper-based amorphous ribbons, the melt-spinning process was used, and the composite obtained consisting of nanopores decorated with Cu2O/CuO nanoparticles makes it an ideal candidate for electrochemical applications. For the investigation of the structural, morphological, and optical properties of the obtained materials, X-ray diffraction (XRD) and scanning electron microscopy (SEM).

APA, Harvard, Vancouver, ISO, and other styles

34

Gnawali, Guna Nidha, Shankar P. Shrestha, Khem N. Poudyal, Indra B. Karki, and Ishwar Koirala. "Study on the effect of growth-time and seed-layers of Zinc Oxide nanostructured thin film prepared by the hydrothermal method for liquefied petroleum gas sensor application." BIBECHANA 16 (November 22, 2018): 145–53. http://dx.doi.org/10.3126/bibechana.v16i0.21557.

Full text

Abstract:

Gas sensors are devices that can convert the concentration of an analytic gas into an electronic signal. Zinc oxide (ZnO) is an important n-type metal oxide semiconductor which has been utilized as gas sensor for several decades. In this work, ZnO nanostructured films were synthesized by a hydrothermal route from ZnO seeds and used as a liquefied petroleum gas (LPG) sensor. At first ZnO seed layers were deposited on glass substrates by using spin coating method, then ZnO nanostructured were grown on these substrates by using hydrothermal growth method for different time duration. The effect of growth time and seed layers of ZnO nanostructured on its structural, optical, and electrical properties was studied. These nanostructures were characterized by X-ray diffraction, scanning electron microscopy, optical spectroscopy, and four probes sheet resistance measurement unit. The sensing performances of the synthetic ZnO nanostructures were investigated for LPG.XRD showed that all the ZnO nanostructures were hexagonal crystal structure with preferential orientation. SEM reviled that the size of nanostructure increased with increase in growth time. Band gap and sheet resistance for ZnO nanostructured thin film decreased with increase in growth time. ZnO nanostructured thin film showed high sensitivity towards LPG gas. The sensitivity of the film is observed to increase with increase in no of seed layers as well as growth time. The dependence of the LPG sensing properties on the different growth time of ZnO nanostructured was investigated. The sensing performances of the film were investigated by measured change in sheet resistance under expose to LPG gas. BIBECHANA 16 (2019) 145-153

APA, Harvard, Vancouver, ISO, and other styles

35

Donato, N., and G. Neri. "Plasma Technologies in the Synthesis and Treatment of Nanostructured Metal Oxide Semiconductors for Gas Sensing: A Short Review." Nanoscience and Nanotechnology Letters 4, no. 3 (March 1, 2013): 211–27. http://dx.doi.org/10.1166/nnl.2012.1323.

Full text

APA, Harvard, Vancouver, ISO, and other styles

36

Sharma, Swati, and Marc Madou. "A new approach to gas sensing with nanotechnology." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 370, no. 1967 (May 28, 2012): 2448–73. http://dx.doi.org/10.1098/rsta.2011.0506.

Full text

Abstract:

Nanosized gas sensor elements are potentially faster, require lower power, come with a lower limit of detection, operate at lower temperatures, obviate the need for expensive catalysts, are more heat shock resistant and might even come at a lower cost than their macro-counterparts. In the last two decades, there have been important developments in two key areas that might make this promise a reality. First is the development of a variety of very good performing nanostructured metal oxide semiconductors (MOSs), the most commonly used materials for gas sensing; and second are advances in very low power loss miniaturized heater elements. Advanced nano- or micro–nanogas sensors have attracted much attention owing to a variety of possible applications. In this article, we first discuss the mechanism underlying MOS-based gas sensor devices, then we describe the advances that have been made towards MOS nanostructured materials and the progress towards low-power nano- and microheaters. Finally, we attempt to design an ideal nanogas sensor by combining the best nanomaterial strategy with the best heater implementation. In this regard, we end with a discussion of a suspended carbon nanowire-based gas sensor design and the advantages it might offer compared with other more conventional gas sensor devices.

APA, Harvard, Vancouver, ISO, and other styles

37

Garcia-Peiro, Jose I., Javier Bonet-Aleta, Carlos J. Bueno-Alejo, and Jose L. Hueso. "Recent Advances in the Design and Photocatalytic Enhanced Performance of Gold Plasmonic Nanostructures Decorated with Non-Titania Based Semiconductor Hetero-Nanoarchitectures." Catalysts 10, no. 12 (December 14, 2020): 1459. http://dx.doi.org/10.3390/catal10121459.

Full text

Abstract:

Plasmonic photocatalysts combining metallic nanoparticles and semiconductors have been aimed as versatile alternatives to drive light-assisted catalytic chemical reactions beyond the ultraviolet (UV) regions, and overcome one of the major drawbacks of the most exploited photocatalysts (TiO2 or ZnO). The strong size and morphology dependence of metallic nanostructures to tune their visible to near-infrared (vis-NIR) light harvesting capabilities has been combined with the design of a wide variety of architectures for the semiconductor supports to promote the selective activity of specific crystallographic facets. The search for efficient heterojunctions has been subjected to numerous studies, especially those involving gold nanostructures and titania semiconductors. In the present review, we paid special attention to the most recent advances in the design of gold-semiconductor hetero-nanostructures including emerging metal oxides such as cerium oxide or copper oxide (CeO2 or Cu2O) or metal chalcogenides such as copper sulfide or cadmium sulfides (CuS or CdS). These alternative hybrid materials were thoroughly built in past years to target research fields of strong impact, such as solar energy conversion, water splitting, environmental chemistry, or nanomedicine. Herein, we evaluate the influence of tuning the morphologies of the plasmonic gold nanostructures or the semiconductor interacting structures, and how these variations in geometry, either individual or combined, have a significant influence on the final photocatalytic performance.

APA, Harvard, Vancouver, ISO, and other styles

38

Aseev, Aleksander Leonidovich, Alexander Vasilevich Latyshev, and Anatoliy Vasilevich Dvurechenskii. "Semiconductor Nanostructures for Modern Electronics." Solid State Phenomena 310 (September 2020): 65–80. http://dx.doi.org/10.4028/www.scientific.net/ssp.310.65.

Full text

Abstract:

Modern electronics is based on semiconductor nanostructures in practically all main parts: from microprocessor circuits and memory elements to high frequency and light-emitting devices, sensors and photovoltaic cells. Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) with ultimately low gate length in the order of tens of nanometers and less is nowadays one of the basic elements of microprocessors and modern electron memory chips. Principally new physical peculiarities of semiconductor nanostructures are related to quantum effects like tunneling of charge carriers, controlled changing of energy band structure, quantization of energy spectrum of a charge carrier and a pronounced spin-related phenomena. Superposition of quantum states and formation of entangled states of photons offers new opportunities for the realization of quantum bits, development of nanoscale systems for quantum cryptography and quantum computing. Advanced growth techniques such as molecular beam epitaxy and chemical vapour epitaxy, atomic layer deposition as well as optical, electron and probe nanolithography for nanostructure fabrication have been widely used. Nanostructure characterization is performed using nanometer resolution tools including high-resolution, reflection and scanning electron microscopy as well as scanning tunneling and atomic force microscopy. Quantum properties of semiconductor nanostructures have been evaluated from precise electrical and optical measurements. Modern concepts of various semiconductor devices in electronics and photonics including single-photon emitters, memory elements, photodetectors and highly sensitive biosensors are developed very intensively. The perspectives of nanostructured materials for the creation of a new generation of universal memory and neuromorphic computing elements are under lively discussion. This paper is devoted to a brief description of current achievements in the investigation and modeling of single-electron and single-photon phenomena in semiconductor nanostructures, as well as in the fabrication of a new generation of elements for micro-, nano, optoelectronics and quantum devices.

APA, Harvard, Vancouver, ISO, and other styles

39

Konstantinova, Elizaveta A., Anton A. Minnekhanov, Alexander I. Kokorin, Tatyana V. Sviridova, and Dmitry V. Sviridov. "Determination of the Energy Levels of Paramagnetic Centers in the Band Gap of Nanostructured Oxide Semiconductors Using EPR Spectroscopy." Journal of Physical Chemistry C 122, no. 18 (April 17, 2018): 10248–54. http://dx.doi.org/10.1021/acs.jpcc.8b01621.

Full text

APA, Harvard, Vancouver, ISO, and other styles

40

Ковалева, Анастасия Сергеевна, Борис Владимирович Сладкопевцев, Алексей Алексеевич Самсонов, Светлана Ивановна Алферова, Данила Геннадьевич Ковалев, Сергей Александрович Титов, Никита Дмитриевич Пряхин, and Ирина Яковлевна Миттова. "The influence of the physicochemical nature of the components of the V2O5/GaAs, MnO2/GaAs, V2O5/InP, MnO2/InP, TiO2/InP, and SnO2/InP heterostructures and the oxidation conditions on the surface morphology of the synthesised films." Kondensirovannye sredy i mezhfaznye granitsy = Condensed Matter and Interphases 24, no. 1 (March 15, 2022): 33–44. http://dx.doi.org/10.17308/kcmf.2022.24/9053.

Full text

Abstract:

The formation of oxide functional films on the surface of semiconductors is a serious technological challenge, which is even more complicated in the nanometre thickness range. It is necessary to form films with specified values of thickness, resistivity, and a certain surface morphology for practical applications. Such films are used in micro- and optoelectronics, environmental monitoring, and alternative energy devices. The goal of this work is to establish the features of the surface morphology of thin films formed as a result of the thermal oxidation of the MnO2/GaAs, V2O5/GaAs, V2O5/InP, MnO2/InP, TiO2/InP, and SnO2/InP heterostructures depending on the physicochemical nature of the components and the oxidation conditions. The synthesis of thin films on the InP and GaAs surfaces was carried out by thermal oxidation under the influence of magnetron-deposited layers of chemostimulator-modifiers. The thickness of the formed films and their composition were determined by laser ellipsometry, X-ray phase analysis, and infra-red spectroscopy. The scanning tunnel and atomic force microscopy were used to determine the morphological characteristics of the films and their dependence on the type of semiconductor substrate, the nature of the chemostimulator-modifier, and the conditions of the thermal oxidation. The application to the GaАs and InP surfaces of the most effective chemostimulator-modifiers (V2O5 and MnO2) of thermal oxidation and higher temperatures of the oxidation process contributed to the formation of smoother and nanostructured films.

APA, Harvard, Vancouver, ISO, and other styles

41

Alhalaili, Badriyah, Ahmad Al-Duweesh, Ileana Nicoleta Popescu, Ruxandra Vidu, Luige Vladareanu, and M. Saif Islam. "Improvement of Schottky Contacts of Gallium Oxide (Ga2O3) Nanowires for UV Applications." Sensors 22, no. 5 (March 6, 2022): 2048. http://dx.doi.org/10.3390/s22052048.

Full text

Abstract:

Interest in the synthesis and fabrication of gallium oxide (Ga2O3) nanostructures as wide bandgap semiconductor-based ultraviolet (UV) photodetectors has recently increased due to their importance in cases of deep-UV photodetectors operating in high power/temperature conditions. Due to their unique properties, i.e., higher surface-to-volume ratio and quantum effects, these nanostructures can significantly enhance the sensitivity of detection. In this work, two Ga2O3 nanostructured films with different nanowire densities and sizes obtained by thermal oxidation of Ga on quartz, in the presence and absence of Ag catalyst, were investigated. The electrical properties influenced by the density of Ga2O3 nanowires (NWs) were analyzed to define the configuration of UV detection. The electrical measurements were performed on two different electric contacts and were located at distances of 1 and 3 mm. Factors affecting the detection performance of Ga2O3 NWs film, such as the distance between metal contacts (1 and 3 mm apart), voltages (5–20 V) and transient photocurrents were discussed in relation to the composition and nanostructure of the Ga2O3 NWs film.

APA, Harvard, Vancouver, ISO, and other styles

42

Gyanwali, Gunanidhi. "Studying the Effect of Seed-layers of Zinc Oxide Nanostructured Thin Film for Liquefied Petroleum Gas Sensor Application." Molung Educational Frontier 10 (December 31, 2020): 41–49. http://dx.doi.org/10.3126/mef.v10i0.34056.

Full text

Abstract:

Gas sensors are devices that can convert the concentration of an analyte gas into an electronic signal. Zinc oxide (ZnO) is one of the most important n-type metal oxide semiconductor which has been utilized as gas sensor for many years. In this work, ZnO nanostructured films were synthesized by a hydrothermal growth from ZnO seeds and used as a liquefied petroleum gas (LPG) sensor. At first ZnO seed layers were deposited on glass substrates by using spin coating method, then ZnO nanostructured were grown on these substrates by using hydrothermal growth method. The effect of seed layers of ZnO nanostructured on its structural, optical, and electrical properties was studied. These nanostructures were characterized by scanning electron microscopy, X-ray diffraction, optical spectroscopy, and sheet resistance measurement unit. The sensing performances of the synthetic ZnO nanostructures were investigated for LPG. XRD showed that all the ZnO nanostructures were hexagonal crystal structure. ZnO nanostructured thin film showed high sensitivity towards LPG gas. The sensitivity of the film is observed to increase with increase in number of seed layers. The sensitivity of the film was investigated by measured change in sheet resistance under with LPG gas.

APA, Harvard, Vancouver, ISO, and other styles

43

Yoon, Sang-Hyeok, and Kyo-Seon Kim. "Doping Mo on Tungsten Oxide Thin Film and Photoelectrochemical Measurement." Journal of Nanoscience and Nanotechnology 21, no. 9 (September 1, 2021): 4813–17. http://dx.doi.org/10.1166/jnn.2021.19256.

Full text

Abstract:

Tungsten oxide (WO3) is semiconductor material which can be used for various applications. Especially, one-dimensional (1-D) nanostructured WO3 shows the high photoelectrochemical (PEC) performance due to high surface area and short transport route of electron–hole pair. The flame vapor deposition (FVD) process is an efficient and economical method for preparation of the 1-D nanos-tructured WO3 thin film. Molybdenum doping is a well-known method to improve the PEC performance of WO3 by reducing band gap and increasing electrical property. In this study, we prepared the 1-D WO3 nanostructures doped with Mo by FVD single step process. We confirmed that Mo was successfully doped on WO3 without changing significantly the original nanostructure, crystal structure and chemical bonding state of WO3 thin film. As a result of PEC measurement, the pho-tocurrent densities of WO3 thin film with Mo doping were higher by about 1.4 to 2 times (for applied voltage above 0.7 V vs. SCE) than those without Mo doping.

APA, Harvard, Vancouver, ISO, and other styles

44

Gole, James L., and William Laminack. "Nanostructure-directed chemical sensing: The IHSAB principle and the dynamics of acid/base-interface interaction." Beilstein Journal of Nanotechnology 4 (January 14, 2013): 20–31. http://dx.doi.org/10.3762/bjnano.4.3.

Full text

Abstract:

Nanostructure-decorated n-type semiconductor interfaces are studied in order to develop chemical sensing with nanostructured materials. We couple the tenets of acid/base chemistry with the majority charge carriers of an extrinsic semiconductor. Nanostructured islands are deposited in a process that does not require self-assembly in order to direct a dominant electron-transduction process that forms the basis for reversible chemical sensing in the absence of chemical-bond formation. Gaseous analyte interactions on a metal-oxide-decorated n-type porous silicon interface show a dynamic electron transduction to and from the interface depending upon the relative strength of the gas and metal oxides. The dynamic interaction of NO with TiO2, SnO2, NiO, Cu x O, and Au x O (x >> 1), in order of decreasing acidity, demonstrates this effect. Interactions with the metal-oxide-decorated interface can be modified by the in situ nitridation of the oxide nanoparticles, enhancing the basicity of the decorated interface. This process changes the interaction of the interface with the analyte. The observed change to the more basic oxinitrides does not represent a simple increase in surface basicity but appears to involve a change in molecular electronic structure, which is well explained by using the recently developed IHSAB model. The optical pumping of a TiO2 and TiO2− x N x decorated interface demonstrates a significant enhancement in the ability to sense NH3 and NO2. Comparisons to traditional metal-oxide sensors are also discussed.

APA, Harvard, Vancouver, ISO, and other styles

45

Bisquert, Juan, Francisco Fabregat-Santiago, Iván Mora-Seró, Germà Garcia-Belmonte, Eva M. Barea, and Emilio Palomares. "A review of recent results on electrochemical determination of the density of electronic states of nanostructured metal-oxide semiconductors and organic hole conductors." Inorganica Chimica Acta 361, no. 3 (February 2008): 684–98. http://dx.doi.org/10.1016/j.ica.2007.05.032.

Full text

APA, Harvard, Vancouver, ISO, and other styles

46

Witkiewicz, Zygfryd, Krzysztof Jasek, and Michał Grabka. "Semiconductor Gas Sensors for Detecting Chemical Warfare Agents and Their Simulants." Sensors 23, no. 6 (March 20, 2023): 3272. http://dx.doi.org/10.3390/s23063272.

Full text

Abstract:

On-site detection of chemical warfare agents (CWAs) can be performed by various analytical techniques. Devices using well-established techniques such as ion mobility spectrometry, flame photometry, infrared and Raman spectroscopy or mass spectrometry (usually combined with gas chromatography) are quite complex and expensive to purchase and operate. For this reason, other solutions based on analytical techniques well suited to portable devices are still being sought. Analyzers based on simple semiconductor sensors may be a potential alternative to the currently used CWA field detectors. In sensors of this type, the conductivity of the semiconductor layer changes upon interaction with the analyte. Metal oxides (both in the form of polycrystalline powders and various nanostructures), organic semiconductors, carbon nanostructures, silicon and various composites that are a combination of these materials are used as a semiconductor material. The selectivity of a single oxide sensor can be adjusted to specific analytes within certain limits by using the appropriate semiconductor material and sensitizers. This review presents the current state of knowledge and achievements in the field of semiconductor sensors for CWA detection. The article describes the principles of operation of semiconductor sensors, discusses individual solutions used for CWA detection present in the scientific literature and makes a critical comparison of them. The prospects for the development and practical application of this analytical technique in CWA field analysis are also discussed.

APA, Harvard, Vancouver, ISO, and other styles

47

Jamwal, Nishant Singh, and Amirkianoosh Kiani. "Gallium Oxide Nanostructures: A Review of Synthesis, Properties and Applications." Nanomaterials 12, no. 12 (June 15, 2022): 2061. http://dx.doi.org/10.3390/nano12122061.

Full text

Abstract:

Gallium oxide, as an emerging semiconductor, has attracted a lot of attention among researchers due to its high band gap (4.8 eV) and a high critical field with the value of 8 MV/cm. This paper presents a review on different chemical and physical techniques for synthesis of nanostructured β-gallium oxide, as well as its properties and applications. The polymorphs of Ga2O3 are highlighted and discussed along with their transformation state to β-Ga2O3. Different processes of synthesis of thin films, nanostructures and bulk gallium oxide are reviewed. The electrical and optical properties of β-gallium oxide are also highlighted, based on the synthesis methods, and the techniques for tuning its optical and electrical properties compared. Based on this information, the current, and the possible future, applications for β-Ga2O3 nanostructures are discussed.

APA, Harvard, Vancouver, ISO, and other styles

48

Yao, Yu, Dandan Sang, Liangrui Zou, Qinglin Wang, and Cailong Liu. "A Review on the Properties and Applications of WO3 Nanostructure−Based Optical and Electronic Devices." Nanomaterials 11, no. 8 (August 22, 2021): 2136. http://dx.doi.org/10.3390/nano11082136.

Full text

Abstract:

Tungsten oxide (WO3) is a wide band gap semiconductor with unintentionally n−doping performance, excellent conductivity, and high electron hall mobility, which is considered as a candidate material for application in optoelectronics. Several reviews on WO3 and its derivatives for various applications dealing with electrochemical, photoelectrochemical, hybrid photocatalysts, electrochemical energy storage, and gas sensors have appeared recently. Moreover, the nanostructured transition metal oxides have attracted considerable attention in the past decade because of their unique chemical, photochromic, and physical properties leading to numerous other potential applications. Owing to their distinctive photoluminescence (PL), electrochromic and electrical properties, WO3 nanostructure−based optical and electronic devices application have attracted a wide range of research interests. This review mainly focuses on the up−to−date progress in different advanced strategies from fundamental analysis to improve WO3 optoelectric, electrochromic, and photochromic properties in the development of tungsten oxide−based advanced devices for optical and electronic applications including photodetectors, light−emitting diodes (LED), PL properties, electrical properties, and optical information storage. This review on the prior findings of WO3−related optical and electrical devices, as well as concluding remarks and forecasts will help researchers to advance the field of optoelectric applications of nanostructured transition metal oxides.

APA, Harvard, Vancouver, ISO, and other styles

49

Musat, Viorica, Ana Filip, Nicolae Tigau, Rodica Dinica, Elena Herbei, Cosmin Romanitan, Iuliana Mihalache, and Munizer Purica. "1D Nanostructured ZnO Layers by Microwave - Assisted Hydrothermal Synthesis." Revista de Chimie 69, no. 10 (November 15, 2018): 2788–93. http://dx.doi.org/10.37358/rc.18.10.6625.

Full text

Abstract:

ZnO 1D nanostructures have been gaining more and more advanced applications in various fields from electronics and optoelectronics to environment protection and medicine due to the synergy between the unique properties of semiconductor zinc oxide and those of 1D nanostructures. This paper investigates the microwave (MW)-assisted hydrothermal synthesis of 1D nanostructured ZnO layers grown on glass substrates to be used in optoelectronic applications. The effects of MW-irradiation power (400-600 W) and span (3-6 min) on the morphology, microstructure and optical properties (transmittance, reflectance, absorption coefficient and refractive index) of the resulted nanostructured layers were investigated by SEM, FTIR and UV-Vis-NIR spectroscopy. The band gap energy was calculated from optical absorbance spectra in UV-Vis range.The obtained ZnO nanostructured layers show optical transmittance between 58 and 87% and low reflection between 4.2-6.8 % at normal incidence of light in the visible spectra and transmittance values from 75 to 85% and reflectance between 4.8 and 6.7% in the near infrared spectra.

APA, Harvard, Vancouver, ISO, and other styles

50

Pascariu, Petronela, Carmen Gherasim, and Anton Airinei. "Metal Oxide Nanostructures (MONs) as Photocatalysts for Ciprofloxacin Degradation." International Journal of Molecular Sciences 24, no. 11 (May 31, 2023): 9564. http://dx.doi.org/10.3390/ijms24119564.

Full text

Abstract:

In recent years, organic pollutants have become a global problem due to their negative impact on human health and the environment. Photocatalysis is one of the most promising methods for the removal of organic pollutants from wastewater, and oxide semiconductor materials have proven to be among the best in this regard. This paper presents the evolution of the development of metal oxide nanostructures (MONs) as photocatalysts for ciprofloxacin degradation. It begins with an overview of the role of these materials in photocatalysis; then, it discusses methods of obtaining them. Then, a detailed review of the most important oxide semiconductors (ZnO, TiO2, CuO, etc.) and alternatives for improving their photocatalytic performance is provided. Finally, a study of the degradation of ciprofloxacin in the presence of oxide semiconductor materials and the main factors affecting photocatalytic degradation is carried out. It is well known that antibiotics (in this case, ciprofloxacin) are toxic and non-biodegradable, which can pose a threat to the environment and human health. Antibiotic residues have several negative impacts, including antibiotic resistance and disruption of photosynthetic processes.

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Nanostructured Oxide Semiconductors'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles