Firsthand insights into the current and future technology and large-scale applications of color- and opacity-changing optical materials
Chromogenics delivers a comprehensive overview of the industry-relevant scientific background of chromogenics and provides details on successful manufacturing techniques for the scalable fabrication of products, enabling readers to apply chromogenic materials in billion-dollar market segments such as the car industry (rear-view mirrors) and building and construction industries (self-tinting windows), as well as for individual end-user products such as sunglasses.
This work includes contributions from developers of chromogenic products from leading companies and industry-near research institutions such as Fraunhofer, Merck, Pleotint, and Gentex, Chromogenics explores topics including:
- Electrochromics (both inorganic and polymeric), thermochromics, and suspended particle devices (SPD)
- Encapsulated pigment devices, specific liquid crystals, and polymer dispersed liquid crystals (PDLC)
- Vacuum web coaters and their large-area coatings, transparent electronic conductors, sputter coating processes, and pyrolytic doped tin oxide
- Commercial technologies including pyrolytic deposition, magnetron sputtering, slot die coating, and doctor blade coating
- Products such as switchable self-dimming mirrors and switchable glazing for glare reduction, solar energy control, and privacy glazing
Presenting state-of-the-art research in the field along with future outlooks, Chromogenics is an essential reference on the subject for materials scientists, physical chemists, applied physicists, and engineering scientists in industry.
Table of Contents:
List of Contributors xiii
Preface xv
Part I Technologies 1
1a Overview of Chromogenics 3
Carl M. Lampert
Nomenclature 3
1a.1 Introduction 5
1a.2 The Dynamic Glass Market 7
1a.2.1 Automotive 8
1a.2.2 Eyewear 9
1a.2.3 Architectural 10
1a.2.4 Aerospace 12
1a.2.5 Information Display 12
1a.3 Families of Chromogenic Materials 13
1a.3.1 Chromogenics Switching by Collective Physical Movement 14
1a.3.1.1 Electromechanical 17
1a.3.1.2 Mechanochromism 19
1a.3.1.3 Magnetochromics and Magnetoionics 20
1a.3.1.4 Electrokinetics 21
1a.3.1.5 Dispersed Liquid Crystals (PDLC and NCAP) 22
1a.3.1.6 Suspended Particles 26
1a.3.2 The Chemichromic and Electrochemichromic Families 28
1a.3.2.1 Gasochromic 30
1a.3.2.2 Halochromism 34
1a.3.2.3 Solvatochromism 35
1a.3.2.4 Hydrochromism 35
1a.3.2.5 Electrochemichromic 35
1a.4 Chromogenic Switching by Discrete Movement of Ions, Atoms, and Molecules 36
1a.4.1 Electrochromics 37
1a.4.1.1 Inorganic Electrochromics 38
1a.4.1.2 Organic and Polymer Electrochromics 41
1a.4.2 Light-Induced Switching – Photochromics 42
1a.4.3 Thermal-Induced Switching – Thermochromic and Thermotropics 45
1a.4.3.1 Thermal-Induced Switching – Ligand Exchange Thermochromic (LETC) 46
1a.4.3.2 Thermal-Induced Switching – Thermotropics 48
1a.5 Multiband Switching Windows and Surfaces 49
1a.6 Running a Chromogenics Business 50
1a.6.1 Organizational Viewpoint 51
1a.6.2 Materials Viewpoint – Chromogenics 51
1a.6.3 Materials Viewpoint – Electrochromics 52
1a.6.4 Manufacturing Viewpoint 52
1a.6.5 Marketing Perspective 53
1a.7 Additional Information about Chromogenics 53
Acknowledgments 54
References 54
1b Introduction to Glazing Design and Measurements 69
Carl M. Lampert
Nomenclature 69
1b.1 Common Metrics for Glazing 71
1b.2 Solar Radiation and the Earth’s Atmosphere 72
1b.2.1 Clearness Index 74
1b.2.2 Daylighting 74
1b.3 Transmittance, Reflectance, and Absorptance Measurements 75
1b.3.1 Solar Transmittance 75
1b.3.2 Luminous, Visible Transmittance, and Visible Light Transmittance (VLT) 75
1b.3.3 Absorbance or Optical Density Measurement 77
1b.3.4 Haze and Scattering Measurements 78
1b.4 Color Measurements 80
1b.5 Thermal Emissivity and Emittance 82
1b.5.1 Low-e Coatings and Transparent Conductors used in Insulated Glass Units (IGUs) 83
1b.6 Design of an IGU Window System 86
1b.7 Energy Flow Mechanisms in Glazing Fenestration 87
1b.7.1 Conductive Heat Transport 88
1b.7.2 Convective Heat Transport 88
1b.7.3 Radiative Heat Transport 88
1b.8 Parameters Commonly Used to Characterize Window Glazing 89
1b.8.1 U-Factor 89
1b.8.2 Solar Heat Gain Coefficient (SHGC) 90
1b.8.3 Solar Factor (g-Value) or Total Solar Energy Transmittance (TSET) 91
1b.8.4 Total Solar Transmittance 91
1b.8.5 Instantaneous Heat Flow in a Whole Glazing 91
Acknowledgments 92
References 92
2 Electrochromics 97
Carl M. Lampert, Anoop Agrawal, and Junichi Nagai
Nomenclature 97
2.1 Introduction to the Field of Electrochromics 100
2.2 Electrochromic Materials 101
2.2.1 Coloration Efficiency 105
2.3 Electrochromic Device Design 106
2.3.1 Transparent Conductors 110
2.3.2 Electrochromic Device Switching Time 111
2.4 Self-Dimming Automotive Rearview Mirrors 112
2.5 Early Development of Electrochromic Automotive Sunroofs 116
2.6 Early Electrochromic Windows Developed at Asahi Glass Company 118
2.7 Designing Materials Systems for Electrochromic Glazing 120
2.8 Dynamic Building Windows 123
2.9 Commercial Electrochromic Windows 124
2.9.1 Window Performance Parameters 125
2.9.2 Electrochromic Glazing Examples 127
2.10 Multiband Switching for Glazing 134
2.10.1 Localized Surface Plasma Resonance (LSPR) 134
2.10.2 Early Commercial Development of LSPR Nanocrystals for Dual-Band Switchable Glazing 136
2.10.3 Research in Dual-Band Electrochromics 136
2.11 Electrochromic Windows for Aircraft 139
2.12 Electrochromic Eyewear 142
2.13 Electrochromic Information Displays 144
2.14 Electrochromic Gradient Filter 146
2.15 Dynamic Thermal Emittance Electrochromics for Spacecraft and Spacesuits 149
2.16 Other Electrochromic Devices: Photoelectrochromic and Photovoltaic-Electrochromic 151
Acknowledgments 151
References 151
3 Trends in Organic Electrochromic Materials and Their Applications 173
Melepurath Deepa and Anoop Agrawal
Nomenclature 173
3.1 Introduction to Organic Electrochromics 174
3.2 Organic EC Materials and Device Architectures 176
3.3 Electrochromic Supercapacitors (ESCs) with at Least One Transparent State 182
3.4 Integration of PV and ECD−Photoelectrochromic Device 187
References 191
4 Polymeric Electrochromics 195
Marco Schott and Uwe Posset
Nomenclature 195
4.1 Introduction 196
4.2 Electrochromic Polymers 196
4.2.1 Conjugated Polymers 196
4.2.2 Metal Coordination Polymers 204
4.3 Device Manufacturing 206
4.4 Industrial Applications of Polymeric Electrochromic Devices 213
4.5 Conclusion and Outlook 216
References 218
5 Evolution of Industrial Polymer Dispersed Liquid Crystal (PDLC) Technology in Europe: A Review of Research, Development, Manufacturing, and Potential Emerging Technologies 229
H. Hakemi
Nomenclature 229
5.1 Introduction to PDLC Technology 229
5.2 The Original PDLC Inventions 232
5.2.1 Micro-Emulsion (ME) Invention 233
5.2.2 Phase Separation (PS) Invention 233
5.2.2.1 Polymer Induced Phase Separation (PIPS) 233
5.2.2.2 Solvent Induced Phase Separation (SIPS) 233
5.2.2.3 Thermal Induced Phase Separation (TIPS) 233
5.3 Manufacturing Methods of PDLC Film 235
5.4 Historical Evolution of Industrial PDLC Technology 236
5.4.1 The Early Period (<1995) 237
5.4.2 The Setback Period (1995–2005) 238
5.4.3 The Revival Period (>2005) 238
5.5 PDLC Industrial Development in Italy 240
5.5.1 SNR (Italy) PDLC License 240
5.5.2 SNR Industrial R&D Program 242
5.5.3 SNR Production Program 243
5.5.3.1 Dry/Coating & Lamination Technique 244
5.5.3.2 Wet/Coating & Lamination Technique 244
5.5.4 SNR Intellectual Property 246
5.6 Important Industrial Development Issues 247
5.6.1 The Significance of Scale 247
5.6.2 The Significance of Time 247
5.7 Industrial Development of PDLC in Europe 247
5.7.1 Innoptec S.p.A. (Italy) 248
5.7.2 Dream Glass S.L. (Spain) 248
5.7.3 Gauzy Ltd. (Israel) 248
5.8 Potential Emerging Industrial PDLC Technologies 249
5.8.1 Direct PDLC Glazing 249
5.8.2 Bistable PDLC 250
5.8.3 Solar-Control PDLC 251
5.8.4 Dynamic PDLC Signage 251
5.9 The PDLC Market Situation 253
References 253
6 Suspended Particle Devices 261
Philippe Lemarchand and Brian Norton
Nomenclature 261
6.1 Introduction 262
6.2 Materials 264
6.3 Manufacture and Commercial Specifications 266
6.3.1 Switching Duration 267
6.3.2 Spectral Transmittance 272
6.4 Applications in the Built Environment 276
6.5 Accelerated Testing 279
6.6 Conclusion 284
Acknowledgment 287
References 287
7 Inorganic Thermochromics and Photochromics 293
Lars Österlund, José Montero, and Gunnar A. Niklasson
Nomenclature 293
7.1 Introduction 294
7.2 Optical Properties 295
7.3 Thermochromic Coatings 297
7.3.1 Challenges for VO 2 -Based Films 299
7.3.2 Synthesis of VO 2 -Based Thermochromic Films 304
7.3.3 Synthesis of VO 2 -Based Nanoparticles and Nanocomposites 307
7.4 Photochromic Coatings 310
7.4.1 Silver Halides 312
7.4.2 Transition Metal Oxides 312
7.4.3 Rare-Earth Oxyhydrides 315
7.5 Thermochromic and Photochromic Smart Windows 318
7.5.1 Applications of Thermochromic and Photochromic Glazing 318
7.5.2 Performance Limits 322
7.6 Conclusions 324
References 325
8 Overview of Organic Thermochromic Materials 341
Gunnar A. Niklasson, José Montero, and Carl M. Lampert
Nomenclature 341
8.1 Introduction 342
8.2 Clear Organic Thermochromics 344
8.2.1 Ligand-Exchange, Metal–Organic Materials 344
8.2.2 Leuco Dyes in a Matrix 350
8.3 Thermotropic Materials 353
8.3.1 Hydrogels 354
8.3.2 Polymer Blends 357
8.3.3 Ionogels 359
8.3.4 Casting Resins 360
8.3.5 Additional Materials 361
8.4 Discussion and Comparison 361
References 365
9 Other Chromogenic Technologies 371
Carl M. Lampert
Nomenclature 371
9.1 Introduction 372
9.2 E Ink – Encapsulated Electrophoretic Ink 373
9.3 eyrise® Liquid Crystal Glazing 379
9.4 ELSTAR Dynamics Electrophoretic Glazing 383
9.5 MEMS and Microshutter Materials 385
9.6 Optofluidics 388
9.7 Thermochromic Perovskites 390
Acknowledgments 391
References 392
Part II Manufacturing 395
10 Introduction to Manufacturing 397
Carl M. Lampert
Nomenclature 397
10.1 Manufacturing Introduction 398
10.2 The Glass Industry 398
10.3 Surface Cleaning 402
10.4 Flat Glass Sputter Coating 403
10.5 Vacuum Web Coating 406
10.5.1 Flexible Electrochromic Coating 406
10.5.2 Flexible Glass 407
10.6 Other Flat Glass Coating Processes 408
10.7 Slot-Die Coating 408
10.8 Wet-Chemical Sol–Gel Deposition 410
10.9 Atomic Layer Deposition (ALD) 413
10.9.1 Spatial ALD 413
10.10 Inkjet Deposition 415
10.11 Photonic Processing 417
10.12 Busbars and Electrical Connections 418
Acknowledgments 418
References 419
11 Sputter Coating Processes and Industrial Approaches 427
Wilmert C.S. De Bosscher
Nomenclature 427
11.1 Large-Area Magnetron Sputtering Basics 427
11.2 Magnetron and Process Concepts for Sputter Deposition of Metals 431
11.3 Tweaking Deposition Rate for Reactive Sputtering of SiO 2 434
11.4 Uniform Deposition of a Transparent Conductive Oxide (TCO) of Indium Tin Oxide (ITO) 436
11.5 Improved Process Stability and Performance for Metal Oxide Layers 439
11.6 Controlling Stoichiometry of Electrochromic Wo X Layers 442
11.7 High-Pressure Sputtering Increasing Mechanical Stability of NiO Layer 445
11.8 Conclusions 448
Acknowledgments 448
References 449
12 Vacuum Web Coaters and Their Large-Area Coatings Used in Chromogenic Products: Technology and Applications of Transparent Electronic Conductors 453
Paul Lippens
12.1 Vacuum Web or Roll Coaters 453
12.1.1 Definition, Basic Configuration 453
12.1.2 Industrial Systems Available on the Market 455
12.2 Coating Systems Produced on Web Coaters 458
12.2.1 Overview of a Few Important Coating Systems 458
12.2.2 An Important Building Module: Transparent Conducting Electrodes 459
12.2.2.1 Semiconducting ITO 459
12.2.2.2 Nodule Formation 460
12.2.2.3 Typical ITO Compositions for Web Coating 461
12.2.2.4 Other Transparent Electronic Conductors 463
12.3 Outlook 464
12.3.1 Web Coating on Thin Rollable Glass 464
12.3.2 Machine-Related Developments 465
12.3.2.1 Combination of Several Deposition Technologies on the Same Web Coater 465
12.3.2.2 Air-to-Air Coaters 465
References 466
13 Pyrolytic Fluorine-Doped Tin Oxide on Glass for Chromogenic Products 469
George Neuman
13.1 Introduction 469
13.2 The Development of Online Pyrolytic Deposition of Conductive Tin Oxide 469
13.3 Manufacturers 484
13.4 Chemical Vapor Deposition (CVD) 484
13.5 Properties 488
13.6 Color Suppression Technology (CSI) 493
13.7 Physical and Chemical Properties 494
13.8 Commercial Products 497
13.9 Conclusion 497
Acknowledgments 498
References 499
Index 503
About the Author :
After working on University- Industry projects at UC Berkeley -LBNL Carl M. Lampert, PhD, became a full-time consultant working for industry on chromogenics for architectural building glazing, automotive windows and sunroofs mirrors, train windows, and satellite surfaces for emissivity control in 2000. He has written many scholarly articles and has given lectures at companies such as Toyota Motors, Nissan Motors, Asahi Glass, DuPont, Applied Materials, JX Nippon Oil, Teijin, Toray Industries, and Dai Nippon Printing.
