A timely and singular resource on the latest advances in organic photovoltaics
Organic photovoltaics are gaining widespread attention due to their solution processability, tunable electronic properties, low temperature manufacture, and cheap and light materials. Their wide range of potential applications may result in significant near-term commercialization of the technology.
In Organic Solar Cells: Materials Design, Technology and Commercialization, renowned scientist Dr. Liming Ding delivers a comprehensive exploration of organic solar cells, including discussions of their key materials, mechanisms, molecular designs, stability features, and applications. The book presents the most state-of-the-art developments in the field alongside fulsome treatments of the commercialization potential of various organic solar cell technologies.
The author also provides: - Thorough introductions to fullerene acceptors, polymer donors, and non-fullerene small molecule acceptors - Comprehensive explorations of p-type molecular photovoltaic materials and polymer-polymer solar cell materials, devices, and stability - Practical discussions of electron donating ladder-type heteroacenes for photovoltaic applications - In-depth examinations of chlorinated organic and single-component organic solar cells, as well as the morphological characterization and manipulation of organic solar cells
Perfect for materials scientists, organic and solid-state chemists, and solid-state physicists, Organic Solar Cells: Materials Design, Technology and Commercialization will also earn a place in the libraries of surface chemists and physicists and electrical engineers.
Table of Contents
Preface xv
1 Conjugated Polymer Donors for Organic Solar Cells 1
Xiaopeng Xu, Xiyue Yuan, Qunping Fan, Chunhui Duan, Maojie Zhang, and Qiang Peng
1.1 Introduction 1
1.2 LBG Polymers 3
1.2.1 LBG Polymers Based on Benzothiadiazole (BT) 3
1.2.2 LBG Polymers Based on Isoindigo (IID) 8
1.2.3 LBG Polymers Based on Diketopyrrolopyrrole (DPP) 14
1.3 MBG Polymers 19
1.3.1 MBG Polymers Based on Benzothiadiazole (BT) 22
1.3.2 MBG Polymers Based on Quinoxaline (Qx) 31
1.3.3 MBG Polymers Based on Thienopyrrolodione (TPD) 35
1.3.4 MBG Polymers Based on Thieno[3,4-b]thiophene (TT) 40
1.4 WBG Polymers 46
1.4.1 WBG Polymers Based on Polythiophene (PT) Derivatives 46
1.4.2 WBG Polymers Based on Benzodithiophene-alt-Thiophene Derivatives 49
1.4.3 WBG Polymers Based on Benzothiadiazole (BT) Derivatives 50
1.4.4 WBG Polymers Based on Benzotriazole (BTA) Derivatives 53
1.4.5 WBG Polymers Based on Thiazole, Pyrazine, and Their Derivatives Containing N-Heterocycles 56
1.4.6 WBG Polymers Based on Benzodithiophene-4,8-dione (BDD) Derivatives 62
1.4.7 Other WBG Polymers 65
1.5 Summary and Outlook 69
References 69
2 p-Type Molecular Photovoltaic Materials 77
Qihui Yue and Xiaozhang Zhu
2.1 Introduction 77
2.2 p-Type Molecular Photovoltaic Materials Used in Vacuum-Deposited Solar Cells 78
2.2.1 Oligothiophene-Based Molecular Donors 79
2.2.2 D-A-A′ -Type Molecular Donors 80
2.2.3 Borondipyrromethenes-Based Molecular Donors 83
2.2.4 Other Molecular Donors 85
2.3 p-Type Molecular Photovoltaic Materials Used in Solution-Processed Solar Cells 88
2.3.1 A-D-A-Type Molecular Donors 89
2.3.1.1 Oligothiophene-Based A-D-A-Type Molecular Donors 89
2.3.1.2 Benzodithiophene-Based A-D-A-Type Molecular Donors 90
2.3.1.3 Dithienosilole-Based A-D-A-Type Molecular Donors 95
2.3.1.4 Dithienopyrrole-Based A-D-A-Type Molecular Donors 96
2.3.2 D1-A-D2-A-D1-Type Molecular Donors 96
2.3.2.1 Dithienosilole-Based D1-A-D2-A-D1-Type Molecular Donors 99
2.3.2.2 Benzodithiophene-Based D1-A-D2-A-D1-Type Molecular Donors 101
2.3.2.3 Indacenodithiophene-Based D1-A-D2-A-D1-Type Molecular Donors 103
2.3.3 Porphyrin-Based Molecular Donors 105
2.3.4 Other Molecular Donors 107
2.4 Current Progress on Small-Molecule Solar Cells with Nonfullerene Acceptors 110
2.4.1 Binary Solar Cells 111
2.4.2 Ternary Solar Cells 112
2.5 Summary and Outlook 114
References 115
3 Fullerene Acceptors 121
Zuo Xiao
3.1 Introduction 121
3.2 Fullerene Acceptors for Organic Solar Cells 123
3.2.1 Pristine Fullerenes 123
3.2.2 Fullerene Monoadducts 126
3.2.2.1 [2+1] Addition Derivatives 126
3.2.2.2 [2+2] Addition Derivatives 129
3.2.2.3 [2+3] Addition Derivatives 129
3.2.2.4 [2+4] Addition Derivatives 130
3.2.2.5 1,4-Addition Derivatives 130
3.2.3 Fullerene Bisadducts 130
3.2.4 Fullerene Multiadducts 135
3.2.5 Unconventional Fullerenes 136
3.3 Summary 138
References 139
4 Non-fullerene Small-Molecule Acceptors for Organic Solar Cells 145
Wei Gao, Jun Yuan, Zhenghui Luo, Jinru Cao, Weihua Tang, Yingping Zou, and Chuluo Yang
4.1 Molecular Design Principles 145
4.2 PDI-Based SMAs 146
4.2.1 PDI Monomers 146
4.2.2 PDI Dimers 147
4.2.3 PDI Trimers 150
4.2.4 PDI Tetramers 153
4.3 A-D-A-Type SMAs 160
4.3.1 Side Chains Optimization 160
4.3.2 End Groups Engineering 164
4.3.3 Core Units Engineering 167
4.3.3.1 IDTT and Its Derivations 167
4.3.3.2 Spacer Unit Effects 176
4.3.3.3 Asymmetric Cores 184
4.3.3.4 Non-fused Cores 194
4.4 A-DA′ D-A-Type SMAs 200
4.4.1 BTA-Based A-DA′ D-A SMAs 201
4.4.2 BT-Based A-DA′ D-A SMAs 204
4.4.3 BSe- and Qx-Based OSCs 209
References 210
5 Electron-Donating Ladder-Type Heteroacenes for Photovoltaic Applications: From Polymer Donor Materials to Small-Molecule Acceptor Materials 215
Qisheng Tu, Yunlong Ma, and Qingdong Zheng
5.1 Introduction 215
5.2 D-A Copolymers Based on Ladder-Type Heteroacenes 217
5.2.1 Pentacyclic and Hexacyclic Heteroacenes-Based D-A Copolymers 217
5.2.2 Heptacene-Based D-A Copolymers 219
5.2.3 D-A Copolymers Based on Heteroacenes with Nine or More Fused Rings 222
5.3 A-D-A NFAs Based on Ladder-Type Heteroacenes 223
5.3.1 A-D-A NFAs Based on Heteropentacenes and Heterohexacenes 224
5.3.2 A-D-A NFAs Based on Heteroheptacenes 226
5.3.2.1 NFAs Based on Heteroheptacenes with sp3-Hybridized Bridging Atoms 226
5.3.2.2 NFAs Based on Heteroheptacenes Without sp3-Hybridized Bridging Atoms 231
5.3.3 A-D-A NFAs Based on Heteroacenes with Eight or More Fused Rings 233
5.3.4 Other NFAs 235
5.4 Conclusions and Outlook 236
References 237
6 Chlorinated Organic Solar Cells 241
Hui Chen, Mingrui Pu, and Feng He
6.1 Introduction 241
6.2 Chlorination Versus Fluorination: A Comprehensive Study 242
6.2.1 Synthesis 242
6.2.2 The Manipulation of Energy Level and Absorption 244
6.2.3 The Steric Hindrance and Morphology 245
6.2.4 The Synergistic Effect of Chlorination and Fluorination 246
6.3 Recent Advances in Chlorinated Semiconductors 249
6.3.1 Chlorination on the Donor Units of Polymer Donors 249
6.3.1.1 Chlorination of the Donor Units in Backbone of Polymer Donors 249
6.3.1.2 Chlorination of the Donor Units in Side Chain of Polymer Donors 250
6.3.2 Chlorination on the Acceptor Units of Polymer Donors 255
6.3.3 Chlorination of the π-Bridge of the Polymer Donors 258
6.3.4 Chlorinated Small Molecular Donors 260
6.3.5 Chlorinated Small Molecular Acceptors 260
6.3.5.1 Photovoltaic Performance of Chlorinated Small Molecular Acceptors 262
6.3.5.2 The Investigation of the Crystal Structure of Chlorinated Small Molecular Acceptors 266
6.3.5.3 The Semitransparent Organic Solar Cells Based on Chlorinated Small Molecular Acceptors 268
6.4 Conclusion and Outlook 269
References 270
7 Polymer-Polymer Solar Cells: Materials, Device, and Stability 275
Jianyu Yuan, Huiliang Sun, Yingjian Yu, Wanli Ma, Xugang Guo, and Jun Liu
7.1 Introduction 275
7.2 The Device Structure and Basic Principles of All-PSCs 277
7.3 Materials Design Toward Efficient All-PSCs 278
7.3.1 Progress of N2200 and Its Derivative-Based All-PSCs 278
7.3.1.1 Molecular Design Strategy for N2200 Derivatives 279
7.3.1.2 Molecular Design Strategy for PDI Polymers 283
7.3.1.3 Molecular Design Strategy for BTI Polymers 283
7.3.1.4 BTI Polymers for High-Performance All-PSCs with Small Eloss 287
7.3.2 Progress of Polymer Acceptors Containing B←N Unit 289
7.3.2.1 Principle of B←N Unit 289
7.3.2.2 Electron-Deficient Building Blocks Based on B←N Unit 289
7.3.2.3 Optimizing ELUMO 292
7.3.2.4 Tuning Absorption Spectra 294
7.3.2.5 Enhancing Electron Mobility 295
7.3.2.6 Optimizing Active Layer Morphology 297
7.3.3 Progress of Polymer Acceptors Bearing Cyano Groups 299
7.4 Device Performance and Stability of All-PSCs 303
7.4.1 Morphology Optimization and Device Engineering 303
7.4.2 The Enhanced Stability of All-PSCs 307
7.4.2.1 Thermal Stability 307
7.4.2.2 Ambient Stability 308
7.4.2.3 Mechanical Stability 308
7.4.2.4 Photostability 309
7.5 Conclusion and Outlook 310
References 310
8 Organic Solar Cells with High Open-Circuit Voltage >1 V 313
Ailing Tang, Yuze Lin, and Erjun Zhou
8.1 Introduction 313
8.2 n-Type Small-Molecule Acceptors 315
8.2.1 Fullerene-Based SMAs 315
8.2.2 Non-fullerene SMAs 317
8.2.2.1 PDI-Based SMAs 317
8.2.2.2 IC and Its Derivatives-Based A-D-A-Type SMAs 319
8.2.2.3 A2-A1-D-A1-A2-Type SMAs with BT as A1 Units 322
8.2.2.4 A2-A1-D-A1-A2-Type SMAs with BTA or Qx as A1 Units 325
8.3 n-Type Polymers 328
8.4 Conclusion and Outlook 330
References 331
9 Single-Component Organic Solar Cells 335
Guitao Feng, Yiting Guo, and Weiwei Li
9.1 Introduction 335
9.2 Single-Component Conjugated Materials for SCOSCs 336
9.2.1 Molecular Dyads 336
9.2.1.1 Fullerene-Based “In-Chain” Molecular Dyads 336
9.2.1.2 Fullerene-Based “Side-Chain” D-A Molecular Dyads 339
9.2.1.3 PBI-Based Molecular Dyads 341
9.2.2 Block Copolymers 345
9.2.3 Double-Cable Conjugated Polymers 350
9.3 Morphological Studies of the Photo-Active Layers in the SCOSCs 361
9.3.1 Morphological Studies of the Molecular Dyads in SCOSCs 362
9.3.2 Morphological Studies of the Block Copolymers in SCOSCs 366
9.3.3 Morphological Studies of the Double-Cable Polymers in SCOSCs 367
9.4 Perspective and Challenges of SCOSCs 375
References 377
10 Tandem Organic Solar Cells: Recent Progress and Challenge 381
Lingxian Meng, Xiangjian Wan, and Yongsheng Chen
10.1 Introduction 381
10.2 Active Layer Materials in Tandem OSCs 383
10.2.1 Tandem OSCs Based on Fullerene Acceptors 384
10.2.2 Tandem OSCs Based on Non-fullerene Acceptors 393
10.3 Interconnecting Layer Materials 397
10.4 The Semi-Empirical Analysis of Tandem OSCs 398
10.5 Conclusion and Outlook 400
Acknowledgments 401
References 401
11 Large-Area Flexible Organic Solar Cells 405
Shaorong Huang, Yufei Wang, Lintao Hou, and Lie Chen
11.1 Introduction 405
11.2 Material Requirements for Large-Area Flexible Organic Solar Cells 406
11.2.1 Fullerene-Based Binary System 406
11.2.2 Non-fullerene-Based Binary System 410
11.2.3 Ternary System 413
11.2.4 All-Polymer-Based System 415
11.2.5 Design Strategies of the Materials for Large-Area Devices 417
11.3 Flexible Electrodes and Substrates 417
11.3.1 Flexible Substrates 418
11.3.2 Flexible Transparent Electrode Designs 419
11.3.2.1 Conducting Polymers 419
11.3.2.2 Carbon Nanotubes 423
11.3.2.3 Graphene 426
11.3.2.4 Metallic Nanowires 429
11.3.2.5 Hybrid Films 432
11.4 Large-Area Flexible Device Fabrication 434
11.4.1 Coating and Printing Methods 435
11.4.1.1 Blade Coating 436
11.4.1.2 Slot-Die Coating 438
11.4.1.3 Inkjet Printing 440
11.4.1.4 Spray Coating 441
11.4.1.5 Screen Printing, Relief Printing, and Gravure Printing 442
11.4.2 R2R Methodology 443
11.5 Efficiency Loss in Large-Area Devices and Modules 445
11.5.1 Electrical Loss 446
11.5.2 Geometric Loss 447
11.5.3 Optical Loss 448
11.5.4 Additional Loss 448
11.5.5 Modular Designs 448
11.6 Conclusion and Outlook 449
References 449
12 Organic Photovoltaics for Indoor Applications 455
Zhan′ ao Tan, Yinglong Bai, and Shan Jiang
12.1 Introduction 455
12.2 The Characteristics of Indoor Lighting Sources 458
12.3 Testing System and Parameters for Indoor OPVs 460
12.4 Research Progresses 461
12.4.1 Fullerene-Based OPVs for Indoor Application 462
12.4.2 Non-fullerene-Based OPVs for Indoor Application 472
12.4.3 Multiple Blend OPVs for Indoor Application 474
12.4.4 Interface Engineering of OPVs for Indoor Application 476
12.4.5 Thick Film OPVs for Indoor Application 479
12.4.6 Large-Area OPVs for Indoor Application 480
12.5 Summary and Prospective 483
References 484
13 Interfacial Design for Efficient Organic Solar Cells 487
Yao Liu, Menglan Lv, and Shengjian Liu
13.1 Introduction 487
13.2 The Mechanism and Effect of Interfacial Design 488
13.2.1 The Role of Electrode Work-Function Difference 488
13.2.2 The Interaction Between Metal Electrode and Interlayers 490
13.2.3 Doping Effect on Energy Level Alignment 492
13.2.4 Interface on BHJ Morphology and Device Stability 494
13.2.5 Interfacial Morphology Characterizations 495
13.3 Anode Interlayer Materials 496
13.3.1 PEDOT:PSS 496
13.3.2 Conjugated Polyelectrolytes 501
13.3.3 Cross-Linkable Polymers 502
13.3.4 Graphene Oxides (GOs) 504
13.3.5 Metal Oxides (MOs) 505
13.4 Cathode Interlayer Materials 506
13.4.1 Organic Small Molecules 506
13.4.2 Polymer Cathode Interlayer Materials 510
13.4.3 Graphene Derivatives and Other Emerging Alternatives 512
13.5 Conclusion and Outlook 513
References 514
14 Morphological Characterization and Manipulation of Organic Solar Cells 519
Wei Li, Long Ye, and Tao Wang
14.1 Introduction 519
14.2 Morphological Characterization of Organic Solar Cells 521
14.2.1 Microscopic Methods 521
14.2.2 Scattering Methods 526
14.2.3 Depth Profile 534
14.3 Morphological Manipulation of Organic Solar Cells 538
14.3.1 Thermal Annealing 538
14.3.2 Solvent Vapor Annealing 540
14.3.3 Solvent 542
14.3.4 Solvent Additive 544
14.3.5 Solid Additive 547
14.3.6 Substrate Effect 549
14.4 Conclusion 551
References 552
15 Operational Stability and Built-in Potential in Organic Solar Cells 555
Weixia Lan, Bo Wu, and Furong Zhu
15.1 Introduction 555
15.2 Bimolecular Recombination in Organic Solar Cells 557
15.2.1 Effect of Metal Oxide Interlayer on Cell Performance 557
15.2.2 Charge Recombination Processes in Organic Solar Cells 560
15.2.3 Bias-Dependent Charge Collection 564
15.3 Metal/Organic Interfacial Exciton Dissociation in Organic Solar Cells 565
15.3.1 Charge Collection in Regular Configuration Organic Solar Cells 566
15.3.2 Charge Collection in Inverted Organic Solar Cells 569
15.4 Improvement of Charge Collection and Performance Reproducibility 571
15.4.1 Effect of Metal Oxide Interlayer on Cell Performance 571
15.4.2 Suppression of ZnO Sub-Gap States 574
15.5 Effect of Built-in Potential on Stability of Organic Solar Cells 579
15.5.1 Interlayer Modification 580
15.5.2 Built-in Potential in Organic Solar Cells 582
15.5.3 Stability of Organic Solar Cells 584
15.6 Summary 587
Acknowledgment 587
References 587
16 Voltage Losses and Charge Transfer States in Donor-Acceptor Organic Solar Cells 591
Hongbo Wu, Mengyang Li, Zaifei Ma, and Zheng Tang
16.1 The Origin of Voc of Solar Cells 591
16.1.1 Voltage Loss in an Ideal Solar Cell and the Upper Limit for Voc 591
16.1.2 Voc and Voltage Loss in Non-ideal Solar Cells 594
16.2 Voc of Organic Solar Cells 596
16.2.1 Charge Transfer States in Organic Solar Cells 596
16.2.2 Relation Between CT State and Voc of Organic Solar Cells 597
16.2.3 Determining Factors of Kr and Knr for Organic Solar Cells 601
16.2.4 Experimental Determination of CT State-Related Parameters 604
16.3 Strategies to Reduce Vnr and Vr in Organic Solar Cells 606
16.4 Summary 609
Acknowledgments 610
References 610
17 Stability of Organic Solar Cells: From Fullerene Derivatives to Non-fullerene Acceptors 613
Xiaoyan Du, Jing Guo, Jie Min, and Ning Li
17.1 Introduction 613
17.2 Factors Limiting the Stability of Organic Solar Cells 614
17.2.1 Extrinsic Stresses 614
17.2.1.1 Light Effect 614
17.2.1.2 Thermal Effect 615
17.2.1.3 Environmental Effect 615
17.2.1.4 Mechanical Stress Effect 615
17.2.2 Intrinsic Factors 616
17.3 Stability Evaluation Protocols 617
17.4 Progress in Developing Stable Organic Solar Cells 618
17.4.1 Development of Organic Photovoltaic Materials with Stable Microstructure Morphology 618
17.4.1.1 Organic Solar Cells Based on Fullerene Acceptors 621
17.4.1.2 Organic Solar Cells Based on Non-fullerene Acceptors 623
17.4.1.3 Organic Solar Cells Based on Polymeric Acceptors 625
17.4.2 Strategies to Enhance the Morphological Stability of Organic Solar Cells 625
17.4.2.1 Introducing Hydrogen Bonding in the Photo-Active Materials 627
17.4.2.2 Chemically Linked Donor and Acceptor as a Single-Component Photoactive Layer 627
17.4.2.3 Cross-Linking 629
17.4.2.4 Solid Additives 631
17.4.2.5 Solvent Additives 631
17.4.2.6 Ternary and Multiple Composites 633
17.4.2.7 Organic Nanoparticles 633
17.4.2.8 Stratified Photoactive Layer Structure 633
17.5 Recent Progress on Developing Organic Solar Cells with Excellent Stability 635
17.6 Summary and Outlook 639
References 640
18 Potential Applications of Organic Solar Cells 645
Chengyi Xiao and Weiwei Li
18.1 Introduction 645
18.2 Building-Integrated OSCs 647
18.2.1 Solar Parks 648
18.2.2 Smart Windows 650
18.2.3 Solar Trees 651
18.2.4 Greenhouse and Photosynthesis 652
18.3 Wearable-Integrated OSCs 655
18.3.1 Portable Device Photovoltaics 655
18.3.2 Implantable and Wearable Self-Powered Sensors 656
18.3.3 OSC Textile Toward Smart Clothing 658
18.4 OSCs-Integrated Energy Storage System 661
18.4.1 Planar Stacked OSCs-Integrated ESS 662
18.4.2 Fiber-Based OSCs-Integrated ESS 665
18.5 Other Applications 666
18.5.1 OSCs-Driven Water Splitting 666
18.5.2 OSCs-Integrated Glasses 668
18.6 Conclusion and Outlook 668
References 672
Index 677
