Solid State Gas Sensors - Industrial Application (eBook)

Solid State Gas Sensors - Industrial Application 3
Aims and Scope 5
Preface 7
Stakeholders in Gas Sensing 7
Development of a New Gas Sensing Technology 7
Implementation of a New Gas Sensing Application 8
Better Communication Amongst the Stakeholders Is Needed 9
Contents 11
Part I: Requirements on Sensing 
13 
Future Building Gas Sensing Applications 14
1 Vision of Sustainable Built Environment 15
2 The Role of Sensing Applications in Next Generation Building 16
3 Sensing Need for Specific Applications 20
3.1 Comfort 20
3.2 Health 20
3.3 Energy Management Applications 20
3.4 Security 21
3.5 Life Safety 21
4 Building That Knows You and Your Physical Environment 22
5 Carbon and Sustainability Footprint 22
6 Conclusion 23
References 23
Requirements for Gas Sensors in Automotive Air Quality Applications 24
1 Introduction 25
2 Technical Specification 26
2.1 Functional Requirements 26
2.2 Sensor Signal Conditioning 28
2.2.1 Conditioning of an Analog Output Signal 28
2.2.2 Conditioning of a Pulse-Width Modulated Output Signal 30
2.2.3 Conditioning of an LIN Output Signal 31
3 Automotive Suitability 33
3.1 Electrical Requirements 33
3.2 EMC Qualification 35
3.3 Mechanical, Climatic, and Lifetime Qualification 36
3.4 Chemical Qualification 40
4 Implementation in the Automotive Air Conditioning System 40
4.1 Detection of the Air Quality in the Vehicle Exterior 40
4.2 Detection of the Air Quality Inside the Vehicle 42
5 Conclusion 44
References 44
Automotive Hydrogen Sensors: Current and Future Requirements 45
1 Introduction 45
2 Hydrogen Sensor Modules in Chevrolet Equinox Fuel Cell 46
2.1 Ambient Hydrogen Concentration Sensor Module (AHS) 46
2.2 Exhaust Hydrogen Concentration Sensor Module (EHS) 46
3 Future Requirements 47
Requirements for Fire Detectors 49
1 Theory 50
2 Applications 51
2.1 Introduction 51
2.2 Proven Technologies 52
2.2.1 Ionization Sensors 52
2.2.2 Optical Smoke Sensors 52
2.2.3 Heat Sensors 54
2.2.4 Interim Results 54
2.2.5 Gas Detection 54
2.2.6 Electrochemical Cell Based 55
2.2.7 Semiconductor Based 55
2.3 Perspective to the Future 56
3 Standardization 56
3.1 Introduction 56
3.2 Standardization at ISO-Level 57
3.3 Standardization at CEN-Level 57
3.4 Other Regulation Bodies 59
References 60
Part II: Sensor Principles 
61 
The Power of Nanomaterial Approaches in Gas Sensors 62
1 Introduction 63
2 Deposition Techniques and Growth Mechanisms 64
2.1 Vapor Phase Growth 65
2.2 Solution Phase Growth 66
2.3 Devices Fabrication 68
3 Electrical Properties 69
4 Working Principles 71
5 DC Conductometric Gas Sensors 72
5.1 Single Nanowire Devices 72
5.2 Multiple Nanowire Devices 75
6 SNT-Based Sensors 78
7 PL-Based Sensors 80
7.1 SnO2 81
7.2 ZnO 82
8 Conclusions and Future Challenges 83
References 84
Theory and Application of Suspended Gate FET Gas Sensors 88
1 Introduction 91
2 Principles of Operation 93
2.1 Gas Adsorption on Solids 93
2.2 The Work Function 94
2.3 Work Function Change Caused by Gas Adsorption 95
3 Transducer Concepts 97
3.1 The Lundström FET 97
3.2 The Suspended Gate FET 98
3.3 The Hybrid Suspended Gate FET 99
3.4 The Floating Gate FET (FG-FET) 100
4 The FET-Based Hydrogen Sensor 101
4.1 Requirements for Automotive Applications 101
4.2 The FG-FET Hydrogen Sensor 102
4.3 The Catalytic Ignition 103
5 The Temperature-Controlled Phase Transition FET (TPT-FET) 108
5.1 Fabrication and Embedding of the Sensitive Layer 108
5.2 Results and Discussion 109
5.3 Understanding the Phase Transition 110
5.4 Temperature Dependence of the Phase Transition 111
5.5 Modeling of the Temperature Dependence 112
5.6 The Temperature-Controlled Mode 112
5.7 Response Time 114
5.8 Hydrogen Dual Sensor: Lundström and FG-FET on One Chip 116
6 GasFET Concept for High Temperature Operation 117
6.1 Requirements for High Temperature Operation of Silicon-Based MOS-FETs 117
6.2 Device Design of the FG-FET for High Temperature Operation (HT-FG-FET) 117
6.2.1 Highly Doped Vertical MOS-FET 117
6.2.2 Fabrication on SOI Substrates 118
6.3 High Temperature Measurements 118
6.4 Conclusion 119
References 120
Chromium Titanium Oxide-Based Ammonia Sensors 122
1 Introduction 123
1.1 Piggery 124
1.2 Leakage Detecting in Refrigeration Systems 124
1.3 Selective Catalytic Reduction 124
2 State of the Art 125
2.1 Electrochemical Cells for Ammonia Detection 125
2.2 Other Solid-State-Based Ammonia Sensors 126
2.3 Polymer-Based Ammonia Sensors 127
2.4 Optical and Colorimetric Ammonia Sensors 128
3 Chromium Titanium Oxide-Based Resistive Sensors 129
3.1 Introduction 129
3.2 Chromium Titanium Oxide 130
3.3 Fabrication Technologies 131
3.3.1 Screen Printed CTO sensors 131
3.3.2 Inkjet Printed CTO sensors 131
3.3.3 Atmospheric Pressure Chemical Vapor Deposition of CTO 133
3.3.4 Sol-Gel Process 134
3.3.5 Thin-Film Sensors 134
3.4 Gas sensing Behavior 135
4 Chromium Titanium Oxide in Work Function Type Sensors 138
4.1 Introduction 138
4.2 Experimental 138
4.2.1 Kelvin Probe 138
4.2.2 Suspended Gate Field Effect Transistor Using CTO as Sensitive Layer 139
4.2.3 Gas Measurements 140
4.3 Results and Discussion 140
References 142
Part III: Applications 
145 
Combined Humidity- and Temperature Sensor 146
1 Introduction 147
1.1 Relative Humidity 147
1.2 Absolute Humidity 148
1.3 Dew Point 148
2 Temperature- and Humidity Sensor 149
2.1 Platinum-Temperature Sensor 149
2.2 Capacitive Humidity Sensors 150
3 Humidity Sensors in Applications 152
4 Combined Sensor: Humidity+Temperature Sensor/Heater 153
5 Optimized Technology on Customer Request 155
References 156
Gas Sensor Investigations in Characterizing Textile Fibres 157
1 Introduction 158
2 Experimental Conditions and Results 158
2.1 Samples and Apparatus 158
2.2 Sensor Elements 160
3 Discussion 162
3.1 Thermal Decomposition of PET 162
3.2 Thermal Decomposition of Finish 169
3.3 Sensor Response 172
3.3.1 Strong Sensor Response to Decomposition Products of Finish 173
3.3.2 Weak Sensor Response to Decomposition Products of PET Fibres 174
4 Conclusion 176
References 177
New Approaches for Exhaust Gas Sensing 178
1 Introduction 179
2 Sensors for Lean NOx Traps 180
2.1 NOx Sensors 181
2.2 Sensors for Directly Determining the Loading Degree of an LNT 181
3 Sensors for NH3-SCR-deNOx 183
3.1 NH3 Sensors 183
3.2 Sensors for Directly Determining the Ammonia Storage Degree of an SCR Catalyst 186
4 Radio Frequency-Based Catalyst Gauging 187
5 Conclusion 190
References 190
Technology and Application Opportunities for SiC-FET Gas Sensors 194
1 Introduction 195
2 Detection Mechanism of FET Gas Sensors 197
3 Processing and Electrical Operation of FET Devices 201
4 Tailor-Made Sensing of FET Devices 203
5 Results 203
5.1 Applications at an Ambient Temperature Above 500C 204
5.1.1 Syngas Control in a Power Plant 204
5.1.2 Cylinder-Specific Monitoring 204
5.1.3 Cold Start and EGR Sensor 206
5.2 Applications at an Ambient Temperature Below 500C 207
5.2.1 Engines, Gas Turbines, and Boiler Plants 207
5.2.2 Aerospace Applications and Fire Alarms 207
5.2.3 NH3 Sensor for SCR Control 208
5.2.4 NH3 Sensor for SNCR Control 209
5.3 Domestic Boiler Control, Commercialization 209
6 Future Trends and Development in SiC-FET Sensors 212
6.1 Improved Contact Material to SiC 212
6.2 Packaging 213
6.3 3C SiC 213
6.4 WBG Materials for FETs 214
7 Conclusions 214
References 215
Development of Planar Potentiometric Gas Sensors for Automotive Exhaust Application 220
1 Introduction 221
1.1 State of the Art 221
1.2 Research at St-Etienne and Objectives of the Chapter 225
2 Experimental 226
2.1 Sensors Preparation 226
2.2 Sensor Bench Test 227
3 Results with beta-Alumina Sensors 227
3.1 Typical Sensor Responses to Oxidant and Reducing Gases on Laboratory Bench 227
3.2 Development of Sensors for the Engine Bench Tests 229
3.3 Protective Layer for the Sensing Element 230
3.4 Tests of beta-Alumina Sensors on Motor Bench 232
4 Comparison of beta-Alumina and YSZ Sensor Performances 235
4.1 General Behaviour 235
4.2 CO, HC and NO2 Performances 236
4.3 NH3 Responses 236
4.4 Sensor Ageing 239
5 Prospective Studies 240
5.1 Electrodes Materials 240
5.2 Amperometric Mode: Electrode Polarisation 240
5.3 Catalytic Filter for Selectivity Modification 241
6 Discussion and Modelling 242
6.1 Limitation of the Mixed Potential Model 242
6.2 Complementary Experiments with Au/beta-Alumina/Pt Device 247
6.2.1 Vibrating Capacitor Method (PUP) 248
6.2.2 Impedance Spectroscopy Technique 249
6.2.3 Electrodes Sizes 250
6.3 Capacitive Model 251
7 Conclusion 255
References 256
Atmospheric Humidity Measurements Using Gas Sensors 260
1 Introduction 261
1.1 Upper Air Observations 261
1.2 Weather Prediction and Environmental Monitoring 262
1.3 Aviation and Ballistic Applications 263
1.4 Climate Change and Atmospheric Research Studies 263
2 Historical and Present-Day Upper Air Humidity Sensors 264
2.1 Standard Humidity Sensors on Operational Radiosondes 264
2.2 Research and Reference Humidity Sensors 264
2.3 Fluorescence Hygrometers for Stratospheric H2O Measurements 265
3 Thin-Film Capacitive Sensors 265
3.1 Principle of Operation 265
3.2 Upper Air Applications 266
4 Intercomparisons and Reference Upper Air Observations 267
4.1 International Radiosonde Intercomparisons 267
4.2 Reference Upper Air Network 268
5 Conclusions 268
References 269
Concluding Remarks 270
Index 271