Hong Meng, PhD, is Professor at the School of Advanced Materials, Peking University Shenzhen Graduate School, China. He has been working in the field of organic electronics for more than 30 years.

• Preface xi1 Structure and Physical Properties of Metal Halide Perovskites 11.1 Crystal Structure of Perovskite Materials 11.2 Exciton Effects in Perovskite Materials 21.2.1 Definition of an Exciton 21.2.2 Self-Trapping Excitons in Perovskite Materials 31.3 Size Effect of Perovskite Materials 51.4 Luminescence Properties of Perovskite Materials 71.4.1 Photon Generation in Perovskite Materials 81.4.2 Photophysical Processes and Efficiency Calculations of Perovskite Luminescence 101.4.3 Non-radiative Combination Mechanisms at Surfaces and Interfaces 131.5 Factors Influencing the Efficiency of Perovskite Light Emitting Diodes 161.5.1 Device Structure of the Perovskite Light Emitting Diode 161.5.2 Physical Parameters of Perovskite Light-Emitting Diodes 181.5.3 Device Performance Development of Perovskite Light-Emitting Diodes 201.6 Summary 232 Synthesis and Preparation of Perovskite Materials 352.1 Introduction 352.2 Perovskite Materials Structures 362.2.1 3D Halide Perovskite Materials for Light-Emitting Diodes 362.2.2 Layered Halide Perovskite Materials 362.2.3 Halide Perovskite Quantum Dots/Nanocrystals 402.2.4 Commercial Prospects of Perovskite Materials 432.3 Preparation of Perovskite Nanomaterials 462.3.1 Mechanochemical Method 462.3.2 Ultrasonic Method 472.3.3 Microwave Method 492.3.4 Solvent Heat Method 502.3.5 Thermal Injection Method 512.3.6 Ligand-Assisted Reprecipitation 602.3.7 Ion Exchange Method 672.3.8 Laser Etching Method 682.4 Processing Technology for Large-Area Perovskite Films 692.4.1 Spin Coating Method 692.4.2 Vacuum Thermal Vapor Deposition Method 702.4.3 Printing Method 712.4.4 Vapor -Phase Deposition Method 712.4.5 Spraying Method 742.4.6 Template Method 752.4.7 Non-Template Method 752.5 Conclusion and Outlook 763 Near-Infrared Perovskite Light-Emitting Devices 833.1 Introduction 833.2 Progress in Near-Infrared Perovskite Luminescence Materials 843.3 Near-Infrared Perovskite Luminescent Materials 863.3.1 Methylamine Lead Iodide (MAPbI3) 863.3.2 NIR-Emitting Materials Based on Perovskite 883.4 Strategies to Improve the Performance of NIR Perovskite Devices 903.4.1 NIR Perovskite Material Optimization 913.4.1.1 Near-InfraredWavelength Adjustment 913.4.1.2 Multiple QuantumWell Structure 943.4.1.3 Molecular Passivation 953.4.2 Device Structure Optimization 963.5 Conclusion and Outlook 984 Perovskite Red Light-Emitting Materials and Devices 1034.1 The Development History of Perovskite Red Light-Emitting Diodes 1034.2 Red Emission Perovskite Materials 1054.2.1 Typical Red Emission Perovskite Material CsPbI3 1054.2.2 Other Red Emission Perovskite Materials 1074.2.2.1 Other ABX3 and Hybridized ABX3-Type Materials 1074.2.2.2 Double Perovskite 1104.2.3 Red Emission Perovskite Synthesis 1114.2.3.1 Synthesis of Nanocrystals 1114.2.3.2 Synthesis of Quasi-Two-Dimensional Films 1124.2.4 Optimization Strategies of Red Perovskite Materials 1134.2.4.1 Doping 1134.2.4.2 Surface Passivation 1144.2.4.3 Multiple QuantumWell Structure 1154.2.4.4 Ligand Engineering 1164.2.4.5 Additive Engineering 1174.3 Perovskite Red Light-Emitting Diodes 1174.3.1 Device Structure and Common Materials for Each Functional Layer 1174.3.2 Device Optimization Strategy 1184.3.2.1 Energy Level Regulation 1194.3.2.2 Light Extraction Technology 1194.3.2.3 Interface Treatment Method 1194.4 Conclusion and Outlook 1205 Perovskite Green Light-Emitting Materials and Devices 1295.1 History of Green Perovskite Light-Emitting Diodes 1295.2 Green Light Perovskite Materials 1325.2.1 Pure Inorganic Perovskite Materials 1345.2.2 Organic–Inorganic Hybrid Perovskite Materials 1365.2.3 Synthesis of Perovskite Green Light-Emitting Materials 1375.3 Development of Green Perovskite Light-Emitting Diodes 1405.3.1 Structure of Green Perovskite Light-Emitting Diode Devices 1405.3.2 Quantum Dot Green Perovskite Light-Emitting Diodes 1415.3.3 Nanocrystalline Green Perovskite Light-Emitting Diodes 1425.3.4 Quasi-2D Ruddlesden–Popper Green Perovskite Light-Emitting Diodes 1465.4 Factors Affecting the External Quantum Efficiency of Perovskite Green Light-Emitting Diodes 1465.4.1 Aspects of Materials 1465.4.2 Aspects of the Device Structure 1475.5 Strategies for Improving the External Quantum Efficiency of Green Perovskite Light-Emitting Diodes 1475.5.1 Ligand Engineering 1475.5.2 Crystal Engineering 1505.5.3 Surface Engineering 1515.5.4 Passivation Engineering 1535.5.5 Optimization of the Device Structure 1555.6 Other Properties of Green Perovskite Light-Emitting Diodes 1585.7 Conclusion and Outlook 1616 Blue Perovskite Light-emitting Materials and Devices 1696.1 Technology Development of Blue Perovskite Light-emitting Diodes 1696.2 Blueshift Strategy 1716.3 Perovskite Blue Light-emitting Materials 1756.3.1 Perovskite Blue Light-emitting Materials with a Quasi-two-dimensional Structure 1756.3.1.1 Development of New Bulky Cations 1766.3.1.2 Mixing of Bulky Cations 1816.3.1.3 Cationic Doping 1816.3.2 Blue Light Perovskite Nanocrystals or Quantum Dot Materials 1836.4 Synthesis and Use of New Long-Chain Ligands 1836.5 Surface Modification of Nanostructures 1846.6 Optimization of the Internal Structure 1866.7 Process for the Preparation of Blue Light-Emitting Layers 1906.7.1 Preparation of Three-Dimensional and Quasi-Two-Dimensional Perovskite Films 1906.7.2 Preparation of Nano-Microcrystalline Precursors 1916.8 Device Performance Optimization and Interface Engineering 1916.8.1 Passivation of Film Defects 1916.8.2 Selection and Optimization of Hole and Electron Injection Layers 1926.8.3 Interface Engineering 1936.9 Optimization of Device Stability 1956.9.1 Lifetime of Perovskite Blue Light-emitting Diodes 1956.9.2 Optimization of Efficiency Stability in Perovskite Light-emitting Diodes 1966.9.3 Light Color Stability Optimization 1986.10 Conclusion and Outlook 1997 Effect of Metal Ion Doping on Perovskite Light-Emitting Materials 2057.1 Metal Ion Doping Effect 2077.1.1 Effect of A-site Metal Ion Doping on Perovskite Materials 2087.1.2 Effect of B-site Metal Ion Doping on Perovskite Materials 2107.2 Metal Ion-Doped Materials and Devices 2127.2.1 Near-infrared Optical Perovskite Materials 2127.2.2 Red Light Perovskite Materials 2147.2.3 Green Light Perovskite Materials 2167.2.4 Blue-Light Perovskite Materials 2187.3 Metal Ion Doping Methods 2207.3.1 Post-synthesis Ion Exchange Methods 2207.3.2 Colloidal Synthesis Methods 2217.3.3 The Thermal Injection Methods 2237.3.4 High Temperature Solid-state Synthesis Methods 2237.4 Conclusion and Outlook 2248 Non-lead Metal Halide Perovskite Materials 2318.1 Development History of Non-lead Blue Perovskite Materials 2318.2 Preparation of Non-lead Metal Halide Materials 2348.3 Types of Non-lead Metal Halide Materials 2368.3.1 Tin-Based Perovskites Materials 2368.3.2 Bismuth-Based Metal Halide Materials 2388.3.3 Antimony-Based Metal Halide Materials 2418.3.4 Copper-Based Metal Halide Materials 2418.3.5 Europium-Based Metal Halide Materials 2438.3.6 Bimetallic Cationic Halide Perovskites Materials 2438.4 Methods for Optimizing the Fluorescence Quantum Efficiency of Non-lead Metal Halide Materials 2478.4.1 Surface Passivation 2478.4.2 Selection of Solvents and Undesirable Solvents 2488.4.3 Doping 2488.5 Conclusion and Outlook 2519 Perovskite White Light-emitting Materials and Devices 2559.1 Background ofWPeLED 2559.2 Down-conversion Method 2579.3 Full Electroluminescent PeLEDs 2619.3.1 Yellow Perovskite Light-emitting Diodes 2619.3.1.1 Zero-dimensional Sn-doped Halide Perovskites 2619.3.1.2 2D (C18H35NH3)2SnBr4 Perovskite 2639.3.1.3 Colloidal Undoped and Double-doped Cs2AgInCl6 Nanocrystals 2639.3.1.4 Introducing Separated Emitting Centers 2649.3.2 Progress in the Research of Sky-Blue Perovskite Light-emitting Diodes 2669.4 Single White Light Perovskite Materials and Self-trapped Excitons 2719.4.1 Single White Light Perovskite Materials 2719.4.1.1 (110) Perovskite with Corrugated Inorganic Layers 2719.4.1.2 (001) Perovskite with Flat Inorganic Layers 2749.4.2 Self-trapped Excitons 2749.5 Perovskite–Organic Coupling White PeLEDs 2789.6 Others 2819.7 Conclusion and Outlook 28110 Electron and Hole Transport Materials 28510.1 Background of Charge Transport Materials 28510.1.1 Charge Transport of Metal Halide Perovskite Materials 28610.1.2 Charge Transport Materials in PeLED 28810.2 Electron Transport Materials in PeLEDs 28910.2.1 Inorganic Oxides Electron Transport Materials 28910.2.2 Inorganically Doped Electron Transport Materials 29210.2.3 Organic Monolayer Electron Transport Materials 29210.2.4 Organic Multilayer Electron Transport Materials 29210.2.5 Doped Organic Electron Transport Materials 29310.2.6 Organic–Inorganic Hybrid Electron Transport Materials 29410.3 Hole Transport Materials in PeLEDs 29410.4 Progress in the Study of Hole Transport Layers and Hole Injection Layers n Perovskite Light Emitting Diodes 29510.4.1 PVK-Doped TPD, TCTA 29610.4.2 PEDOT:PSS After Methanol Treatment 29710.4.3 TB(MA) Instead of PEDOT:PSS 29910.4.4 PSS-Doped Na 30010.4.5 PVK-Doped NiOx 30010.4.6 Quantum Dot Perovskite Light Emitting Diodes: PVK-Doped PTAA 30010.4.7 PVK Blended with PBD 30110.4.8 Double HTLs with PVK and TFB 30210.4.9 Polyfluorenylbenzene Anion-Conjugated Polyelectrolytes with Counter Ions 30310.5 Conclusion and Outlook 30511 Stability of Perovskite Light-emitting Diodes 31111.1 Sources of Instability in Metal Halide Perovskites and Perovskite Light-emitting Diodes 31111.1.1 Intrinsic Instability of PeLEDs 31211.1.2 Extrinsic Instability of PeLEDs 31311.2 Analysis of the Current Stability of Perovskite Light-emitting Diodes 31411.3 Factors Affecting Efficiency Roll-off 31511.4 Strategies for Dealing with Efficiency Roll-off 31911.4.1 Perovskite Structure Modulation 31911.4.2 Hole Injection Layer Modulation 32111.4.3 Electron Injection Layer Modulation 32311.5 Conclusion and Outlook 32612 Perovskite Materials for Laser Applications 33112.1 Physics Principles of Laser 33112.2 Perovskite Laser for Different Morphologies 33512.2.1 Laser of Perovskite Films 33512.2.2 Laser of Perovskite Nanowires 33712.2.3 Laser of Perovskite Nanoplates and Microplates 33912.2.4 Laser of Perovskite Nanocrystals or Quantum Dots 34112.3 Conclusion and Outlook 342References 343Index 349

Hong Meng, PhD, is Professor at the School of Advanced Materials, Peking University Shenzhen Graduate School, China. He has been working in the field of organic electronics for more than 30 years.

• Preface xi1 Structure and Physical Properties of Metal Halide Perovskites 11.1 Crystal Structure of Perovskite Materials 11.2 Exciton Effects in Perovskite Materials 21.2.1 Definition of an Exciton 21.2.2 Self-Trapping Excitons in Perovskite Materials 31.3 Size Effect of Perovskite Materials 51.4 Luminescence Properties of Perovskite Materials 71.4.1 Photon Generation in Perovskite Materials 81.4.2 Photophysical Processes and Efficiency Calculations of Perovskite Luminescence 101.4.3 Non-radiative Combination Mechanisms at Surfaces and Interfaces 131.5 Factors Influencing the Efficiency of Perovskite Light Emitting Diodes 161.5.1 Device Structure of the Perovskite Light Emitting Diode 161.5.2 Physical Parameters of Perovskite Light-Emitting Diodes 181.5.3 Device Performance Development of Perovskite Light-Emitting Diodes 201.6 Summary 232 Synthesis and Preparation of Perovskite Materials 352.1 Introduction 352.2 Perovskite Materials Structures 362.2.1 3D Halide Perovskite Materials for Light-Emitting Diodes 362.2.2 Layered Halide Perovskite Materials 362.2.3 Halide Perovskite Quantum Dots/Nanocrystals 402.2.4 Commercial Prospects of Perovskite Materials 432.3 Preparation of Perovskite Nanomaterials 462.3.1 Mechanochemical Method 462.3.2 Ultrasonic Method 472.3.3 Microwave Method 492.3.4 Solvent Heat Method 502.3.5 Thermal Injection Method 512.3.6 Ligand-Assisted Reprecipitation 602.3.7 Ion Exchange Method 672.3.8 Laser Etching Method 682.4 Processing Technology for Large-Area Perovskite Films 692.4.1 Spin Coating Method 692.4.2 Vacuum Thermal Vapor Deposition Method 702.4.3 Printing Method 712.4.4 Vapor -Phase Deposition Method 712.4.5 Spraying Method 742.4.6 Template Method 752.4.7 Non-Template Method 752.5 Conclusion and Outlook 763 Near-Infrared Perovskite Light-Emitting Devices 833.1 Introduction 833.2 Progress in Near-Infrared Perovskite Luminescence Materials 843.3 Near-Infrared Perovskite Luminescent Materials 863.3.1 Methylamine Lead Iodide (MAPbI3) 863.3.2 NIR-Emitting Materials Based on Perovskite 883.4 Strategies to Improve the Performance of NIR Perovskite Devices 903.4.1 NIR Perovskite Material Optimization 913.4.1.1 Near-InfraredWavelength Adjustment 913.4.1.2 Multiple QuantumWell Structure 943.4.1.3 Molecular Passivation 953.4.2 Device Structure Optimization 963.5 Conclusion and Outlook 984 Perovskite Red Light-Emitting Materials and Devices 1034.1 The Development History of Perovskite Red Light-Emitting Diodes 1034.2 Red Emission Perovskite Materials 1054.2.1 Typical Red Emission Perovskite Material CsPbI3 1054.2.2 Other Red Emission Perovskite Materials 1074.2.2.1 Other ABX3 and Hybridized ABX3-Type Materials 1074.2.2.2 Double Perovskite 1104.2.3 Red Emission Perovskite Synthesis 1114.2.3.1 Synthesis of Nanocrystals 1114.2.3.2 Synthesis of Quasi-Two-Dimensional Films 1124.2.4 Optimization Strategies of Red Perovskite Materials 1134.2.4.1 Doping 1134.2.4.2 Surface Passivation 1144.2.4.3 Multiple QuantumWell Structure 1154.2.4.4 Ligand Engineering 1164.2.4.5 Additive Engineering 1174.3 Perovskite Red Light-Emitting Diodes 1174.3.1 Device Structure and Common Materials for Each Functional Layer 1174.3.2 Device Optimization Strategy 1184.3.2.1 Energy Level Regulation 1194.3.2.2 Light Extraction Technology 1194.3.2.3 Interface Treatment Method 1194.4 Conclusion and Outlook 1205 Perovskite Green Light-Emitting Materials and Devices 1295.1 History of Green Perovskite Light-Emitting Diodes 1295.2 Green Light Perovskite Materials 1325.2.1 Pure Inorganic Perovskite Materials 1345.2.2 Organic–Inorganic Hybrid Perovskite Materials 1365.2.3 Synthesis of Perovskite Green Light-Emitting Materials 1375.3 Development of Green Perovskite Light-Emitting Diodes 1405.3.1 Structure of Green Perovskite Light-Emitting Diode Devices 1405.3.2 Quantum Dot Green Perovskite Light-Emitting Diodes 1415.3.3 Nanocrystalline Green Perovskite Light-Emitting Diodes 1425.3.4 Quasi-2D Ruddlesden–Popper Green Perovskite Light-Emitting Diodes 1465.4 Factors Affecting the External Quantum Efficiency of Perovskite Green Light-Emitting Diodes 1465.4.1 Aspects of Materials 1465.4.2 Aspects of the Device Structure 1475.5 Strategies for Improving the External Quantum Efficiency of Green Perovskite Light-Emitting Diodes 1475.5.1 Ligand Engineering 1475.5.2 Crystal Engineering 1505.5.3 Surface Engineering 1515.5.4 Passivation Engineering 1535.5.5 Optimization of the Device Structure 1555.6 Other Properties of Green Perovskite Light-Emitting Diodes 1585.7 Conclusion and Outlook 1616 Blue Perovskite Light-emitting Materials and Devices 1696.1 Technology Development of Blue Perovskite Light-emitting Diodes 1696.2 Blueshift Strategy 1716.3 Perovskite Blue Light-emitting Materials 1756.3.1 Perovskite Blue Light-emitting Materials with a Quasi-two-dimensional Structure 1756.3.1.1 Development of New Bulky Cations 1766.3.1.2 Mixing of Bulky Cations 1816.3.1.3 Cationic Doping 1816.3.2 Blue Light Perovskite Nanocrystals or Quantum Dot Materials 1836.4 Synthesis and Use of New Long-Chain Ligands 1836.5 Surface Modification of Nanostructures 1846.6 Optimization of the Internal Structure 1866.7 Process for the Preparation of Blue Light-Emitting Layers 1906.7.1 Preparation of Three-Dimensional and Quasi-Two-Dimensional Perovskite Films 1906.7.2 Preparation of Nano-Microcrystalline Precursors 1916.8 Device Performance Optimization and Interface Engineering 1916.8.1 Passivation of Film Defects 1916.8.2 Selection and Optimization of Hole and Electron Injection Layers 1926.8.3 Interface Engineering 1936.9 Optimization of Device Stability 1956.9.1 Lifetime of Perovskite Blue Light-emitting Diodes 1956.9.2 Optimization of Efficiency Stability in Perovskite Light-emitting Diodes 1966.9.3 Light Color Stability Optimization 1986.10 Conclusion and Outlook 1997 Effect of Metal Ion Doping on Perovskite Light-Emitting Materials 2057.1 Metal Ion Doping Effect 2077.1.1 Effect of A-site Metal Ion Doping on Perovskite Materials 2087.1.2 Effect of B-site Metal Ion Doping on Perovskite Materials 2107.2 Metal Ion-Doped Materials and Devices 2127.2.1 Near-infrared Optical Perovskite Materials 2127.2.2 Red Light Perovskite Materials 2147.2.3 Green Light Perovskite Materials 2167.2.4 Blue-Light Perovskite Materials 2187.3 Metal Ion Doping Methods 2207.3.1 Post-synthesis Ion Exchange Methods 2207.3.2 Colloidal Synthesis Methods 2217.3.3 The Thermal Injection Methods 2237.3.4 High Temperature Solid-state Synthesis Methods 2237.4 Conclusion and Outlook 2248 Non-lead Metal Halide Perovskite Materials 2318.1 Development History of Non-lead Blue Perovskite Materials 2318.2 Preparation of Non-lead Metal Halide Materials 2348.3 Types of Non-lead Metal Halide Materials 2368.3.1 Tin-Based Perovskites Materials 2368.3.2 Bismuth-Based Metal Halide Materials 2388.3.3 Antimony-Based Metal Halide Materials 2418.3.4 Copper-Based Metal Halide Materials 2418.3.5 Europium-Based Metal Halide Materials 2438.3.6 Bimetallic Cationic Halide Perovskites Materials 2438.4 Methods for Optimizing the Fluorescence Quantum Efficiency of Non-lead Metal Halide Materials 2478.4.1 Surface Passivation 2478.4.2 Selection of Solvents and Undesirable Solvents 2488.4.3 Doping 2488.5 Conclusion and Outlook 2519 Perovskite White Light-emitting Materials and Devices 2559.1 Background ofWPeLED 2559.2 Down-conversion Method 2579.3 Full Electroluminescent PeLEDs 2619.3.1 Yellow Perovskite Light-emitting Diodes 2619.3.1.1 Zero-dimensional Sn-doped Halide Perovskites 2619.3.1.2 2D (C18H35NH3)2SnBr4 Perovskite 2639.3.1.3 Colloidal Undoped and Double-doped Cs2AgInCl6 Nanocrystals 2639.3.1.4 Introducing Separated Emitting Centers 2649.3.2 Progress in the Research of Sky-Blue Perovskite Light-emitting Diodes 2669.4 Single White Light Perovskite Materials and Self-trapped Excitons 2719.4.1 Single White Light Perovskite Materials 2719.4.1.1 (110) Perovskite with Corrugated Inorganic Layers 2719.4.1.2 (001) Perovskite with Flat Inorganic Layers 2749.4.2 Self-trapped Excitons 2749.5 Perovskite–Organic Coupling White PeLEDs 2789.6 Others 2819.7 Conclusion and Outlook 28110 Electron and Hole Transport Materials 28510.1 Background of Charge Transport Materials 28510.1.1 Charge Transport of Metal Halide Perovskite Materials 28610.1.2 Charge Transport Materials in PeLED 28810.2 Electron Transport Materials in PeLEDs 28910.2.1 Inorganic Oxides Electron Transport Materials 28910.2.2 Inorganically Doped Electron Transport Materials 29210.2.3 Organic Monolayer Electron Transport Materials 29210.2.4 Organic Multilayer Electron Transport Materials 29210.2.5 Doped Organic Electron Transport Materials 29310.2.6 Organic–Inorganic Hybrid Electron Transport Materials 29410.3 Hole Transport Materials in PeLEDs 29410.4 Progress in the Study of Hole Transport Layers and Hole Injection Layers n Perovskite Light Emitting Diodes 29510.4.1 PVK-Doped TPD, TCTA 29610.4.2 PEDOT:PSS After Methanol Treatment 29710.4.3 TB(MA) Instead of PEDOT:PSS 29910.4.4 PSS-Doped Na 30010.4.5 PVK-Doped NiOx 30010.4.6 Quantum Dot Perovskite Light Emitting Diodes: PVK-Doped PTAA 30010.4.7 PVK Blended with PBD 30110.4.8 Double HTLs with PVK and TFB 30210.4.9 Polyfluorenylbenzene Anion-Conjugated Polyelectrolytes with Counter Ions 30310.5 Conclusion and Outlook 30511 Stability of Perovskite Light-emitting Diodes 31111.1 Sources of Instability in Metal Halide Perovskites and Perovskite Light-emitting Diodes 31111.1.1 Intrinsic Instability of PeLEDs 31211.1.2 Extrinsic Instability of PeLEDs 31311.2 Analysis of the Current Stability of Perovskite Light-emitting Diodes 31411.3 Factors Affecting Efficiency Roll-off 31511.4 Strategies for Dealing with Efficiency Roll-off 31911.4.1 Perovskite Structure Modulation 31911.4.2 Hole Injection Layer Modulation 32111.4.3 Electron Injection Layer Modulation 32311.5 Conclusion and Outlook 32612 Perovskite Materials for Laser Applications 33112.1 Physics Principles of Laser 33112.2 Perovskite Laser for Different Morphologies 33512.2.1 Laser of Perovskite Films 33512.2.2 Laser of Perovskite Nanowires 33712.2.3 Laser of Perovskite Nanoplates and Microplates 33912.2.4 Laser of Perovskite Nanocrystals or Quantum Dots 34112.3 Conclusion and Outlook 342References 343Index 349

Hong Meng, PhD, is Professor at the School of Advanced Materials, Peking University Shenzhen Graduate School, China. He has been working in the field of organic electronics for more than 30 years.

• Preface xi1 Structure and Physical Properties of Metal Halide Perovskites 11.1 Crystal Structure of Perovskite Materials 11.2 Exciton Effects in Perovskite Materials 21.2.1 Definition of an Exciton 21.2.2 Self-Trapping Excitons in Perovskite Materials 31.3 Size Effect of Perovskite Materials 51.4 Luminescence Properties of Perovskite Materials 71.4.1 Photon Generation in Perovskite Materials 81.4.2 Photophysical Processes and Efficiency Calculations of Perovskite Luminescence 101.4.3 Non-radiative Combination Mechanisms at Surfaces and Interfaces 131.5 Factors Influencing the Efficiency of Perovskite Light Emitting Diodes 161.5.1 Device Structure of the Perovskite Light Emitting Diode 161.5.2 Physical Parameters of Perovskite Light-Emitting Diodes 181.5.3 Device Performance Development of Perovskite Light-Emitting Diodes 201.6 Summary 232 Synthesis and Preparation of Perovskite Materials 352.1 Introduction 352.2 Perovskite Materials Structures 362.2.1 3D Halide Perovskite Materials for Light-Emitting Diodes 362.2.2 Layered Halide Perovskite Materials 362.2.3 Halide Perovskite Quantum Dots/Nanocrystals 402.2.4 Commercial Prospects of Perovskite Materials 432.3 Preparation of Perovskite Nanomaterials 462.3.1 Mechanochemical Method 462.3.2 Ultrasonic Method 472.3.3 Microwave Method 492.3.4 Solvent Heat Method 502.3.5 Thermal Injection Method 512.3.6 Ligand-Assisted Reprecipitation 602.3.7 Ion Exchange Method 672.3.8 Laser Etching Method 682.4 Processing Technology for Large-Area Perovskite Films 692.4.1 Spin Coating Method 692.4.2 Vacuum Thermal Vapor Deposition Method 702.4.3 Printing Method 712.4.4 Vapor -Phase Deposition Method 712.4.5 Spraying Method 742.4.6 Template Method 752.4.7 Non-Template Method 752.5 Conclusion and Outlook 763 Near-Infrared Perovskite Light-Emitting Devices 833.1 Introduction 833.2 Progress in Near-Infrared Perovskite Luminescence Materials 843.3 Near-Infrared Perovskite Luminescent Materials 863.3.1 Methylamine Lead Iodide (MAPbI3) 863.3.2 NIR-Emitting Materials Based on Perovskite 883.4 Strategies to Improve the Performance of NIR Perovskite Devices 903.4.1 NIR Perovskite Material Optimization 913.4.1.1 Near-InfraredWavelength Adjustment 913.4.1.2 Multiple QuantumWell Structure 943.4.1.3 Molecular Passivation 953.4.2 Device Structure Optimization 963.5 Conclusion and Outlook 984 Perovskite Red Light-Emitting Materials and Devices 1034.1 The Development History of Perovskite Red Light-Emitting Diodes 1034.2 Red Emission Perovskite Materials 1054.2.1 Typical Red Emission Perovskite Material CsPbI3 1054.2.2 Other Red Emission Perovskite Materials 1074.2.2.1 Other ABX3 and Hybridized ABX3-Type Materials 1074.2.2.2 Double Perovskite 1104.2.3 Red Emission Perovskite Synthesis 1114.2.3.1 Synthesis of Nanocrystals 1114.2.3.2 Synthesis of Quasi-Two-Dimensional Films 1124.2.4 Optimization Strategies of Red Perovskite Materials 1134.2.4.1 Doping 1134.2.4.2 Surface Passivation 1144.2.4.3 Multiple QuantumWell Structure 1154.2.4.4 Ligand Engineering 1164.2.4.5 Additive Engineering 1174.3 Perovskite Red Light-Emitting Diodes 1174.3.1 Device Structure and Common Materials for Each Functional Layer 1174.3.2 Device Optimization Strategy 1184.3.2.1 Energy Level Regulation 1194.3.2.2 Light Extraction Technology 1194.3.2.3 Interface Treatment Method 1194.4 Conclusion and Outlook 1205 Perovskite Green Light-Emitting Materials and Devices 1295.1 History of Green Perovskite Light-Emitting Diodes 1295.2 Green Light Perovskite Materials 1325.2.1 Pure Inorganic Perovskite Materials 1345.2.2 Organic–Inorganic Hybrid Perovskite Materials 1365.2.3 Synthesis of Perovskite Green Light-Emitting Materials 1375.3 Development of Green Perovskite Light-Emitting Diodes 1405.3.1 Structure of Green Perovskite Light-Emitting Diode Devices 1405.3.2 Quantum Dot Green Perovskite Light-Emitting Diodes 1415.3.3 Nanocrystalline Green Perovskite Light-Emitting Diodes 1425.3.4 Quasi-2D Ruddlesden–Popper Green Perovskite Light-Emitting Diodes 1465.4 Factors Affecting the External Quantum Efficiency of Perovskite Green Light-Emitting Diodes 1465.4.1 Aspects of Materials 1465.4.2 Aspects of the Device Structure 1475.5 Strategies for Improving the External Quantum Efficiency of Green Perovskite Light-Emitting Diodes 1475.5.1 Ligand Engineering 1475.5.2 Crystal Engineering 1505.5.3 Surface Engineering 1515.5.4 Passivation Engineering 1535.5.5 Optimization of the Device Structure 1555.6 Other Properties of Green Perovskite Light-Emitting Diodes 1585.7 Conclusion and Outlook 1616 Blue Perovskite Light-emitting Materials and Devices 1696.1 Technology Development of Blue Perovskite Light-emitting Diodes 1696.2 Blueshift Strategy 1716.3 Perovskite Blue Light-emitting Materials 1756.3.1 Perovskite Blue Light-emitting Materials with a Quasi-two-dimensional Structure 1756.3.1.1 Development of New Bulky Cations 1766.3.1.2 Mixing of Bulky Cations 1816.3.1.3 Cationic Doping 1816.3.2 Blue Light Perovskite Nanocrystals or Quantum Dot Materials 1836.4 Synthesis and Use of New Long-Chain Ligands 1836.5 Surface Modification of Nanostructures 1846.6 Optimization of the Internal Structure 1866.7 Process for the Preparation of Blue Light-Emitting Layers 1906.7.1 Preparation of Three-Dimensional and Quasi-Two-Dimensional Perovskite Films 1906.7.2 Preparation of Nano-Microcrystalline Precursors 1916.8 Device Performance Optimization and Interface Engineering 1916.8.1 Passivation of Film Defects 1916.8.2 Selection and Optimization of Hole and Electron Injection Layers 1926.8.3 Interface Engineering 1936.9 Optimization of Device Stability 1956.9.1 Lifetime of Perovskite Blue Light-emitting Diodes 1956.9.2 Optimization of Efficiency Stability in Perovskite Light-emitting Diodes 1966.9.3 Light Color Stability Optimization 1986.10 Conclusion and Outlook 1997 Effect of Metal Ion Doping on Perovskite Light-Emitting Materials 2057.1 Metal Ion Doping Effect 2077.1.1 Effect of A-site Metal Ion Doping on Perovskite Materials 2087.1.2 Effect of B-site Metal Ion Doping on Perovskite Materials 2107.2 Metal Ion-Doped Materials and Devices 2127.2.1 Near-infrared Optical Perovskite Materials 2127.2.2 Red Light Perovskite Materials 2147.2.3 Green Light Perovskite Materials 2167.2.4 Blue-Light Perovskite Materials 2187.3 Metal Ion Doping Methods 2207.3.1 Post-synthesis Ion Exchange Methods 2207.3.2 Colloidal Synthesis Methods 2217.3.3 The Thermal Injection Methods 2237.3.4 High Temperature Solid-state Synthesis Methods 2237.4 Conclusion and Outlook 2248 Non-lead Metal Halide Perovskite Materials 2318.1 Development History of Non-lead Blue Perovskite Materials 2318.2 Preparation of Non-lead Metal Halide Materials 2348.3 Types of Non-lead Metal Halide Materials 2368.3.1 Tin-Based Perovskites Materials 2368.3.2 Bismuth-Based Metal Halide Materials 2388.3.3 Antimony-Based Metal Halide Materials 2418.3.4 Copper-Based Metal Halide Materials 2418.3.5 Europium-Based Metal Halide Materials 2438.3.6 Bimetallic Cationic Halide Perovskites Materials 2438.4 Methods for Optimizing the Fluorescence Quantum Efficiency of Non-lead Metal Halide Materials 2478.4.1 Surface Passivation 2478.4.2 Selection of Solvents and Undesirable Solvents 2488.4.3 Doping 2488.5 Conclusion and Outlook 2519 Perovskite White Light-emitting Materials and Devices 2559.1 Background ofWPeLED 2559.2 Down-conversion Method 2579.3 Full Electroluminescent PeLEDs 2619.3.1 Yellow Perovskite Light-emitting Diodes 2619.3.1.1 Zero-dimensional Sn-doped Halide Perovskites 2619.3.1.2 2D (C18H35NH3)2SnBr4 Perovskite 2639.3.1.3 Colloidal Undoped and Double-doped Cs2AgInCl6 Nanocrystals 2639.3.1.4 Introducing Separated Emitting Centers 2649.3.2 Progress in the Research of Sky-Blue Perovskite Light-emitting Diodes 2669.4 Single White Light Perovskite Materials and Self-trapped Excitons 2719.4.1 Single White Light Perovskite Materials 2719.4.1.1 (110) Perovskite with Corrugated Inorganic Layers 2719.4.1.2 (001) Perovskite with Flat Inorganic Layers 2749.4.2 Self-trapped Excitons 2749.5 Perovskite–Organic Coupling White PeLEDs 2789.6 Others 2819.7 Conclusion and Outlook 28110 Electron and Hole Transport Materials 28510.1 Background of Charge Transport Materials 28510.1.1 Charge Transport of Metal Halide Perovskite Materials 28610.1.2 Charge Transport Materials in PeLED 28810.2 Electron Transport Materials in PeLEDs 28910.2.1 Inorganic Oxides Electron Transport Materials 28910.2.2 Inorganically Doped Electron Transport Materials 29210.2.3 Organic Monolayer Electron Transport Materials 29210.2.4 Organic Multilayer Electron Transport Materials 29210.2.5 Doped Organic Electron Transport Materials 29310.2.6 Organic–Inorganic Hybrid Electron Transport Materials 29410.3 Hole Transport Materials in PeLEDs 29410.4 Progress in the Study of Hole Transport Layers and Hole Injection Layers n Perovskite Light Emitting Diodes 29510.4.1 PVK-Doped TPD, TCTA 29610.4.2 PEDOT:PSS After Methanol Treatment 29710.4.3 TB(MA) Instead of PEDOT:PSS 29910.4.4 PSS-Doped Na 30010.4.5 PVK-Doped NiOx 30010.4.6 Quantum Dot Perovskite Light Emitting Diodes: PVK-Doped PTAA 30010.4.7 PVK Blended with PBD 30110.4.8 Double HTLs with PVK and TFB 30210.4.9 Polyfluorenylbenzene Anion-Conjugated Polyelectrolytes with Counter Ions 30310.5 Conclusion and Outlook 30511 Stability of Perovskite Light-emitting Diodes 31111.1 Sources of Instability in Metal Halide Perovskites and Perovskite Light-emitting Diodes 31111.1.1 Intrinsic Instability of PeLEDs 31211.1.2 Extrinsic Instability of PeLEDs 31311.2 Analysis of the Current Stability of Perovskite Light-emitting Diodes 31411.3 Factors Affecting Efficiency Roll-off 31511.4 Strategies for Dealing with Efficiency Roll-off 31911.4.1 Perovskite Structure Modulation 31911.4.2 Hole Injection Layer Modulation 32111.4.3 Electron Injection Layer Modulation 32311.5 Conclusion and Outlook 32612 Perovskite Materials for Laser Applications 33112.1 Physics Principles of Laser 33112.2 Perovskite Laser for Different Morphologies 33512.2.1 Laser of Perovskite Films 33512.2.2 Laser of Perovskite Nanowires 33712.2.3 Laser of Perovskite Nanoplates and Microplates 33912.2.4 Laser of Perovskite Nanocrystals or Quantum Dots 34112.3 Conclusion and Outlook 342References 343Index 349