Hybrid Perovskite Solar Cells

Visible/UV Region 96 4.2.2 IR Region 98 4.2.3 THz Region 99 4.3 Band Gap of Hybrid Perovskites 101 4.3.1 Band Gap Analysis of MAPbI3 101 4.3.2 Band Gap of Basic Perovskites 103 4.3.3 Band Gap Variation in Perovskite Alloys 105 4.4 True Absorption Coefficient of MAPbI3 106 4.4.1 Principles of Optical Measurements 107 4.4.2 Interpretation of a Variation 108 4.5 Universal Rules for Hybrid Perovskite Optical Properties 111 4.5.1 Variation with Center Cation 111 4.5.2 Variation with Halide Anion 112 4.6 Subgap Absorption Characteristics 114 4.7 Temperature Effect on Absorption Properties 116 4.8 Excitonic Properties of Hybrid Perovskites 117 References 119 5 Physical Properties Determined by Density Functional Theory 123 Hiroyuki Fujiwara, Mitsutoshi Nishiwaki, and Yukinori Nishigaki 5.1 Introduction 123 5.2 What Is DFT? 124 5.2.1 Basic Principles 124 5.2.2 Assumptions and Limitations 126 5.3 Crystal Structures Determined by DFT 128 5.3.1 Hybrid Perovskite Structures 128 5.3.2 Organic-Center Cations 131 5.4 Band Structures 132 5.4.1 Band Structures of Hybrid Perovskites 132 5.4.2 Direct-Indirect Issue of Hybrid Perovskite 134 5.4.3 Density of States 139 5.4.4 Effective Mass 140 5.5 Band Gap 141 5.5.1 What Determines Band Gap? 142 5.5.2 Effect of Center Cation 143 5.5.3 Effect of Halide Anion 143 5.6 Defect Physics 144 Acknowledgment 147 References 147 6 Carrier Transport Properties 151 Hiroyuki Fujiwara and Yoshitsune Kato 6.1 Introduction 151 6.2 Carrier Properties of Hybrid Perovskites 153 6.2.1 Self-Doping in Hybrid Perovskites 153 6.2.2 Effect of Carrier Concentration on Mobility 155 6.3 Carrier Mobility of MAPbI3 155 6.3.1 Variation of Mobility with Characterization Method 156 6.3.2 Temperature Dependence 159 6.3.3 Effect of Effective Mass 160 6.3.4 What Determines Maximum Mobility of MAPbI3? 161 6.4 Diffusion Length 164 6.5 Carrier Transport in Various Hybrid Perovskites 166 References 168 7 Ferroelectric Properties 173 Tobias Leonhard, Holger Röhm, Alexander D. Schulz, and Alexander Colsmann 7.1 On the Importance of Ferroelectricity in Hybrid Perovskite Solar Cells 173 7.2 Ferroelectricity 174 7.2.1 Crystallographic Considerations 174 7.2.2 Ferroelectricity in Thin Films 178 7.2.3 Crystallography of MAPbI3 Thin Films 178 7.3 Probing Ferroelectricity on the Microscale 179 7.3.1 Atomic Force Microscopy 179 7.3.2 Piezoresponse Force Microscopy 180 7.3.3 Characterization of MAPbI3 Thin Films with sf-PFM 183 7.3.4 Correlative Domain Characterization 188 7.3.4.1 Transmission Electron Microscopy 188 7.3.4.2 X-ray Diffraction 189 7.3.4.3 Electron Backscatter Diffraction 189 7.3.4.4 Kelvin Probe Force Microscopy 191 7.3.5 Polarization Orientation 191 7.3.6 Ferroelastic Effects in MAPbI3 Thin Films 193 7.4 Ferroelectric Poling of MAPbI3 195 7.4.1 AC Poling of MAPbI3 196 7.4.2 Creeping Poling and Switching Events on the Microscopic Scale 197 7.4.3 Macroscopic Effects of Poling 200 7.5 Impact of Ferroelectricity on the Performance of Solar Cells 201 7.5.1 Pitfalls During Sample Measurements 201 7.5.2 Charge Carrier Dynamics in Solar Cells 203 References 203 8 Photoluminescence Properties 207 Yasuhiro Yamada and Yoshihiko Kanemitsu 8.1 Introduction 207 8.2 Overview of Luminescent Properties 208 8.3 Room-Temperature PL Spectra of a Hybrid Perovskite Thin Film 209 8.4 Time-Resolved PL of a Hybrid Perovskite 213 8.5 PL Quantum Efficiency 218 8.6 Temperature-Dependent PL 220 8.7 Material and Device Characterization by PL Spectroscopy 222 8.7.1 Degradation and Healing of Hybrid Perovskites 222 8.7.2 Charge Transfer Mechanism in Perovskite Solar Cell 223 8.8 Conclusion 224 Acknowledgment 225 References 225 9 Role of Grain Boundaries 229 Jae Sung Yun 9.1 Introduction 229 9.2 Role of Grain Boundaries in Device Performance 230 9.2.1 Potential Barrier at GBs and Charge Transport 231 9.2.2 Engineering of GB Properties 234 9.3 Ion Migration Through Grain Boundaries 241 9.3.1 Enhanced Ion Transport at Grain Boundaries 241 References 250 10 Roles of Center Cations 253 Biwas Subedi, Juan Zuo, Marie Solange Tumusange, Maxwell M. Junda, Kiran 10.1 Ghimire, and Nikolas J. Podraza Introduction 253 10.2 Cubic Perovskite Phase Tolerance Factor 256 10.3 Thin Film Stability 258 10.4 Optoelectronic Property Variations 263 10.5 Solar Cell Performance 268 References 271 Part II Hybrid Perovskite Solar Cells 275 11 Operational Principles of Hybrid Perovskite Solar Cells 277 Hiroyuki Fujiwara, Yoshitsune Kato, Yuji Kadoya, Yukinori Nishigaki, Tomoya Kobayashi, Akio Matsushita, and Taisuke Matsui 11.1 Introduction 277 11.2 Operation of Hybrid Perovskite Solar Cells 278 11.2.1 Operational Principle and Basic Structures 278 11.2.2 Band Alignment 281 11.3 Band Diagram of Hybrid Perovskite Solar Cells 283 11.3.1 Device Simulation 283 11.3.2 Experimental Observation 285 11.4 Refined Analyses of Hybrid Perovskite Solar Cells 287 11.4.1 Carrier Generation and Loss 287 11.4.2 Power Loss Mechanism 291 11.4.3 e-ARC Software 295 11.5 What Determines V oc? 295 11.5.1 Effect of Interface 297 11.5.2 Effect of Passivation 300 11.5.3 Effect of Grain Boundary 303 References 305 12 Efficiency Limits of Single and Tandem Solar Cells 309 Hiroyuki Fujiwara, Yoshitsune Kato, Masayuki Kozawa, Akira Terakawa, and Taisuke Matsui 12.1 Introduction 309 12.2 What Is the SQ Limit? 310 12.2.1 Physical Model 311 12.2.2 Blackbody Radiation 313 12.2.3 SQ Limit 315 12.3 Maximum Efficiencies of Perovskite Single Cells 319 12.3.1 Concept of Thin-Film Limit 319 12.3.2 EQE Calculation Method 321 12.3.3 Maximum Efficiencies of Single Solar Cells 323 12.3.4 Performance-Limiting Factors of Hybrid Perovskite Devices 325 12.4 Maximum Efficiency of Tandem Cells 327 12.4.1 Optical Model and Assumptions 328 12.4.2 Calculation of Tandem-Cell EQE Spectra 329 12.4.3 Maximum Efficiencies of Tandem Devices 331 12.4.4 Realistic Maximum Efficiency of Tandem Cell 334 12.5 Free Software for Efficiency Limit Calculation 335 References 336 13 Multi-cation Hybrid Perovskite Solar Cells 339 Jacob N. Vagott and Juan-Pablo Correa-Baena 13.1 Introduction 339 13.2 Types of A-Site Multi-cation Hybrid Perovskite Solar Cells 341 13.2.1 Pb-Based Multi-cation Hybrid Perovskite Solar Cells 341 13.2.2 Sn-Based Multi-cation Hybrid Perovskite Solar Cells 344 13.3 Cation Selection in Mixed-Cation Hybrid Perovskite Solar Cells 345 13.3.1 Organic A-Cations 345 13.3.2 Inorganic A-Cations 347 13.4 Fabrication of Mixed-Cation Hybrid Perovskite Solar Cells 349 13.4.1 Traditional Fabrication Approach 349 13.4.2 Emerging Fabrication Technologies 350 13.5 Charge Transport Materials 353 13.6 Surface Passivation 357 13.7 Mixed B-Cation Hybrid Organic?Inorganic Perovskite Solar Cells 361 13.8 Basic Characterization of Mixed-Cation Hybrid Perovskite Solar Cells 362 References 365 14 Tin Halide Perovskite Solar Cells 373 Gaurav Kapil and Shuzi Hayase 14.1 Introduction 373 14.1.1 Device Structure and Operating Principle 374 14.1.2 Crystal Structure 375 14.2 Tin Perovskite Solar Cells 376 14.2.1 Intrinsic Properties 377 14.2.2 Carrier Lifetime and Diffusion Length 378 14.3 The Status of Sn Perovskite Solar Cells 379 14.3.1 Different Type of Sn Perovskite Solar Cells 380 14.3.1.1 CsSnI3 380 14.3.1.2 MASnI3 383 14.3.1.3 FASnI3 384 14.3.1.4 FAxMA1-xSnI3 385 14.3.1.5 2D/3D FASnI3 387 14.3.1.6 Sn-Ge mixed PSCs 387 14.3.2 Strategies to Improve the Efficiency 389 14.3.2.1 Film Fabrication Methods 389 14.3.2.2 Use of Reducing Agents 389 14.3.2.3 Doping Effect of Large Organic Cations 390 14.3.2.4 Device Engineering and Lattice Relaxation 391 14.4 Sn-Pb Perovskite Solar Cells 393 14.4.1 Anomalous Bandgap of SnPb (The Bowing Effect) 396 14.4.2 Physical Properties 398 14.4.2.1 Intrinsic Carrier Concentration 398 14.4.2.2 Carrier Lifetime and Diffusion Length 399 14.5 The Status of Sn-Pb Perovskite Solar Cells 399 14.5.1 Different Types of Sn-Pb Perovskite Solar Cells 401 14.5.1.1 First Kind of Sn-Pb PSC absorber: MASnxPb1-xI3 401 14.5.1.2 Multi Cation Sn-Pb Perovskites: (FA, MA, Cs) (Sn, Pb) (I, Br, Cl)3 401 14.5.2 Strategies to Improve the Efficiency 403 14.5.2.1 Use of Additives 403 14.5.2.2 Device Engineering 404 14.6 Conclusion and Outlook 406 References 406 15 Stability of Hybrid Perovskite Solar Cells 411 Seigo Ito 15.1 Introduction: Trigger of the Degradation 411 15.2 Crystal Quality for Stable Perovskite Solar Cells 413 15.3 Water-Stable and MA-Free Perovskites 415 15.4 Defects and Grain-Surface Ion Migration, and Passivation (Including 2-D Crystal) 417 15.5 Degradation at Interface with Metal Oxides 420 15.6 Porous Carbon Electrode to Be Very Stable Multiporous-Layered- Electrode Perovskite Solar Cells (MPLE-PSC) 420 15.7 Damp Heat Tests 421 15.8 Conclusion 422 References 425 16 Hysteresis in J-V Characteristics 429 Wolfgang Tress 16.1 Introduction and Definitions: What Do We Mean by Hysteresis? 429 16.2 The JV Curve of a Solar Cell: What Does It Tell? 431 16.3 Characteristics of Hysteresis: What Does It Depend on? 437 16.4 Mechanistic and Microscopic Origin of Hysteresis: What Changes Slowly? 442 16.5 Issues with Hysteresis: How to Tune/Avoid/Suppress? 453 16.6 Conclusion and Open Questions 453 References 454 17 Perovskite-Based Tandem Solar Cells 463 Klaus Jäger and Steve Albrecht 17.1 Introduction 463 17.2 Architectures of Tandem Solar Cells 465 17.2.1 Monolithic Two-Terminal Solar Cells 466 17.2.2 Four-Terminal Tandem Solar Cells 467 17.2.3 Other Concepts 468 17.2.4 Bifacial Solar Cells 469 17.3 Efficiency Limits of Multi-Junction Solar Cells 469 17.3.1 Efficiency Limit for Four-Terminal Tandem Solar Cells 470 17.3.2 Efficiency Limit for Two-Terminal Tandem Solar Cells 472 17.3.3 Efficiency Limit for Cells with More Junctions 474 17.4 Perovskites as Tandem Solar Cell Materials 474 17.5 Experimental Results on Perovskite-Based Tandem Solar Cells 477 17.5.1 Perovskite/Silicon Tandem Solar Cells 482 17.5.2 Perovskite-Chalcogenide Tandem Solar Cells 489 17.6 Energy Yield Calculations 493 17.6.1 Illumination Model 494 17.6.2 Optical Model 494 17.6.3 Electrical Model 496 17.6.4 Temperature Model 498 17.6.5 Energy Yield Calculation 498 17.7 Conclusions and Outlook 499 Acknowledgments 500 References 500 18 All Perovskite Tandem Solar Cells 509 Zhaoning Song and Yanfa Yan 18.1 Introduction 509 18.2 Working Principles of Tandem Solar Cells 511 18.2.1 Why to Use Tandem Solar Cells 511 18.2.2 Tandem Device Architectures 513 18.2.3 PCE of Tandem Solar Cells 514 18.3 Wide-Bandgap Perovskite Solar Cells 516 18.3.1 Wide-Bandgap Mixed I-Br Perovskites 516 18.3.2 Current State of Wide-Bandgap Perovskite Solar Cells 518 18.3.3 Critical Issues of Wide-Bandgap Perovskite Cells 519 18.4 Low-Bandgap Perovskite Solar Cells 520 18.4.1 Low-Bandgap Mixed Sn-Pb Perovskites 520 18.4.2 Current State of Low-Bandgap Perovskite Solar Cells 524 18.4.3 Critical Issues of Low-Bandgap Perovskite Cells 525 18.5 All-Perovskite Tandem Solar Cells 527 18.5.1 4-T All-Perovskite Tandem Solar Cells 527 18.5.2 2-T All-Perovskite Tandem Solar Cells 528 18.5.3 Limitations and Challenges of All-Perovskite Tandem Solar Cells 533 18.6 Conclusion and Outlooks 534 Acknowledgments 535 References 535 A Optical Constants of Hybrid Perovskite Materials 541 Yukinori Nishigaki, Akio Matsushita, Alvaro Tejada, Taisuke Matsui, and Hiroyuki Fujiwara References 562 B Numerical Values of Shockley-Queisser Limit 563 Yoshitsune Kato and Hiroyuki Fujiwara Index 567