OLED Science and Technology, 4 Volume Set

Hong Meng, PhD, is a Professor at the School of Advanced Materials, Peking University Shenzhen Graduate School, with over 30 years of experience in organic electronics. Previously at Bell Labs and DuPont Experimental Station, he has contributed over 230 peer-reviewed papers, filed over 46 US patents and 140 Chinese patents, and is recognized as a key inventor of deuterated blue host materials that addressed the persistent challenge of blue OLED operational lifetime.

• Volume IChapter 1. Introduction to Organic Light-Emitting Diodes. 11.1. Introduction. 11.1.1. Evolution and Milestones of OLED Technology. 21.1.2. OLED Technology Roadmap. 41.2. OLED Device Structure and Light Emission Mechanism.. 71.2.1. Classification of OLED Organic Layers. 71.2.2. OLED Light Emission Mechanism and Material Selection Principles. 71.2.3. Types of OLED Device Structure. 121.2.4. Tandem OLED Device Structure and Light Emission Mechanism.. 131.2.5. Flexible OLED Device Structure. 151.2.6. Transparent OLED Device Structure. 171.3. OLED Materials. 181.3.1. OLED Key Materials. 181.3.2. Organic Light-Emitting Materials. 191.3.3. Functional Organic Materials in OLEDs. 201.3.4. Printable OLED Materials. 221.3.5. Evolutionary and Technological Innovations in OLED Materials. 231.3.6. Technical Challenges in OLED Materials. 281.4. OLED Technology and Marketization. 311.4.1. OLED Technology and Market Development 311.4.2. OLED Industry Chain Analysis. 331.4.3. Market Prospects for OLED.. 341.4.4. Global Status and Challenges in OLED Technology Development 361.5. Future Outlook of OLED Technology. 401.5.1. Next-Generation OLED Materials: Challenges, Solutions, and Opportunities  401.5.2. Advancements and Future Prospects in OLED Device Development 451.6. Conclusions. 46References. 47  Chapter 2. Fundamental Concepts of Organic Light-Emitting Diodes 22.1. Key OLED Device Parameters 32.1.1. Luminescence Efficiency and Measurement 32.1.2. Luminance and Testing. 52.1.3. V-I Characteristics of OLED Devices 72.1.4. Density-Current-Voltage (J-V-L) Curve and Its Testing. 82.1.5. Electronic Energy Level Estimation and Its Testing. 92.1.6. Work Function. 132.1.7. Bond Dissociation Energy (BDE) 142.1.8. EL Emission Spectrum.. 142.1.9. CIE Coordinates 152.1.10. Correlated Color Temperature (CCT) 192.1.11. OLED Lifespan and Its Testing. 202.1.12. OLED Mobility and Measurement 242.2. Factors Affecting OLED Device Aging. 282.2.1. Factors Influencing OLED Luminescence Efficiency. 282.2.2. Factors Affecting OLED Lifetime. 332.3. Strategies for Improving OLED Device Performance. 342.3.1. Strategies for Enhancing OLED Device Luminescence Efficiency. 342.3.2. Strategies to Improve OLED Lifetime. 472.3. Conclusion. 55Reference：... 56  Chapter 3. Anode Materials for Organic Light-Emitting Diodes. 23.1. Introduction. 23.2. Anode Materials. 43.2.1. Metal Oxides. 43.2.2. Silver Nanowire or Nanomesh. 93.2.3. Graphene and Carbon Nanotube Films. 113.2.4. Semiconductor-Metal-Semiconductor Structure. 133.2.5. Top Emitting Anode. 153.3. Energy Level Alignment Theory. 163.3.1. Work Function and Fermi Level 163.3.2. Physical Significance of "Energy Level Alignment". 193.3.3. Weakly Interacting Interfaces, Fermi Level Pinning, and the ICT Model 203.3.4. Moderately Interacting Interfaces and the IDIS Model 223.3.5. Strongly Interacting Interfaces and Chemical Reactivity. 233.4. Energy Level Alignment Measurements. 243.4.1. Photoelectric Emission Spectrum.. 243.4.2. Layer by Layer UPS Measurement Method. 263.5. Summary. 26References 27  Chapter 4. Hole Injection Materials for Organic Light-Emitting Diodes. 14.1. Introduction. 14.2. Basic Requirements and Energy Level Considerations for Hole Injection Materials  34.2.1. Fundamental Requirements. 34.2.2. Energy Level Considerations. 34.3. Common Hole Injection Materials. 74.3.1. PEDOT:PSS. 74.3.2. Conjugated Polyelectrolyte Materials. 114.3.3. m-MTDATA Type. 124.3.4. CuPc Type. 134.3.5. Phenothiazine and Phenoxazine Derivatives. 164.3.6. Transition Metal Oxides (TMO) 174.3.7. Oxygen Plasma Treatment 244.3.8. Graphene Oxide Layer 244.3.9. Self-Assembled Materials. 254.3.10. HAT-CN.. 254.3.11. Other NTCDA Derivatives. 284.3.12. Phosphomolybdic Acid. 294.3.13. Carbon Nanotubes (CNTs) 314.4. Commercialized HIMs. 314.5. Conclusion and Outlook. 32References. 34Chapter 5. Hole Transport Materials for OLEDs. 25.1. Introduction. 25.2. Working principle of HTMs. 45.2.1 Polarization Submodel 55.2.2. Out-of-Order Models. 75.3. Performance Requirements for HTMs. 75.3.1. Hole Mobility and Its Test Methods. 85.3.2. HTM Energy Levels and Measurement Methods. 135.3.3. HTM Stability. 165.4. Progress in HTMs. 175.4.1. Advances in HTMs for Small Organic Molecules. 185.4.2. Crosslinkable/Polymer-HTMs. 635.4.3. Inorganic HTMs. 695.4.4. Organic-Inorganic Hybrid HTMs. 725.5. HTMs in Patents. 755.5.1. Asymmetric HTMs in Patents. 755.5.2. Doping Systems in Patents. 785.6. Technology Roadmap for HTMs. 825.7. Summary and Prospects. 845.8. References. 84Chapter 6. Carrier blocking layer materials for OLEDs. 26.1. Introduction. 26.2. The Role of Carrier Blocking Material 46.3. Hole Blocking Material 86.3.1. Requirements for Hole Blocking Materials. 86.3.2. Important Hole Blocking Material 86.4 Electron blocking material 346.4.1. Basic Requirements for Electron Blocking Materials. 346.4.2. Important Electronic Blocking Materials. 356.5 Conclusions and Outlook. 52Reference  54  Chapter 7. Fluorescent OLED material 27.1. Introduction. 37.2. Blue Fluorescent OLED Materials. 67.2.1. Classification of Blue OLED Material Systems​ 77.2.2. Performance Enhancement Strategies for Blue OLED Devices. 187.2.3. Development of Blue Fluorescent OLED Materials. 227.2.4. Challenges and Future Development Directions of Blue OLED Materials  397.2.5. Summary. 427.3. Red Fluorescent OLED Materials. 427.3.1. Classification of Red OLED Materials. 447.3.2 The Development of Red Fluorescent OLED Materials. 637.3.3 Summary. 707.4. Green Fluorescent OLED Materials. 707.4.1 Classification of Green Light OLED Materials. 707.4.2. Development of Green Fluorescent OLED Materials. 787.4.3. Summary. 847.5 Summary. 84Reference  86  Chapter 8. Phosphorescent OLED materials. 38.1. Introduction of Phosphorescent Materials. 38.1.1. Phosphorescent Principle. 48.1.2. Classification of Phosphorescent Materials. 58.1.3. Cyclometalated Iridium(III) Complexes 78.1.4. Relationship between Luminescent Properties and Ligands. 128.2. Green Phosphorescent Materials 178.2.1. Green phosphorescent guest materials. 178.2.2. Green Phosphorescent Host Materials. 228.2.3. Summary and Outlook. 368.3. Red Phosphorescent Materials. 378.3.1 Basic Requirements. 378.3.2. Problems Existing in Red Phosphorescent Guest Materials. 378.3.3. Effects of Ligands on the Performance, Photochemistry, and Energy Level of Red Phosphorescent Materials. 388.3.4. Red Phosphorescent Guest Materials. 408.3.5. Host Materials for Red Phosphorescence. 488.3.6. Summary and Outlook. 578.4. Blue Phosphorescent Materials 588.4.1. Basic Requirements for Blue Phosphorescent Materials. 588.4.2. Introduction of Major Blue Phosphorescent Iridium Complexes. 598.4.3. Example of Blue Phosphorescent Material Synthesis. 688.4.4. Introduction of Blue Phosphorescent Host Material 718.4.5. Blue Phosphorescent OLED Device Structure. 768.4.6. Summary and Outlook. 828.5. Near-Infrared Phosphorescent Materials. 838.5.1. Emission Spectra of Near-Infrared Colour Phosphorescent Guest Materials 848.5.2. Influence of Molecular Ligand π-Conjugation Length on NIR Materials. 878.5.3. Ligand Substituent Effects on Phosphorescent Material Properties, Photochemistry and Energy Levels  898.5.4. Effects of Heteroatoms in Ligands on Near-Infrared Materials 908.5.5. Donor-Acceptor Structure in Ligands on Near-Infrared Materials. 918.5.6. Intramolecular Metal-Metal Interactions on Near-Infrared Materials. 928.5.7. Other Factors Affecting NIR Materials. 938.5.8. Luminescence Efficiency and Thermal Stability of NIR Phosphorescent Guest 94Materials. 948.5.9. Introduction to Organic NIR Phosphorescent Host Materials 958.5.10. Near-Infrared Phosphorescent Host Material 1108.5.11. Near-Infrared OLED Device Structure and Device Optimisation. 1128.5.12. Summary and Outlook. 1148.6. Summary. 116Reference. 118  Chapter 9. Pt-Pd Phosphorescent Materials. 29.1 Introduction to Pt-Pd Phosphorescent Materials. 29.1.1 Background of Pt Phosphorescent Materials. 29.1.2 Background of Pd Phosphorescent Materials. 39.1.3 Phosphorescence Mechanism of Pt-Pd Cyclometalated Complexes. 59.1.4 Comparison Between Pt-Pd and Iridium-Based Phosphorescent Emission. 69.2 Development and Classification of Pt-Pd Phosphorescent Materials. 79.2.1 Development of Pt- and Pd-based phosphorescent complexes. 79.2.2 Porphyrin-Based Tetradentate Pt-Pd Complex Systems. 89.2.3 N₂O₂ Ligand-Based Tetradentate Pt-Pd Complex Systems. 109.2.4 Pyrazole-Based Tetradentate Pt-Pd Complex Systems. 139.2.5 N-Heterocyclic Carbene-Based Tetradentate Pt-Pd Complex Systems. 189.2.6 Imidazole-Based Tetradentate Pt-Pd Complex Systems. 219.2.7 Pyridine-Based Tetradentate Pt-Pd Complex Systems. 239.2.8 [N^C^C^N] Pt-Pd Complex Systems. 289.2.9 [O^N^C^N] Pt-Pd Complex Systems. 319.2.10 Other Tetradentate Pt-Pd Complex Systems. 379.3 Synthetic Examples of Phosphorescent Pt-Pd Complexes. 399.4 Summary and Outlook. 41Reference. 43  Volume IIChapter 1: Fundamentals of TADF.. 41.1. Introduction to TADF Materials. 41.1.1. History of TADF Materials and OLED Development 5​​1.1.2. TADF---The Rising Star of OLED Materials in Academia and Industry. 61.1.3. Definition and Fundamental Principles. 81.1.3.1. Definition of TADF​ 8​1.1.3.2. Key Principles Governing TADF​ 8​1.1.3.3. Kinetic Model of TADF​ 9​1.1.3.4. Spin Statistics, Exciton Dynamics (singlet-triplet ratio), and 100% IQE Potential 91.1.3.5. TADF: 100% IQE Realization. 111.1.3.6. TADF Comparison with Other Luminescent Mechanisms​ 12​1.2. Photophysics and Mechanisms of TADF​ 13​1.2.1. TADF Mechanisms ​ 13​​1.2.1.1. RISC Process​ 17​​1.2.1.2. TADF Key Photophysical Properties​ 18​1.2.2. Advanced Phenomena​---TADF Material design. 18​​1.2.2.1. Hybridized Local and Charge-Transfer (HLCT)​​ 181.2.2.2. Triplet-Triplet Annihilation (TTA)​​ 201.2.2.3. Exciton Splitting (Singlet Exciton Fission) 22​​1.2.2.4. Multi-Resonance TADF (MR-TADF)​​ 24​​1.2.2.5. Heavy-Atom Effects​ 26​1.2.3. Emerging Directions​ of TADF.. 271.2.3.1. Triplet Harvesting Beyond RISC---Hot Excitons. 27​1.2.3.2. Multi-Resonance Expansion---Heteroatom Variations. 291.2.3.3. Machine Learning-Guided Design TADF Molecules. 30Chapter 2: Molecular Design I: Donor–Acceptor Architectures. 382.1. Twisted Donor-Acceptor (TDA) Molecular Geometries. 392.2. TADF through-bond Charge Transfer (TBCT) 632.3. TADF Molecules Through Space Charge Transfer (TSCT) 64Chapter 3: Molecular Design II: Multi-Resonance (MR-TADF) 693.1. Classification of MR-TADF Emitters. 723.2. Synthesis of MR-TADF Emitters. 743.3. Modulation and Construction of MR-TADF Emitters. 793.4. MR-TADF with Circularly Polyarized Emission.. 863.5. Future Directions​ of MR-TADF. 100Chapter 4: Molecular Design III: Metal-Complex TADF.. 1024.1. Cu(I) Complexes TADF. 1034.2. Au(III) TADF Emitters. 1264.3. Ag(I) TADF Emitters. 1374.4. Pt(II) Complex TADF Materials. 1384.5. Pd(II) Complex TADF Materials. 1414.6. Zn(II) Complex TADF Materials. 1424.7. Sn(II) Complex TADF Materials. 1444.8. Al(III) Complex TADF Materials. 1454.9. Comparation of Different Type of TADF Materials. 1474.10. Determining Emission Nature of the Metal Complex.. 1474.11. Conclusion and Perspective of TADF Metal Complex.. 148Chapter 5: Macromolecular TADF: Dendrimers & Polymers. 1515.1. TADF Dendritic Macromolecule. 1515.1.1 TADF dendritic macromolecule with conjugated bonds. 1525.1.2. TADF dendritic macromolecule with non-conjugated bonds. 1605.2. Polymer TADF Materials​ 1645.2.1. Conjugated Main-Chain TADF Polymers. 1655.2.2. Non Conjugated TADF Polymers. 1725.2.3. Advantages of Polymer TADF. 182​5.2.4. Challenges of Polymer TADF OLED Materials and Future Perspective. 183Chapter 6: TADF as Host Materials: Design & Applications. 1846.1. Introduction to TADF Hosts​ 1846.2. TADF High Triplet Energy Hosts for Exciton Confinement. 1846.3. TADF Hosts with Phosphorescent Emitters ​ 1866.4. TADF Hosts with Fluorescent Emitters ​ 1886.5. TADF Hosts with TADF Emitters ​ 1906.6. TADF Exciplex Hosts ​ 1926.7. MR-TADF Hosts​ 1936.8. Bifunctional Hosts with TADF Properties​ 1966.9. Pure Hydrocarbon Hosts for MR-TADF. 1986.10. Deuterium TADF Hosts. 2016.11. Summary of TADF Hosts. 203Chapter 7: Organic TADF Emitters by Color.. 2047.1. Blue TADF emitters. 2047.2. Green TADF emitters. 2077.3. Red TADF emitters. 2117.4. Organic Near-infrared-TADF materials. 2157.5. TADF White light Emitters. 2187.5.1. Hybrid TADF WOLEDs. 2267.5.2. All Fluorescent TADF WOLEDs. 2297.5.3. Single Molecule TADF WOLEDs. 231Chapter 8: MR-TADF Emitters: Strategies & Breakthroughs. 2378.1. Blue MR-TADF Emitters. 2388.2. Green MR-TADF Emitters. 2418.3. Red and Infrared MR-TADF Emitters. 2448.4. Infrared MR-TADF Emitters. 2478.5. Heavy-Atom Enhanced MR-TADF. 249Chapter 9: Advanced Applications. 2559.1. TADF-sensitized Hyperfluorescence Systems ​ 255​9.1.1 Energy Transfer Mechanism: 257​9.1.2. TADF-sensitized Hyperfluorescence Design Strategies​ 2589.1.3. High Performance TADF-sensitized Hyperfluorescence OLEDs. 2619.1.4. Cu(I)-TADF-sensitized Hyperfluorescence (DSF) 271​9.1.5. Doublet-sensitized Hyperfluorescence (DSF) 2749.2. Phosphorescent-sensitized Hyperphosphorescent OLEDs ​ 2779.2.1. Introduction of Hyperphosphorescent (HP) OLEDs. 2799.2.2. Materials for Hyperphosphorescent OLEDs. 2809.3. Machine Learning and AI+OLED Materials Design ​ 2939.3.1. ΔEST and FWHM Prediction. 2969.3.2. Emission Wavelength (λPL) Optimization. 2989.3.3. Molecular Stability Screening---Tg/Td. 3009.3.4. Molecular Stability Screening---BDE (Bond Dissociation Energy) 3019.3.5. Machine Learning & High-Throughput Screening for MR-TADF Scaffolds. 3039.3.6. Machine Learning for OLED Materials: Challenges & Future Directions. 306  Volume IIChapter 1: Fundamentals of TADF.. 41.1. Introduction to TADF Materials. 41.1.1. History of TADF Materials and OLED Development 5​​1.1.2. TADF---The Rising Star of OLED Materials in Academia and Industry. 61.1.3. Definition and Fundamental Principles. 81.1.3.1. Definition of TADF​ 8​1.1.3.2. Key Principles Governing TADF​ 8​1.1.3.3. Kinetic Model of TADF​ 9​1.1.3.4. Spin Statistics, Exciton Dynamics (singlet-triplet ratio), and 100% IQE Potential 91.1.3.5. TADF: 100% IQE Realization. 111.1.3.6. TADF Comparison with Other Luminescent Mechanisms​ 12​1.2. Photophysics and Mechanisms of TADF​ 13​1.2.1. TADF Mechanisms ​ 13​​1.2.1.1. RISC Process​ 17​​1.2.1.2. TADF Key Photophysical Properties​ 18​1.2.2. Advanced Phenomena​---TADF Material design. 18​​1.2.2.1. Hybridized Local and Charge-Transfer (HLCT)​​ 181.2.2.2. Triplet-Triplet Annihilation (TTA)​​ 201.2.2.3. Exciton Splitting (Singlet Exciton Fission) 22​​1.2.2.4. Multi-Resonance TADF (MR-TADF)​​ 24​​1.2.2.5. Heavy-Atom Effects​ 26​1.2.3. Emerging Directions​ of TADF.. 271.2.3.1. Triplet Harvesting Beyond RISC---Hot Excitons. 27​1.2.3.2. Multi-Resonance Expansion---Heteroatom Variations. 291.2.3.3. Machine Learning-Guided Design TADF Molecules. 30Chapter 2: Molecular Design I: Donor–Acceptor Architectures. 382.1. Twisted Donor-Acceptor (TDA) Molecular Geometries. 392.2. TADF through-bond Charge Transfer (TBCT) 632.3. TADF Molecules Through Space Charge Transfer (TSCT) 64Chapter 3: Molecular Design II: Multi-Resonance (MR-TADF) 693.1. Classification of MR-TADF Emitters. 723.2. Synthesis of MR-TADF Emitters. 743.3. Modulation and Construction of MR-TADF Emitters. 793.4. MR-TADF with Circularly Polyarized Emission.. 863.5. Future Directions​ of MR-TADF. 100Chapter 4: Molecular Design III: Metal-Complex TADF.. 1024.1. Cu(I) Complexes TADF. 1034.2. Au(III) TADF Emitters. 1264.3. Ag(I) TADF Emitters. 1374.4. Pt(II) Complex TADF Materials. 1384.5. Pd(II) Complex TADF Materials. 1414.6. Zn(II) Complex TADF Materials. 1424.7. Sn(II) Complex TADF Materials. 1444.8. Al(III) Complex TADF Materials. 1454.9. Comparation of Different Type of TADF Materials. 1474.10. Determining Emission Nature of the Metal Complex.. 1474.11. Conclusion and Perspective of TADF Metal Complex.. 148Chapter 5: Macromolecular TADF: Dendrimers & Polymers. 1515.1. TADF Dendritic Macromolecule. 1515.1.1 TADF dendritic macromolecule with conjugated bonds. 1525.1.2. TADF dendritic macromolecule with non-conjugated bonds. 1605.2. Polymer TADF Materials​ 1645.2.1. Conjugated Main-Chain TADF Polymers. 1655.2.2. Non Conjugated TADF Polymers. 1725.2.3. Advantages of Polymer TADF. 182​5.2.4. Challenges of Polymer TADF OLED Materials and Future Perspective. 183Chapter 6: TADF as Host Materials: Design & Applications. 1846.1. Introduction to TADF Hosts​ 1846.2. TADF High Triplet Energy Hosts for Exciton Confinement. 1846.3. TADF Hosts with Phosphorescent Emitters ​ 1866.4. TADF Hosts with Fluorescent Emitters ​ 1886.5. TADF Hosts with TADF Emitters ​ 1906.6. TADF Exciplex Hosts ​ 1926.7. MR-TADF Hosts​ 1936.8. Bifunctional Hosts with TADF Properties​ 1966.9. Pure Hydrocarbon Hosts for MR-TADF. 1986.10. Deuterium TADF Hosts. 2016.11. Summary of TADF Hosts. 203Chapter 7: Organic TADF Emitters by Color.. 2047.1. Blue TADF emitters. 2047.2. Green TADF emitters. 2077.3. Red TADF emitters. 2117.4. Organic Near-infrared-TADF materials. 2157.5. TADF White light Emitters. 2187.5.1. Hybrid TADF WOLEDs. 2267.5.2. All Fluorescent TADF WOLEDs. 2297.5.3. Single Molecule TADF WOLEDs. 231Chapter 8: MR-TADF Emitters: Strategies & Breakthroughs. 2378.1. Blue MR-TADF Emitters. 2388.2. Green MR-TADF Emitters. 2418.3. Red and Infrared MR-TADF Emitters. 2448.4. Infrared MR-TADF Emitters. 2478.5. Heavy-Atom Enhanced MR-TADF. 249Chapter 9: Advanced Applications. 2559.1. TADF-sensitized Hyperfluorescence Systems ​ 255​9.1.1 Energy Transfer Mechanism: 257​9.1.2. TADF-sensitized Hyperfluorescence Design Strategies​ 2589.1.3. High Performance TADF-sensitized Hyperfluorescence OLEDs. 2619.1.4. Cu(I)-TADF-sensitized Hyperfluorescence (DSF) 271​9.1.5. Doublet-sensitized Hyperfluorescence (DSF) 2749.2. Phosphorescent-sensitized Hyperphosphorescent OLEDs ​ 2779.2.1. Introduction of Hyperphosphorescent (HP) OLEDs. 2799.2.2. Materials for Hyperphosphorescent OLEDs. 2809.3. Machine Learning and AI+OLED Materials Design ​ 2939.3.1. ΔEST and FWHM Prediction. 2969.3.2. Emission Wavelength (λPL) Optimization. 2989.3.3. Molecular Stability Screening---Tg/Td. 3009.3.4. Molecular Stability Screening---BDE (Bond Dissociation Energy) 3019.3.5. Machine Learning & High-Throughput Screening for MR-TADF Scaffolds. 3039.3.6. Machine Learning for OLED Materials: Challenges & Future Directions. 306Chapter 10: Challenges, Commercialization & Outlook.. 30810.1. Stability: The Degradation Mechanism of MR-TADF Blue Materials​ 30810.2. Tackling Efficiency Roll-off in Blue TADF OLEDs​ 31010.3. Commercialization Pathways​​ 31210.4. Outlook of TADF OLED Materials​​ 312REFERENCE.. 329  Volume III  Chapter 11. Host Materials 211.1. Introduction to Host Materials 211.1.1. Energy Level Analysis of The Host Material in OLED Devices 311.1.2. The requirements and design of host Materials 611.1.3. Calculation and simulation of host materials 711.1.4. Main Performance Indicators of the Host Material 1011.2. Classification of Host Materials 1611.2.1. Pure CH Aromatic Ring Based Host Material 1611.2.2. Hole Transporting Host Material 2511.2.3. Electron Transporting Host Material 3711.2.4. Bipolar Host Material 4011.2.5. Hybrid host material 6611.3. Commercial Host Materials 7511.3 .1. Blue Host Materials 7511.3 .2. Red Host Material 8111.3.3. Green Host Material 8611.4. Conclusion and Outlook. 90Reference: 91Chapter 12. OLED Materials and Devices Based on AIE Characteristics. 212.1. AIE Concept 212.2. Fundamental Principles of AIE.. 312.2.1. Restriction of Intramolecular Motion. 312.2.2. Restriction of Intramolecular Rotation. 412.2.3. Restriction of Intramolecular Vibration. 612.3. Development History. 812.3.1. Emergence of the AIE Concept 812.3.2. Establishment of AIE Application Fields and Conceptual Solidification  912.3.3. Expansion of AIE Research Applications. 912.4. Classification of AIE Fluorescent Materials. 1112.4.1. Pure AIE Fluorescent Materials. 1112.4.2. AIE-Activated Delayed Fluorescence Materials. 1212.4.3. AIE Phosphorescent Materials. 1312.4.4. AIE Polymeric Materials. 1312.5. AIE-Based OLED Materials and Devices. 1512.5.1. Blue AIE OLED Materials and Devices. 1512.5.2. Green AIE OLED Materials and Devices. 1712.5.3. Red AIE OLED Materials and Devices. 2012.5.4. AIE Near-Infrared OLED Materials and Devices. 2312.5.5. AIE White OLED Materials and Devices. 2612.6. Conclusions and Future Perspectives. 28Reference  29  Chapter 13. Electron Transport Materials. 213.1. Introduction. 213.2. Performance Requirements for ETMs. 213.2.1. Physical Properties. 313.2.2. Chemical Properties. 613.2.3. Thermal Properties. 813.2.4. Compatibility with Other Materials. 1013.3. Categories of Organic Electron Transport Materials. 1213.3.1. Aromatic Ring Compounds. 1213.3.2. Nitrogen-Containing Heterocycles. 2313.3.3. Electron-Deficient Element Category. 3513.3.4. Silicon-Based Broadband Semiconductor Materials. 3613.3.5.Phosphorus Oxide Compounds. 3813.3.6. Multilayer Hybrid Electron Transport Materials. 4013.3.7. Carbon Quantum Dots as Electron Transport Materials. 4113.3.8. Metal Chelates. 4213.4. Modification Strategies for Electron Transport Materials. 4413.4.1. Introduction of Cyano Groups. 4413.4.2. Influence of Nitrogen Atom Position in Pyridine Rings. 4513.4.3. Planarity of Molecular Structure. 4613.4.4. Enhancing Electron Conductivity through N-Doping. 4613.4.5. Influence of Dipole Moments. 4813.4.6. Combination of Metal Complexes. 4813.5. Summary and Outlook. 50Reference. 52  Chapter 14 Electron Injection Materials 114.1 Introduction. 214.2 Energy Level Structure. 314.3 Common Electron Injection Materials 414.3.1 LiF. 414.3.2 Liq. 614.3.3 Cs₂CO₃ 714.3.4 Triazine Derivatives 814.3.5 ZnO/PEI 1014.3.6 PEIE. 1314.3.7 PEI-Conjugated Polymer 1614.3.8 Solution-Processed EIM.. 1814.3.9 Super Base. 2114.3.10 DNA and Nucleic Acids as EIM.. 2314.3.11 Doping-Conjugated Molecules 2514.4 Summary and Outlook. 25Reference. 28Chapter 15 Cathode Materials 215.1 Introduction. 215.2 Elemental Metals 315.3 Alloy Materials 415.4 Multi-layer Metal Structure. 615.5 Metal Compounds 715.5.1 Inorganic Metal Compounds 815.5.2 Organometallic Complexes 915.6 Composite Materials and Interface Engineering. 1115.7 Top Emitting Device Cathode. 1315.8 Summary. 16References 17Chapter 16 OLED coupling Layer（CPL）... 216.1 Introduction. 216.2 External Light Extraction Techniques (ELE) 416.2.1 Surface Roughening. 516.2.2 Microlens Array (MLA) 716.2.3 Patterned Surface Films 916.2.4 Scattering Media Layers 1016.3 Internal Light Extraction Techniques (ILE) 1216.3.1 Insertion of Low-Refractive-Index or Scattering Layers 1216.3.2 Patterned Transparent Electrodes 1416.3.3 Photonic Crystals 1716.3.4 Surface Plasmon Polariton (SPP) Coupling. 1916.4 Light Extraction Layer Materials 2216.4.1 Inorganic Light Extraction Materials 2416.4.2 Organic Light Extraction Materials 2616.5 Summary. 4016.6 Reference. 41Chapter 17 White Organic Electroluminescent Devices............................................... 317.1 Introduction..................................................................................................... 317.2 WOLED Device Classification....................................................................... 617.3 Overview of WOLED Efficiency Developments........................................... 717.4 Pure Phosphorescent, Sensitized Phosphorescent, and Doped WOLEDs...... 917.4.1Sensitized TADF-phosphorescent WOLEDs...................................... 1617.4.2Radical complexes WOLEDs............................................................. 1617.5 Specialty White Light Devices WOLEDs.................................................... 1717.5.1 Single material WOLEDs.................................................................. 1717.5.2 Ultra-thin WOLEDs........................................................................... 1817.5.3 Circularly polarized WOLEDs........................................................... 1917.6 Strategies to Enhance the Operating Performance of WOLEDs.................. 2017.6.1 Increasing charge injection to reduce operating voltage.................... 2017.6.2 Electrical doping to reduce operating voltage.................................... 2417.6.3 Outcoupled Capture to Improve Light Extraction Efficiency............ 2717.7 Color Purity of WOLEDs (Color of WOLEDs)........................................... 3217.7.1 Color coordinates............................................................................... 3417.7.2 Color stability..................................................................................... 3617.7.3 High CRI WOLEDs........................................................................... 4117.8 WOLEDs with different device structures................................................... 4917.8.1 Laminated WOLEDs.......................................................................... 4917.8.2 Top-Emitting and Transparent WOLEDs.......................................... 5517.8.3 WOLEDs with Simplified Device Architecture................................ 6817.9 WOLEDs in Lighting and Displays.............................................................. 7117.9.1 Applications in lighting...................................................................... 7117.9.2 Applications in displays..................................................................... 8017.9.3 AMOLED vs. TFT-LCD.................................................................... 8617.9.4 WOLED Development and Challenges............................................. 88bibliography................................................................................................................. 91Chapter 18 High-Efficiency Solution-Processed OLED Materials and Devices. 3Preface. 318.1 Classification of Solution-Processed OLED Materials and Devices. 418.2  OLED Device Fabrication Processes by Solution Methods. 618.2.1 Spin Coating Process. 618.2.2 Printing Process. 718.2.3 Roll-to-Roll (R2R) Process. 1218.3 Solution-Processed Hole Injection and Transport Materials HIM/HTM... 1818.3.1 Inorganic Doped Hole Injection Materials. 1818.3.2 Polymer Hole Injection Materials. 2118.3.3 Cross-Linkable Hole Transport Materials. 2218.4 Solution-Processed EIM and ETM Materials. 2918.5 Solution-Processed Host and Emitting Materials. 3318.5.1 Solution-Processed Host Materials. 3318.5.2 Solution-Processed Emitting Materials. 3518.6 Solution-Processed Charge-generation Layer CGL and Tandem OLED Devices. 4118.7 Development of Solution-Processed OLED in Industry. 4418.8 Conclusion and Outlook. 4718.9  References  49Chapter 19 Purification of OLED materials. 119.1 Introduction. 119.2 The influence of purity on device performance. 219.3 Material purification method. 319.3.1 Sublimation purification. 419.3.2 Zone melting. 919.3.3 Recrystallization. 1119.3.4 Chromatographic column purification. 1219.3.5 Ionic liquid purification. 1419.3.6 Continuous gasification purification. 1519.4 Conclusion and Prospect 19Reference. 19Volume IV  Chapter 20 Preparation of Deuterated OLED Materials. 220.1 Introduction. 220.2 Lifetime enhancement of deuterated OLED materials. 320.2.1 Deuterium effect 420.2.2 The Effect of Deuteration on OLED Materials. 820.2.3 Deuteration theory analysis and calculation. 1420.3 Synthesis and Process of Deuterated Compounds. 1720.3.1 Deuterated benzene and its synthesis method. 1720.3.2 Synthesis of Deuterated Aromatic Compounds. 2020.3.3 Synthesis of deuterated alkyl chains and side chains. 2620.4 Synthesis of Deuterated OLED Materials. 2920.4.1 Using D/H exchange to directly deuterated materials. 2920.4.2 Fragment synthesis method using deuterated raw materials. 2920.5 Summary and Prospect of Deuterated OLED Materials. 32Reference. 33Chapter 21: Enhancing OLED Device Performance through Molecular Orientation. 221.1 Introduction. 221.1.1 Fundamental Concepts of Molecular Orientation. 321.1.2 Impact of Molecular Orientation on Device Performance. 321.1.3 Instruments and Methods for Measuring Molecular Orientation. 521.2 Impact of Molecularly Oriented HTMs on Device Performance. 1121.2.1 Relationship Between Molecular Structure and Orientation. 1221.2.2 Designing Horizontally Oriented HTMs. 1321.3 Impact of Molecularly Oriented ETMs on Device Performance. 1621.4 Impact of Molecularly Oriented Emissive Materials on Device Performance. 1821.5 Impact of Host Material Orientation on Device Performance. 2021.5.1 Bulky and Rigid Host Materials. 2521.5.2 Rod-Like Host Materials. 2621.6 Strategies for Fabricating Horizontally Oriented Molecular Thin Films. 2621.7 Conclusions and Outlook. 27Reference  28Chapter 22: OLED Lifetime and Aging. 222.1 OLED Lifetime and Related Concepts. 222.1.1 Defects. 222.1.2 Dark Spots. 322.1.3 Lifetime Testing. 322.2 Factors Influencing OLED Aging. 522.2.1 Extrinsic Aging. 522.2.2 Intrinsic Aging. 522.3 Strategies to Enhance OLED Lifetime. 622.3.1 Novel Material Development 622.3.2 Long-Lifetime Device Architectures. 822.3.3     Material and Process Optimization. 1122.4 Summary and Outlook. 1322.5 Reference. 15Chapter 22: OLED Lifetime and Aging. 222.1 OLED Lifetime and Related Concepts. 222.1.1 Defects. 222.1.2 Dark Spots. 322.1.3 Lifetime Testing. 322.2 Factors Influencing OLED Aging. 522.2.1 Extrinsic Aging. 522.2.2 Intrinsic Aging. 522.3 Strategies to Enhance OLED Lifetime. 622.3.1 Novel Material Development 622.3.2 Long-Lifetime Device Architectures. 822.3.3     Material and Process Optimization. 1122.4 Summary and Outlook. 1322.5 Reference. 15Chapter 24 OLED Material Calculations. 224.1 Overview of OLED Material Simulation and Background. 224.1.1 OLED material development process and its important property parameters  324.1.2 Introduction to the OLED Material Computational Simulation Program.. 524.2 Material calculations and analysis at the molecular level 924.2.1 Theoretical Analysis of Material Structure and Properties of Luminous Layers  1024.2.2 Theoretical analysis of the material structure and properties of charge injection and transport layers. 1524.3 Computational Simulation at the Forefront of OLED Material Design. 1924.3.1 Examples of applications of computational simulation in the field of OLED material design  1924.3.2 Examples of Subject Groups and Research Results in the Field of OLED Material Simulation and Computing. 2524.4 Summary and Outlook. 33References: 35  25.1 Introduction2 25.2 Standard Paradigms for OLED Device Simulation2 25.2.1 Quantum mechanical calculations2 25.2.2 Molecular force field methods3 25.2.3 Kinetic Monte Carlo simulation4 25.3 Introduction to OLED Device Efficiency Roll Off4 25.4 Analytic Modeling of Efficiency and Efficiency Roll-offs8 25.5 Introduction to Progress in OLED Device Simulation Work8 25.5.1 Phosphorescent OLED device roll-off simulation8 25.5.2 Thermally activated delayed fluorescence (TADF) roll-off simulation10 25.5.3 KMC Simulation of Multilayer White OLED Devices10 25.5.4 High Fluorescence OLED Device Simulation12 25.6 Introduction to Machine Learning Simulation of OLED Devices13 25.6.1 Simulation of glass transition temperature of OLED materials16 25.6.2 Simulation of structure-efficiency correlation of blue phosphorescent device layers17 25.6.3 Active Learning Simulation Screening of OLED Materials18 25.6.4 Multiscale Simulation of OLED Device Mobility20 25.6.5 Application of Machine Learning in TADF Devices21 25.7 Summary22 Bibliography24    TOC \o "1-3" \h \z \u 25.1 Introduction. PAGEREF _Toc208347444 \h 2 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300038003300340037003400340034000000 25.2 Standard Paradigms for OLED Device Simulation. PAGEREF _Toc208347445 \h 2 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300038003300340037003400340035000000 25.2.1 Quantum mechanical calculations. PAGEREF _Toc208347446 \h 2 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300038003300340037003400340036000000 25.2.2 Molecular force field methods. PAGEREF _Toc208347447 \h 3 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300038003300340037003400340037000000 25.2.3 Kinetic Monte Carlo simulation. PAGEREF _Toc208347448 \h 4 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300038003300340037003400340038000000 25.3 Introduction to OLED Device Efficiency Roll Off PAGEREF _Toc208347449 \h 4 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300038003300340037003400340039000000 25.4 Analytic Modeling of Efficiency and Efficiency Roll-offs. PAGEREF _Toc208347450 \h 8 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300038003300340037003400350030000000 25.5 Introduction to Progress in OLED Device Simulation Work. PAGEREF _Toc208347451 \h 8 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300038003300340037003400350031000000 25.5.1 Phosphorescent OLED device roll-off simulation. PAGEREF _Toc208347452 \h 8 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300038003300340037003400350032000000 25.5.2 Thermally activated delayed fluorescence (TADF) roll-off simulation. PAGEREF _Toc208347453 \h 10 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300038003300340037003400350033000000 25.5.3 KMC Simulation of Multilayer White OLED Devices. PAGEREF _Toc208347454 \h 10 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300038003300340037003400350034000000 25.5.4 High Fluorescence OLED Device Simulation. PAGEREF _Toc208347455 \h 12 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300038003300340037003400350035000000 25.6 Introduction to Machine Learning Simulation of OLED Devices. PAGEREF _Toc208347456 \h 13 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300038003300340037003400350036000000 25.6.1 Simulation of glass transition temperature of OLED materials. PAGEREF _Toc208347457 \h 16 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300038003300340037003400350037000000 25.6.2 Simulation of structure-efficiency correlation of blue phosphorescent device layers  PAGEREF _Toc208347458 \h 17 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300038003300340037003400350038000000 25.6.3 Active Learning Simulation Screening of OLED Materials. PAGEREF _Toc208347459 \h 18 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300038003300340037003400350039000000 25.6.4 Multiscale Simulation of OLED Device Mobility. PAGEREF _Toc208347460 \h 20 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300038003300340037003400360030000000 25.6.5 Application of Machine Learning in TADF Devices. PAGEREF _Toc208347461 \h 21 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300038003300340037003400360031000000 25.7 Summary. PAGEREF _Toc208347462 \h 22 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300038003300340037003400360032000000 Bibliography. PAGEREF _Toc208347463 \h 24 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300038003300340037003400360033000000 Chapter 26: Stretchable OLEDs – Technology, Applications, and Future Trends​26.1. Introduction to Stretchable OLEDs​ PAGEREF _Toc205248670 \h 2 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003200340038003600370030000000 26.1.1. Definition and Evolution from Flexible, Foldable to Stretchable Displays. PAGEREF _Toc205248671 \h 4 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003200340038003600370031000000 26.1.2. Importance in Next-Generation Electronics. PAGEREF _Toc205248672 \h 4 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003200340038003600370032000000 26.1.3. Key Parameters to Characterize the Stretchability of OLEDs. PAGEREF _Toc205248673 \h 7 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003200340038003600370033000000 26.2. Fundamental Technologies Enabling Stretchability. PAGEREF _Toc205248674 \h 9 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003200340038003600370034000000 26.2.1. Material Innovations. PAGEREF _Toc205248675 \h 10 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003200340038003600370035000000 26.2.2. Structural Designs for Stretchable OLEDs. PAGEREF _Toc205248676 \h 29 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003200340038003600370036000000 26.2.3. Emerging Hybrid Approaches​ PAGEREF _Toc205248677 \h 32 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003200340038003600370037000000 26.3. Manufacturing Processes for Stretchable OLEDs​ PAGEREF _Toc205248678 \h 34 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003200340038003600370038000000 26.3.1. Sequential Coating Techniques for Enhanced Elasticity. PAGEREF _Toc205248679 \h 35 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003200340038003600370039000000 26.3.2. Thin-Film Deposition and Encapsulation Methods​ PAGEREF _Toc205248680 \h 37 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003200340038003600380030000000 26.3.3. Challenges in Scalability and Defect Mitigation​ PAGEREF _Toc205248681 \h 40 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003200340038003600380031000000 26.4. Performance Metrics and Advancements in Stretchable OLEDs​ PAGEREF _Toc205248682 \h 43 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003200340038003600380032000000 26.4.1. Efficiency and Brightness: Current Achievements​ PAGEREF _Toc205248683 \h 44 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003200340038003600380033000000 26.4.2. Durability: Long-Term Mechanical Robustness​ PAGEREF _Toc205248684 \h 44 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003200340038003600380034000000 26.4.3. Color Purity and Viewing Angle Stability​ PAGEREF _Toc205248685 \h 45 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003200340038003600380035000000 26.5. Applications of Stretchable and Flexible OLEDs across Industries. PAGEREF _Toc205248686 \h 46 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003200340038003600380036000000 26.5.1. Wearable Electronics: Health Monitoring and Smart Clothing​ PAGEREF _Toc205248687 \h 47 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003200340038003600380037000000 26.5.2. Automotive Displays: Dynamic Dashboards and Swiveling Screens. PAGEREF _Toc205248688 \h 53 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003200340038003600380038000000 26.5.3. Consumer Electronics: Foldable Phones and Rollable TVs​ PAGEREF _Toc205248689 \h 55 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003200340038003600380039000000 26.5.4. Medical Devices: Conformable Patches and Surgical Tools​ PAGEREF _Toc205248690 \h 58 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003200340038003600390030000000 26.6. Challenges and Limitations in Flexible/Stretchable OLED Technology. PAGEREF _Toc205248691 \h 61 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003200340038003600390031000000 26.6.1. Efficiency Roll-Off at High Brightness​ PAGEREF _Toc205248692 \h 62 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003200340038003600390032000000 ​26.6.2. Degradation and Lifetime Issues​ PAGEREF _Toc205248693 \h 63 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003200340038003600390033000000 26.7. Future Trends and Innovations in Flexible OLED Technology​ PAGEREF _Toc205248694 \h 64 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003200340038003600390034000000 26.7.​1. Intrinsically Stretchable PHOLEDs for Higher Brightness​ PAGEREF _Toc205248695 \h 65 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003200340038003600390035000000 26.7.2. Multi-Functional Integration (Displays with Built-In Sensors/Speakers)​​ PAGEREF _Toc205248696 \h 65 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003200340038003600390036000000 ​26.7.3. Market Projections: $500M+ Automotive Display Market by 2028​ PAGEREF _Toc205248697 \h 66 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003200340038003600390037000000 26.8. Future Outlook of Stretchable OLED Technology. PAGEREF _Toc205248698 \h 67 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003200340038003600390038000000 26.9. Appendix and Final Outlook​ PAGEREF _Toc205248699 \h 68 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003200340038003600390039000000 ​ 26.9.1. Roadmap for commercialization​ PAGEREF _Toc205248700 \h 69 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003200340038003700300030000000 ​26.9.2. Challenges Ahead. PAGEREF _Toc205248701 \h 70 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003200340038003700300031000000 TOC \o "1-3" \h \z \u Chapter 27. OLED Encapsulation Materials and Technologies. PAGEREF _Toc205141436 \h 2 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003100340031003400330036000000 27.1. Introduction. PAGEREF _Toc205141437 \h 2 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003100340031003400330037000000 27.1.1. Degradation Mechanisms: How Moisture and Oxygen Attack OLEDs. PAGEREF _Toc205141438 \h 4 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003100340031003400330038000000 ​27.1.2. Key Requirements: WVTR and OTR Thresholds for Reliability​ PAGEREF _Toc205141439 \h 6 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003100340031003400330039000000 ​27.1.3. Challenge in OLED encapsulation. PAGEREF _Toc205141440 \h 7 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003100340031003400340030000000 27.1.4. OLED Encapsulation Market and Technological Drivers. PAGEREF _Toc205141441 \h 9 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003100340031003400340031000000 27.2. OLED Encapsulation Principles. PAGEREF _Toc205141442 \h 9 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003100340031003400340032000000 27.2.1. Classification of Encapsulation Principles. PAGEREF _Toc205141443 \h 10 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003100340031003400340033000000 27.2.2. Influence of Water and Oxygen on the Luminescence of OLED Display Panels  PAGEREF _Toc205141444 \h 10 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003100340031003400340034000000 27.2.3. The water permeability characteristics of organic/inorganic materials. PAGEREF _Toc205141445 \h 14 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003100340031003400340035000000 27.3. Encapsulation Materials. PAGEREF _Toc205141446 \h 15 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003100340031003400340036000000 27.3.1. Inorganic Materials. PAGEREF _Toc205141447 \h 16 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003100340031003400340037000000 27.3.2 Organic Materials​ PAGEREF _Toc205141448 \h 17 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003100340031003400340038000000 ​27.3.3 Composite Materials​ PAGEREF _Toc205141449 \h 18 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003100340031003400340039000000 27.4. Classification of Encapsulation Technologies. PAGEREF _Toc205141450 \h 19 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003100340031003400350030000000 27.4.1. Physical Encapsulation Technologies. PAGEREF _Toc205141451 \h 20 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003100340031003400350031000000 27.4.2 Chemical Encapsulation Technologies. PAGEREF _Toc205141452 \h 23 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003100340031003400350032000000 27.4.3 Composite Encapsulation Method. PAGEREF _Toc205141453 \h 25 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003100340031003400350033000000 27.5. Common OLED Encapsulation Technologies. PAGEREF _Toc205141454 \h 27 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003100340031003400350034000000 27.5.1. Edge Seal Encapsulation Technology. PAGEREF _Toc205141455 \h 28 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003100340031003400350035000000 27.5. 2 Frit Seal Encapsulation Technology. PAGEREF _Toc205141456 \h 31 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003100340031003400350036000000 27.5. 3. Dam and Fill Encapsulation Technology. PAGEREF _Toc205141457 \h 33 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003100340031003400350037000000 27.5. 4. Face Seal Encapsulation Technology. PAGEREF _Toc205141458 \h 35 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003100340031003400350038000000 27.6. Advanced OLED Encapsulation Technologies. PAGEREF _Toc205141459 \h 37 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003100340031003400350039000000 27.6.1. Thin-Film Encapsulation (TFE)​ PAGEREF _Toc205141460 \h 38 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003100340031003400360030000000 ​ 27.6.2. Rigid Encapsulation. PAGEREF _Toc205141461 \h 43 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003100340031003400360031000000 ​27.6.3. Advances of Different Encapsulation Technologies. PAGEREF _Toc205141462 \h 43 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003100340031003400360032000000 27.7. Challenges and Future Directions in OLED Encapsulation. PAGEREF _Toc205141463 \h 45 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003100340031003400360033000000 27.7.1 Current Limitations​ PAGEREF _Toc205141464 \h 45 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003100340031003400360034000000 ​27.7.2. Innovations and Future Directions​ PAGEREF _Toc205141465 \h 48 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003100340031003400360035000000 27.8. Research Institutions and Manufacturers of Commercial Packaging Materials. PAGEREF _Toc205141466 \h 54 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003100340031003400360036000000 27.9. Conclusion and Remarks. PAGEREF _Toc205141467 \h 57 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003100340031003400360037000000 References. PAGEREF _Toc205141468 \h 59 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003100340031003400360038000000 Chapter 28 ILLUMINATING THE FUTURE: THE TRANSFORMATIVE APPLICATIONS OF OLED TECHNOLOGY ACROSS INDUSTRIES 28.1 Introduction. PAGEREF _Toc209121232 \h 3 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300039003100320031003200330032000000 28.2 OLEDs in Consumer Electronics. PAGEREF _Toc209121233 \h 7 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300039003100320031003200330033000000 28.2.1 Smartphones and Tablets: The OLED Dominance. PAGEREF _Toc209121234 \h 7 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300039003100320031003200330034000000 28.2.2 Televisions and Monitors: The Visual Revolution. PAGEREF _Toc209121235 \h 8 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300039003100320031003200330035000000 28.2.3 Wearables and Flexible Displays: The Future Unfolds. PAGEREF _Toc209121236 \h 10 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300039003100320031003200330036000000 28.3 OLED in Automotive and Transportation Applications PAGEREF _Toc209121237 \h 12 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300039003100320031003200330037000000 28.3.1 OLED in Vehicle Displays: The Digital Cockpit Revolution. PAGEREF _Toc209121238 \h 12 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300039003100320031003200330038000000 28.3.2 OLED in Lighting Solutions: Beyond Illumination. PAGEREF _Toc209121239 \h 13 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300039003100320031003200330039000000 28.3.3 Aerospace and Public Transport: The Next Frontier PAGEREF _Toc209121240 \h 14 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300039003100320031003200340030000000 28.4 OLED in Healthcare and Biophotonics. PAGEREF _Toc209121241 \h 15 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300039003100320031003200340031000000 28.4.1 Medical Displays and Imaging: Precision Redefined. PAGEREF _Toc209121242 \h 16 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300039003100320031003200340032000000 28.4.2 Wearable Health Tech: The Skin as an Interface. PAGEREF _Toc209121243 \h 16 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300039003100320031003200340033000000 28.4.3 Photodynamic Therapy and Bio-Integrated Devices: Light as Medicine. PAGEREF _Toc209121244 \h 17 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300039003100320031003200340034000000 28.5. OLED in Architectural and Smart Lighting. PAGEREF _Toc209121245 \h 18 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300039003100320031003200340035000000 28.5.1 OLED in Interior Design: Beyond Conventional Lighting. PAGEREF _Toc209121246 \h 19 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300039003100320031003200340036000000 28.5.2. Energy-Efficient Lighting: OLED vs. Traditional LEDs. PAGEREF _Toc209121247 \h 20 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300039003100320031003200340037000000 28.5.3. Smart Cities and Public Spaces: OLED’s Urban Potential PAGEREF _Toc209121248 \h 20 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300039003100320031003200340038000000 28.6. OLED in Industrial and Military Applications. PAGEREF _Toc209121249 \h 21 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300039003100320031003200340039000000 28.6.1. OLED in Rugged and Flexible Displays: OLEDs in Harsh Environments. PAGEREF _Toc209121250 \h 22 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300039003100320031003200350030000000 28.6.2. OLED in Near-Infrared OLEDs in Sensing and Military Applications. PAGEREF _Toc209121251 \h 23 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300039003100320031003200350031000000 28.7. Emerging and Futuristic Applications. PAGEREF _Toc209121252 \h 24 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300039003100320031003200350032000000 28.7.1. OLEDs in Fashion and Wearable Art: The Fusion of Tech and Aesthetics. PAGEREF _Toc209121253 \h 24 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300039003100320031003200350033000000 28.7.2. Virtual and Augmented Reality and Visible Light Communication with OLED.. PAGEREF _Toc209121254 \h 25 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300039003100320031003200350034000000 28.7.3. Transparent and Solar-Integrated OLEDs: The Next Frontier PAGEREF _Toc209121255 \h 26 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300039003100320031003200350035000000 28.7.4. Radical-based OLED, crystalline OLED, single-crystal OLED.. PAGEREF _Toc209121256 \h 28 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300039003100320031003200350036000000 28.8. Challenges and Future Directions in OLED Technologies. PAGEREF _Toc209121257 \h 32 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300039003100320031003200350037000000 28.8.1. Technical Limitations: Bridging the Gap Between Innovation and Practicality. PAGEREF _Toc209121258 \h 33 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300039003100320031003200350038000000 28.8.2. Sustainability and Recycling: Toward a Greener OLED Ecosystem.. PAGEREF _Toc209121259 \h 34 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300039003100320031003200350039000000 28.8.3. The Road Ahead: Next-Gen OLED Hybrids and Micro-Displays. PAGEREF _Toc209121260 \h 35 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300039003100320031003200360030000000 28.9. Conclusion: The Bright Future of OLEDs. PAGEREF _Toc209121261 \h 36 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300039003100320031003200360031000000 28.10 References. PAGEREF _Toc209121262 \h 37 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300039003100320031003200360032000000 1. Introduction: The Diversification of OLED Materials. PAGEREF _Toc213360853 \h 2 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200310033003300360030003800350033000000 1.1  Limitations of Traditional OLED Materials. PAGEREF _Toc213360854 \h 4 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200310033003300360030003800350034000000 1.2  Emergence of Novel Material Systems. PAGEREF _Toc213360855 \h 6 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200310033003300360030003800350035000000 2. Exploration of Novel Material Systems. PAGEREF _Toc213360856 \h 8 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200310033003300360030003800350036000000 2.1 Radical-Based OLEDs. PAGEREF _Toc213360857 \h 8 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200310033003300360030003800350037000000 2.1.1 Characteristics and Advantages of Radical Materials. PAGEREF _Toc213360858 \h 8 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200310033003300360030003800350038000000 2.1.2 Fabrication and Performance of Radical-Based OLEDs. PAGEREF _Toc213360859 \h 15 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200310033003300360030003800350039000000 2.1.3 Prospects and Challenges. PAGEREF _Toc213360860 \h 18 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200310033003300360030003800360030000000 2.2 Polycrystalline OLEDs. PAGEREF _Toc213360861 \h 19 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200310033003300360030003800360031000000 2.2.1 Advantages of Polycrystalline Structure. PAGEREF _Toc213360862 \h 20 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200310033003300360030003800360032000000 2.2.2 Fabrication Process and Performance Optimization. PAGEREF _Toc213360863 \h 23 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200310033003300360030003800360033000000 2.2.3 Applications in High-Efficiency Devices. PAGEREF _Toc213360864 \h 24 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200310033003300360030003800360034000000 2.3 Single-Crystal OLEDs. PAGEREF _Toc213360865 \h 26 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200310033003300360030003800360035000000 2.3.1 Superiority of Single-Crystal Structure. PAGEREF _Toc213360866 \h 27 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200310033003300360030003800360036000000 2.3.2 Fabrication Techniques and Challenges. PAGEREF _Toc213360867 \h 31 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200310033003300360030003800360037000000 2.3.3 Applications in High-Performance Devices. PAGEREF _Toc213360868 \h 32 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200310033003300360030003800360038000000 2.3.4 Comparison of Free Radicals, Single Crystals, and Polycrystals. PAGEREF _Toc213360869 \h 34 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200310033003300360030003800360039000000 3. Novel Light-emitting Device Structures. PAGEREF _Toc213360870 \h 35 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200310033003300360030003800370030000000 3.1 Planar Alternating-Current Electroluminescent (AC-EL) Devices. PAGEREF _Toc213360871 \h 35 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200310033003300360030003800370031000000 3.2 Organic Light-Emitting Tetrodes. PAGEREF _Toc213360872 \h 38 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200310033003300360030003800370032000000 4. Performance and Application Prospects. PAGEREF _Toc213360873 \h 41 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200310033003300360030003800370033000000 4.1 Radical OLEDs: Advantages, Applications, and Outlook. PAGEREF _Toc213360874 \h 41 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200310033003300360030003800370034000000 4.2 Polycrystalline OLEDs: Advantages, Applications, and Outlook. PAGEREF _Toc213360875 \h 42 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200310033003300360030003800370035000000 4.3 Single-Crystal OLEDs: Advantages, Applications, and Future Directions. PAGEREF _Toc213360876 \h 42 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200310033003300360030003800370036000000 4.4 AC-EL Devices. PAGEREF _Toc213360877 \h 43 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200310033003300360030003800370037000000 5. Conclusion. PAGEREF _Toc213360878 \h 44 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200310033003300360030003800370038000000 Reference  PAGEREF _Toc213360879 \h 45 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200310033003300360030003800370039000000 ​26.9.3. Strategic Partnerships: PAGEREF _Toc205248702 \h 70 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003200340038003700300032000000 References  PAGEREF _Toc205248703 \h 70 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F0054006F0063003200300035003200340038003700300033000000