Download or read book Toxic Gas Sensors Using Thin Film Transistor Platform at Low Temperature written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Semiconducting metal-oxides such as SnO2, TiO2, ZnO and WO3 are commonly used for gas sensing in the form of thin film resistors (TFRs) given their high sensitivity to many vapor species, simple construction and capability for miniaturization. Furthermore, they are generally more stable than polymer-based gas sensors. However, unlike polymers, metal oxide gas sensors must typically be operated between 200-400°C to insure rapid kinetics. Another problem impacting TFR performance and reproducibility is related to poorly understood substrate-semiconductor film interactions. Space charges at this heterojunction are believed to influence chemisorption on the semiconductor-gas interface, but unfortunately, in an unpredictable manner. In this study, the feasibility of employing illumination and the thin film transistor (TFT) platform as a means of reducing operation temperature was investigated on ZnO based TFTs for gas sensors applications. Response to NO2 is observed at significantly reduced temperature. Photoconductivity measurements, performed as a function of temperature on ZnO based TFRs, indicate that this results in a photon-induced desorption process. Also, transient changes in TFT channel conductance and transistor threshold voltage are obtained with application of gate bias, suggesting that TFTs offer additional control over chemisorption at the semiconductor-gas interface.

Download or read book Toxic Gas Sensors Using Thin Film Transistor Platform at Low Temperature written by Yoonsil Jin and published by . This book was released on 2009 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: Semiconducting metal-oxides such as SnO2, TiO2, ZnO and WO3 are commonly used for gas sensing in the form of thin film resistors (TFRs) given their high sensitivity to many vapor species, simple construction and capability for miniaturization. Furthermore, they are generally more stable than polymer-based gas sensors. However, unlike polymers, metal oxide gas sensors must typically be operated between 200-400°C to insure rapid kinetics. Another problem impacting TFR performance and reproducibility is related to poorly understood substrate-semiconductor film interactions. Space charges at this heterojunction are believed to influence chemisorption on the semiconductor-gas interface, but unfortunately, in an unpredictable manner. In this study, the feasibility of employing illumination and the thin film transistor (TFT) platform as a means of reducing operation temperature was investigated on ZnO based TFTs for gas sensors applications. Response to NO2 is observed at significantly reduced temperature. Photoconductivity measurements, performed as a function of temperature on ZnO based TFRs, indicate that this results in a photon-induced desorption process. Also, transient changes in TFT channel conductance and transistor threshold voltage are obtained with application of gate bias, suggesting that TFTs offer additional control over chemisorption at the semiconductor-gas interface.

Download or read book Toxic Gas Sensors and Biosensors written by Inamuddin and published by Materials Research Forum LLC. This book was released on 2021-02-15 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book focuses on novel sensor materials and their environmental and healthcare applications, such as NO2 detection, toxic gas and biosensing, hydrazine determination, glucose sensing and the detection of toxins and pollutants on surfaces. Materials covered include catalytic nanomaterials, metal oxides, perovskites, zeolites, spinels, graphene-based gas sensors, CNT/Ni nanocomposites, glucose biosensors, single and multi-layered stacked MXenes, black phosphorus, transition metal dichalcogenides and P3OT thin films. Keywords: Toxic Gas Sensors, Biosensors, Nitrogen Dioxide Detection, Hydrazine Determination, Glucose Sensing, Catalytic Nanomaterials, Metal Oxides, Perovskites, Zeolites, Spinels, Graphene-based Gas Sensors, CNT/Ni Nanocomposites, Mxenes, Black Phosphorus, Transition Metal Dichalcogenides, P3OT Thin Films.

Download or read book Organic Thin film Transistor Based Gas Sensors for Putrescine Detection written by Jiaxin Zhu and published by . This book was released on 2018 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt: The application of organic thin film transistors (OTFTs) has been progressing in the area of sensors for decades now. For accomplishing gas sensing in ambient conditions, polymers with good air stability and high enough mobility to detect environmental variations by analytes exposure are required for the OTFT-sensors. In this work, putrescine (PUT) was selected as our primary analyte, as it has high volatility and can be emitted by decayed food products. OTFT-based sensors were made with various polymers as semiconductors to detect PUT vapor. Based on the preliminary study of gas sensing with bottom-gate, bottom-contact (BGBC) OTFTs, a gas sensing system was established with OTFT-sensors, an analyte injection platform and a signal analyzing system, which is presented in Chapter 3. Before and after gas detection, all OTFT devices were characterized by their charge carrier mobility, threshold voltage and current on/off ratio in the glovebox and in air. Additional tests on polymer films were conducted by morphology and crystallinity tests with AFM and XRD. Chapter 4 and Chapter 5 show the screening of polymers as the semiconductor in OTFT sensors. P-type polymers and n-type polymers including commercially available ones and those synthesized by our group were employed in OTFT-sensors. P3HT and N2200 as typical p-type and n-type representatives have succeeded in the detection of PUT vapor as OTFT sensors. In addition, p-type polymers with FTPDO, DPP, indigo and bithiazole cores, n-type polymers with IBDF building block also showed sensing ability towards PUT vapor as OTFT sensors. Chapter 5 especially focuses on a series of 1,4-DPP polymers that exhibited high transistor performance as well as good air stability. As main factors that determine the performance of a sensor, operational temperature, stability, response and recovery time, sensitivity and selectivity of these DPP-polymer sensors showed very promising potential in PUT vapor detection. Food spoilage detection was realized with three types of DPP-sensors to detect vapors emitted by food samples. Mechanism of DPP-sensors to detect PUT vapor was studied by responses of the sensor, IV characteristics of the device, and morphology/crystallinity of the polymer. Combined with chemical properties of DPP-polymers and putrescine molecules, it was proposed that the trapping effect of lone pairs of electrons on putrescine molecules would cause the responses of DPP-OTFT sensors. Mobility dropping, drain-source current decrease and negative shift of VTH were observed with DPP-sensors by this trapping effect with the diffused PUT in the active channel. Future steps are expected based on this study. Better sensing ability can be achieved with the improvement on both transistors quality and polymers properties. More accurate relationships between sensors responses and PUT vapor concentrations can be built by optimizing gas sensing process. Spoilage detection of food products with OTFT sensors can be improved for more precise analysis with assistance of liquid chromatography (LC) and gas chromatography (GC). The ultimate goal of this study is to manufacture smart labels or tags with OTFT-sensors to attach on food packages, by connecting to smartphones or computers, fulfilling a real-time, in-situ detection of PUT vapor with ideal accuracy.

Download or read book Gas Detection with Floating Gate Field Effect Transistor written by R. Wahyu Widanarto and published by Cuvillier Verlag. This book was released on 2007 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Gas Sensors Using Organic Thin Films at Room Temperature written by N. E. Agbor and published by . This book was released on 1993 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Photo induced Room temperature Gas Sensing with A IGZO Based Thin film Transistors Fabricated on Flexible Plastic Foil written by Stefan Knobelspies and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Environmental Gas Sensing with High Surface Area Nanomaterials on a Low power Microfabricated Heater Platform written by Anna Claire Harley-Trochimczyk and published by . This book was released on 2016 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gas sensors can provide information about the presence of dangerous gases in industrial and residential sites, allowing for improved environmental protection and human health and safety. In order to enable ubiquitous wireless monitoring of combustible and toxic gases, sensor elements with low power consumption are required. Two common types of gas sensors, namely calorimetric and conductometric sensors, rely on heated sensor elements to activate the appropriate reactions with the gas of interest, resulting in high power requirements to maintain the necessary operating temperatures. Miniaturized gas sensors made with microfabricated heater platforms and nanoscale sensing materials can lead to low power sensor elements with high performance. The minimization of the power consumption cannot be at the expense of the sensor’s ability to detect dangerous combustible and toxic gases. The sensing performance is impacted by the properties of both the microheater and the sensing material, as well as the integration of the two elements, creating significant opportunity for research and development to improve the performance parameters, such as sensitivity, detectable concentration range, selectivity, response and recovery time, stability, size, manufacturability, and cost, as well as power consumption. The development approach described in the following thesis relies on an optimized microheater platform as well as novel sensing materials. The design, fabrication, and characterization of a low-power microheater platform is described, with polycrystalline silicon as the heater material for moderate temperature and polycrystalline silicon carbide for improved reliability at high temperature operation. A small, isolated heated area decreases the required power consumption and a closed membrane facilitates easier deposition of sensing materials. Sensing materials for combustible and toxic gas detection have been developed based on ultra high surface area aerogels. For combustible gas sensing, graphene or boron nitride aerogel acts as a scaffold for catalytic platinum or palladium nanoparticles. Bare graphene aerogel and graphene aerogel coated with single to few-layer molybdenum disulfide sheets are used for toxic gas detection. The microheater platform with fast response and recovery times provides opportunities for localized, in-situ synthesis of high surface area sensing materials. The use of the microheater platform for localized growth of a nanocrystalline tin oxide sensing film is described. The fast thermal response of the microheater leads to rapid heating of the precursor, creating a highly porous film that is proven beneficial for toxic gas sensing.

Download or read book Science and Technology of Chemiresistor Gas Sensors written by Dinesh K. Aswal and published by Nova Publishers. This book was released on 2007 with total page 398 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gas sensor technology has advanced remarkably during past few decades and has become one of the indispensable technologies for modern society. Varieties of gas sensors are commercially available and, using innovative ideas, efforts are being made to develop gas sensors of next generation having very small size with very low power consumption. The ultimate model for this is probably given by sensory organs of our own body, which are implanted finely and work well with a very modest amount of energy. In order to achieve this goal, it is essential that various aspects of gas sensors are seriously considered. These include understanding of gas sensing mechanisms, development of new materials and methods to synthesise them into selective sensors, innovations in nanostructured materials, measurement methods, microfabrication of sensors, exploring intelligent sensing system, etc. This book examines these issues pertaining to chemiresistive gas sensors.

Download or read book Graphene Materials written by Ashutosh Tiwari and published by John Wiley & Sons. This book was released on 2015-04-20 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: Graphene Materials: Fundamentals and EmergingApplications brings together innovative methodologies withresearch and development strategies to provide a detailedstate-of-the-art overview of the processing, properties, andtechnology developments of graphene materials and theirwide-ranging applications. The applications areas covered arebiosensing, energy storage, environmental monitoring, andhealth. The book discusses the various methods that have been developedfor the preparation and functionalization of single-layeredgraphene nanosheets. These form the essential building blocks forthe bottom-up architecture of various graphene materials becausethey possess unique physico-chemical properties such as largesurface areas, good conductivity and mechanical strength, highthermal stability and desirable flexibility. The electronicbehavior in graphene, such as dirac fermions obtained due to theinteraction with the ions of the lattice, has led to the discoveryof novel miracles like Klein tunneling in carbon-based solid statesystems and the so-called half-integer quantum Hall effect. Thecombination of these properties makes graphene a highly desirablematerial for applications. In particular, Graphene Materials: Fundamentals and EmergingApplications has chapters covering: • Graphene and related two-dimensional nanomaterials • Surface functionalization of graphene • Functional three-dimensional graphene networks • Covalent graphene-polymer nanocomposites • Magnesium matrix composites reinforced with graphenenanoplatelets • Graphene derivatives for energy storage • Graphene nanocomposite for high performance supercapacitors • Graphene nanocomposite-based bulk hetro-junction solar cells • Graphene bimetallic nanocatalysts foam for energy storage andbiosensing • Graphene nanocomposites-based for electrochemical sensors • Graphene electrodes for health and environmental monitoring

Download or read book Nanotechnology in Environmental Science 2 Volumes written by Chaudhery Mustansar Hussain and published by John Wiley & Sons. This book was released on 2018-05-29 with total page 898 pages. Available in PDF, EPUB and Kindle. Book excerpt: An overview of the current state of nanotechnology-based devices with applications in environmental science, focusing on nanomaterials and polymer nanocomposites. The handbook pays special attention to those nanotechnology-based approaches that promise easier, faster and cheaper processes in environmental monitoring and remediation. Furthermore, it presents up-to-date information on the economics, toxicity and regulations related to nanotechnology in detail. The book closes with a look at the role of nanotechnology for a green and sustainable future. With its coverage of existing and soon-to-be-realized devices this is an indispensable reference for both academic and corporate R&D.

Download or read book Advanced Nanomaterials for Inexpensive Gas Microsensors written by Eduard Llobet Valero and published by Elsevier. This book was released on 2019-11-13 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advanced Nanomaterials for Inexpensive Gas Microsensors: Synthesis, Integration and Applications presents full coverage in the area of gas sensing nanomaterials, from materials, transducers and applications, to the latest results and future direction. Experts present work on metal oxides, carbon-based and hybrid materials, fabrication and application. The book brings together three major themes, including synthesis, functionalization and the characterization of advanced nanomaterials, all emphasizing synthesis techniques that ease the integration of nanomaterials in transducers. Chapters encompass a wide spectrum of sensing technologies, including advanced nanomaterials (metal oxides, carbon materials and graphene) and organic molecular materials and atomic layers (MoS2). The book's authors examine the coupling of sensitive nanomaterials to different types of transducer elements and their applications, including direct growth and additive fabrication techniques as a way to obtain inexpensive gas microsensors, principal transduction schemes, and advanced operating methods. - Presents technological solutions and applications of gas sensors in varied areas of chemistry, physics, material science and engineering - Examines advanced operating methods (e.g., temperature modulation, self-heating, light-activated response, noise methods) to enhance stability, sensitivity, selectivity and reduce power consumption - Provides a critical review of current applications and their expected future evolution, demonstrating the most promising approaches and future expectations in the development of inexpensive gas micro- and nanosensors

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 602 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.

Download or read book Transparent Electronics written by Elvira Fortunato and published by . This book was released on with total page 337 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Semiconductor Gas Sensors written by Raivo Jaaniso and published by Woodhead Publishing. This book was released on 2019-09-24 with total page 512 pages. Available in PDF, EPUB and Kindle. Book excerpt: Semiconductor Gas Sensors, Second Edition, summarizes recent research on basic principles, new materials and emerging technologies in this essential field. Chapters cover the foundation of the underlying principles and sensing mechanisms of gas sensors, include expanded content on gas sensing characteristics, such as response, sensitivity and cross-sensitivity, present an overview of the nanomaterials utilized for gas sensing, and review the latest applications for semiconductor gas sensors, including environmental monitoring, indoor monitoring, medical applications, CMOS integration and chemical warfare agents. This second edition has been completely updated, thus ensuring it reflects current literature and the latest materials systems and applications. - Includes an overview of key applications, with new chapters on indoor monitoring and medical applications - Reviews developments in gas sensors and sensing methods, including an expanded section on gas sensor theory - Discusses the use of nanomaterials in gas sensing, with new chapters on single-layer graphene sensors, graphene oxide sensors, printed sensors, and much more

Download or read book Conducting Polymer Hybrids written by Vijay Kumar and published by Springer. This book was released on 2016-11-02 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a comprehensive survey about conducting polymers and their hybrids with different materials. It highlights the topics pertinent to research and development in academia and in the industry. The book thus discusses the preparation and characterization of these materials, as well as materials properties and their processing. The current challenges in the field are addressed, and an outline on new and even futuristic approaches is given. “Conducting Polymer Hybrids” is concerned with a fascinating class of materials with the promise for wide-ranging applications, including energy generation and storage, supercapacitors, electronics, display technologies, sensing, environmental and biomedical applications. The book covers a large variety of systems: one-, two-, and three-dimenstional composites and hybrids, mixed at micro- and nanolevel.

Download or read book Functional Nanomaterials written by Sabu Thomas and published by Springer Nature. This book was released on 2020-06-12 with total page 467 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a comprehensive overview of the current state-of-art in oxide nanostructures, carbon nanostructures and 2D materials fabrication. It covers mimicking of sensing mechanisms and applications in gas sensors. It focuses on gas sensors based on functional nanostructured materials, especially related to issues of sensitivity, selectivity, and temperature dependency for sensors. It covers synthesis, properties, and current gas sensing tools and discusses the necessity for miniaturized sensors. This book will be of use to senior undergraduate and graduate students, professionals, and researchers in the field of solid-state physics, materials science, surface science and chemical engineering.