SCIENCE AND TECHNOLOGY OF CHEMIRESISTOR GAS SENSORS -- SCIENCE AND TECHNOLOGY OF CHEMIRESISTOR GAS SENSORS -- LIBRARY OF CONGRESS CATALOGING-IN-PUBLICATION DATA -- CONTENTS -- PREFACE -- Chapter 1: OVERVIEW OF GAS SENSOR TECHNOLOGY -- ABSTRACT -- 1. BACKGROUND OF GAS SENSOR TECHNOLOGY -- 2. TYPES AND PRINCIPLES OF GAS SENSORS -- 2.1. Types of Gas Sensors -- 2.2. Receptors and Transducers - Construction Principles -- 2.3. Modes of Gas Sensing -- Equilibrium Mode -- Steady State Mode -- Complete Reaction Mode -- Accumulation Mode -- 3. BIRTH AND GROWTH OF GAS SENSOR TECHNOLOGY -- 3.1. Brief History -- 3.2. Mature Markets -- 3.3. Emerging Markets -- Air Quality Sensor -- Auto-damper sensor -- Gas Sensor -combined Fire Alarm -- Quality-discerning Odor Analyzer -- CO2 Sensor -- NOx Sensors -- 3.4. Challenging Markets -- Onboard Car-Emission Sensors -- Environmental Monitoring -- Process Gas Monitoring -- Wearable Sensors and Ubiquitous Sensors -- 4. FUNDAMENTAL ASPECTS OF SEMICONDUCTOR GAS SENSORS -- 4.1. Three Basic Factors -- 4.2. Higher Order Structure Favorable for High Sensitivity -- 4.3. Sensor Design to Promote Selectivity -- 5. PROPOSALS FOR NEXT GENERATION TECHNOLOGY -- (1) Challenge Ultimately Miniaturized Gas Sensors -- (2) Pay More Attention to Materials Processing and Materials Science -- (3) Explore Intelligent Sensing Systems -- (4) Seek Collaboration with Experts of Different Disciplines -- REFERENCES -- Chapter 2: CHEMIRESISTOR GAS SENSORS: MATERIALS, MECHANISMS AND FABRICATION -- ABSTRACT -- 1. INTRODUCTION -- 2. CHEMIRESISTIVE SENSOR -- 2.1. Basic Characteristics -- 2.2. Determination of Sensing Parameters -- 3. CHEMIRESISTIVE SENSOR MATERIALS -- 3.1. Semiconductor Metal-oxides -- (a) Materials and Analyte Gases -- (b) Problems Associated with Metal-oxide Sensors -- 3.2. Non-oxide Materials -- 4. TIN OXIDE SENSOR.

4.1. Physical Properties -- 4.2. Gas Sensing Properties of Pure SnO2 -- 4.3. Influence of Additives on Sensing Mechanism of SnO2 -- (a) Catalytic Effect -- (b) Spill-over Effect -- c) Fermi Energy Control -- 5. SENSOR FABRICATION -- 5.1. Pellet-based Sensors -- 5.2. Meso-porous Sensor -- 5.3. Thick Film Based Sensors -- 5.4. Thin Film Based Sensors -- (a) Physical Vapor Deposition -- (b) Chemical Vapor Deposition -- 6. SELECTIVE TIN OXIDE SENSORS -- 6.1. H2S Gas Sensor -- (a) Sensor Fabrication -- (b) Sensor Characteristics -- (c) Sensing Mechanism -- (d) Impedance Spectroscopy -- 6.2. NH3 Sensor -- 6.3. NO Sensor -- 6.4. H2 Sensor -- 7. FACTORS DETERMINING SENSING PROPERTIES -- 7.1. Geometrical Factors -- (a) Grain Size Effect -- (b) Crystallographic Plane Effect -- (c) Agglomeration of Grains and Porosity Effect -- 7.2. Physico-chemical Properties -- 8. GAS SENSORS ON MICROHOTPLATES -- CONCLUSIONS -- ACKNOWLEDGEMENTS -- REFERENCES -- Chapter 3: ONE-ELECTRODE SEMICONDUCTOR GAS SENSORS -- ABSTRACT -- 1. INTRODUCTION -- 2. DESIGN FEATURES OF ONE-ELECTRODE METAL OXIDE GAS SENSORS AND THEIR PRINCIPLE OF OPERATION -- 2.1. Parameters of One-electrode Gas Sensors and Their OperatingPrinciples -- 2.2. Selection of Gas Sensing Materials -- 2.3. Comparison of One-electrode Semiconductor Gas Sensor and Pellistors -- 2.3.1. Pellistor Sensors -- 2.3.2. Comparison of One-electrode Semiconductor Sensors and Pellistors -- 3. TYPES OF ONE-ELECTRODE SEMICONDUCTOR GAS SENSORS -- 3.1. Ceramic Bead Type One-electrode Gas Sensors -- 3.2. Planar One-electrode Semiconductor Sensors -- 3.2.1. Thick Film Sensors -- 3.2.2. Thin Film Sensors -- 4. ADVANTAGES AND DISADVANTAGES OF ONE-ELECTRODE METAL OXIDE GAS SENSORS -- 5. OPTIMIZATION OF ONE-ELECTRODE SEMICONDUCTOR GAS SENSORS -- 5.1. Optimization of Gas Response through Chemical Modification of Metal Oxide Phase.

5.2. Effect of Doping on Electrophysical Properties and Sensor Response of In2O3-based One-electrode Sensors -- 5.3. Effect of Doping on Response Time and Sensitivity of In2O3 Sensors -- 5.4. Influence of Humidity on the Gas Response of In2O3-based One-electrode Gas Sensors -- 5.5. Structural Properties of In2O3-based Doped Ceramics Used for Sensor Fabriation -- 5.5.1. Raman Scattering Spectroscopy Studies of In2O3-doped Ceramics -- 5.5.2. Model of the Grain Structure of In2O3 Doped Ceramics -- 6. MARKET OF ONE-ELECTRODE SEMICONDUCTOR GAS SENSORS -- 6.1. One-electrode Gas Sensors Fabricated by "INNOVATSENSOR Ltd" -- 6.2. Sensors of Henan Hanwei Electronics Co Ltd. -- 6.3. One-electrode Gas Sensors of New Cosmos Electric Co -- 7. PROBLEMS AND PROSPECTUS OF ONE-ELECTRODE SEMICONDUCTOR GAS SENSORS -- ACKNOWLEDGEMENTS -- REFERENCES -- Chapter 4: NANOSTRUCTURED METAL OXIDES AND THEIR HYBRIDS FOR GAS SENSING APPLICATIONS -- ABSTRACT -- 1. INTRODUCTION -- 2. SIZE MATTERS AND THEREFORE 'NANO' MATTERS FOR GAS SENSING -- 3. NANOSTRUCTURED METAL OXIDES -- 3.1. Basic Mechanisms of Gas Sensing in Semiconductor -- 3.2. Surface states and Double Layers -- 3.3. N-P Type and P-N Type Transitions in Semiconductor Gas Sensors -- 4. IMPORTANCE OF 'NANO' -- 5. FABRICATION OF NANOSTRUCTURED METAL OXIDES -- 5.1. Conventional Methods -- 5.1.1. Thin Film Technologies -- 5.1.2. Thick Film Technologies -- 5.2. Unconventional Nanostructures -- 6. CASE STUDIES OF 1D AND 2D NANOSTRUCTURED SEMICONDUCTOR METAL OXIDES -- 6.1. Basic Gas Sensing Mechanism in 1D Nanostructures -- 6.2. Use of Catalysts -- 6.3. 1D and 2D Metal Oxides -- 6.3.1. Zinc Oxide -- 6.3.2. Tin Oxide Nanostructures and their Applicability in Sensing -- 6.3.3. Indium Oxide -- 6.3.4. Tungsten Oxide -- 6.3.5. Molybdenum Oxide -- 6.3.6. V2O5 -- 6.4. Future Challenges -- 7. SUMMARY -- REFERENCES.

Chapter 5: THE DYNAMIC MEASUREMENTS OF SNO2 GAS SENSORS AND THEIR APPLICATIONS -- ABSTRACT -- 1. INTRODUCTION -- 2. EXPERIMENTS -- 2.1. Fabrication of Tin Oxide Sensors -- 2.2. Experimental Set-up -- 2.3. Static and Dynamic Measurements -- 2.3.1. Differences between Static and Dynamic Measurements -- 2.3.2. Static Measurements -- 2.3.3. Dynamic Measurements -- 2.3.4. Necessary Conditions for Dynamic Measurements -- 3. INFLUENCE FACTORS IN THE MEASUREMENT PROCESS -- 3.1. Effect of the Duty Ratios at an Applied Potential of 7V -- 3.2. Effect of Modulation Waveform -- 3.3. Effect of the Modulation Temperature -- 3.3.1. Temperature Variation under Static Measurements -- 3.3.2. Temperature Curves under Different Duty Ratios -- 3.3.3. Temperature Curves under Different Applied Voltages -- 4. THEORETICAL MODEL AND SIGNAL PROCESSING -- 4.1. Theoretical Model for Conductance -- 4.2. Feature Extraction -- 4.2.1. Estimation of the Model Parameters by Curve Fitting -- 4.2.2. Fourier Transform (FT) -- 4.2.3. Wavelet Transform (WT) -- 4.3. Qualitative Analysis -- 4.4. Quantitative Analysis -- 5. APPLICATIONS IN DETECTING HAZARD GASES -- 5.1. Application in Detecting Liquefied Petroleum Gas (LPG) -- 5.1.1. The Dynamic Measurement of Liquefied Petroleum Gas (LPG) -- 5.1.2. FFT -- 5.2. Application in Detecting CO and CH4 -- 5.2.1. The Dynamic Response to CO and CH4 -- 5.2.2. Feature Extraction -- 5.2.3. Qualitative Analysis -- 5.2.4. Quantitative Analysis -- 5.3. Application in Detecting Pesticide Residue -- 5.3.1. Comparative Experiments between Static and Dynamic Response to Pesticides -- 5.3.2. The Dynamic Response to Pesticides under Different Concentrations -- 5.4. SPME/SnO2 Gas Sensor for the Detection of Organophosphorus Pesticides -- 5.4.1. The Dynamic Response to Pesticides Based on the SPME/SnO2 Gas Sensor -- 5.4.2. Data Evaluation and Feature Extraction.

6. SUMMARY -- ACKNOWLEDGEMENTS -- REFERENCES -- Chapter 6: RESISTIVE OXYGEN SENSORS -- ABSTRACT -- 1. INTRODUCTION -- 2. OXYGEN SENSORS FOR AUTOMOTIVE EMISSION CONTROL -- 3. DEFECT CHEMISTRY OF METAL-OXIDES -- 3.1. Undoped and Lightly-doped Systems (Dilute Solutions) -- 3.2. Heavily-doped Systems (Concentrated Solutions) -- 3.3. Solid-solution Systems -- 3.4. The Defect Chemistry of SrTi1-xFexO3-y -- 4. TEMPERATURE DEPENDENCE -- 5. KINETICS -- 6. STABILITY -- 7. SUMMARY -- ACKNOWLEDGMENTS -- REFERENCES -- Chapter 7: TELLURIUM THIN FILMS BASED GAS SENSOR -- ABSTRACT -- 1. INTRODUCTION -- 2. BONDING AND CRYSTAL STRUCTURE -- 2.1. Bonding -- 2.2. Crystal Structure -- 3. FABRICATION OF TE SENSORS -- 3.1. Thin Film Deposition -- 3.2. Fabrication of Sensor Device -- 4. MICROSTRUCTURE AND ELECTRICAL PROPERTIES OF TE FILMS -- 4.1. Effect of Substrate Temperature -- 4.2. Effect of Post Deposition Annealing -- 4.3. Effect of Substrate Microstructure -- 4.4. Effect of Film Thickness and Deposition Rate -- 5. SENSITIVITY OF TE FILMS TO GASES -- 5.1. Effect of Operating Temperature on Response -- 5.2. Effect of Gas Concentration on Sensitivity -- 5.3. Effect of Deposition Parameters on Sensor Characteristics -- 5.3.1. Deposition Temperature -- 5.3.2. Substrate Microstructure -- 5.3.3. Post Deposition Annealing -- 5.3.4. Film Thickness and Deposition Rate -- 6. MECHANISM OF GAS-FILM INTERACTION -- 6.1. Raman Spectroscopy -- 6.2. X-ray Photoelectron Spectroscopy -- 6.3. Impedance Spectroscopy -- 6.4. Band Model for Gas-Te Film Interaction -- 7. LONG-TERM STABILITY AND SELECTIVITY -- 8. CONCLUSIONS -- REFERENCES -- Chapter 8: VIBRATING CAPACITOR METHOD IN THE DEVELOPMENT OF SEMICONDUCTOR GAS SENSORS -- ABSTRACT -- 8.1. INTRODUCTION -- 8.2. THE VIBRATING CAPACITOR -- 8.2.1. Principle of the Operation -- 8.2.2. Practical Realisation of the Vibrating Capacitor System.

8.2.3. The Kelvin Force Microscopy.