Rational Design of Solar Cells for Efficient Solar Energy Conversion

Alagarsamy Pandikumar, Ph.D., is a Scientist at the Functional Materials Division, CSIR-Central Electrochemical Research Institute, and leads the Solar Energy Materials Research Group. Ramasamy Ramaraj, Ph.D., is a CSIR-Emeritus Scientist in the School of Chemistry, at Madurai Kamaraj University, where he continues his research work on photoelectrochemistry.

• Biographies xiiiList of Contributors xvPreface xix1 Metal Nanoparticle Decorated ZnO Nanostructure Based Dye‐Sensitized Solar Cells 1Gregory Thien Soon How, Kandasamy Jothivenkatachalam, Alagarsamy Pandikumar, and Nay Ming Huang1.1 Introduction 11.2 Metal Dressed ZnO Nanostructures as Photoanodes 31.2.1 Metal Dressed ZnO Nanoparticles as Photoanodes 41.2.2 Metal Dressed ZnO Nanorods as Photoanodes 61.2.3 Metal Dressed ZnO Nanoflowers as Photoanodes 81.2.4 Metal Dressed ZnO Nanowires as Photoanodes 81.2.5 Less Common Metal Dressed ZnO Nanostructures as Photoanodes 101.2.6 Comparison of the Performance of Metal Dressed ZnO Nanostructures in DSSCs 101.3 Conclusions and Outlook 11References 132 Cosensitization Strategies for Dye‐Sensitized Solar Cells 15Gachumale Saritha, Sambandam Anandan, and Muthupandian Ashokkumar2.1 Introduction 152.2 Cosensitization 182.2.1 Cosensitization of Metal Complexes with Organic Dyes 192.2.1.1 Phthalocyanine‐based Metal Complexes 192.2.1.2 Porphyrin‐based Metal Complexes 212.2.1.3 Ruthenium‐based Metal Complexes 272.2.2 Cosensitization of Organic–Organic Dyes 412.3 Conclusions 51Acknowledgements 51References 523 Natural Dye‐Sensitized Solar Cells – Strategies and Measures 61N. Prabavathy, R. Balasundaraprabhu, and Dhayalan Velauthapillai3.1 Introduction 613.1.1 Mechanism of the Dye‐Sensitized Solar Cell Compared with the Z‐scheme of Photosynthesis 623.2 Components of Dye‐sensitized Solar Cell 633.2.1 Photoelectrode 633.2.2 Dye 643.2.3 Liquid Electrolyte 643.2.4 Counterelectrode 653.3 Fabrication of Natural DSSCs 653.3.1 Preparation of TiO2 Nanorods by the Hydrothermal Method 653.3.2 Characterization of the Photoelectrode for DSSCs 663.3.3 Preparation of Natural Dye 673.3.4 Sensitization 683.3.5 Arrangement of the DSSC 683.4 Efficiency and Stability Enhancement in Natural Dye‐Sensitized Solar Cells 683.4.1 Effect of Photocatalytic Activity of TiO2 Molecules on the Photostability of Natural Dyes 693.4.1.1 Important Points to be Considered for the Preparation of Photoelectrodes 703.4.2 Citric Acid – Best Solvent for Extracting Anthocyanins 703.4.3. Algal Buffer Layer to Improve Stability of Anthocyanins in DSSCs 723.4.3.1 Preparation of Buffer Layers – Sodium Alginate and Spirulina 733.4.4 Sodium‐doped Nanorods for Enhancing the Natural DSSC Performance 753.4.4.1 Preparing Sodium‐doped Nanorods as the Photoelectrode 753.4.5 Absorber Material for Liquid Electrolytes to Avoid Leakage 773.5 Other Strategies and Measures taken in DSSCs Using Natural Dyes 793.6 Conclusions 82References 824 Advantages of Polymer Electrolytes for Dye‐Sensitized Solar Cells 85L.P. Teo and A.K. Arof4.1 Why Solar Cells? 854.2 Structure and Working Principle of DSSCs with Gel Polymer Electrolytes (GPEs) 864.3 Gel Polymer Electrolytes (GPEs) 874.3.1 Chitosan (Ch) and Blends 884.3.2 Phthaloylchitosan (PhCh) and Blends 914.3.3 Poly(Vinyl Alcohol) (PVA) 984.3.4 Polyacrylonitrile (PAN) 1054.3.5 Polyvinylidene Fluoride (PVdF) 1094.4 Summary and Outlook 110Acknowledgements 111References 1115 Advantages of Polymer Electrolytes Towards Dye‐sensitized Solar Cells 121Nagaraj Pavithra, Giovanni Landi, Andrea Sorrentino, and Sambandam Anandan5.1 Introduction 1215.1.1 Energy Demand 1215.1.1.1 Generation of Solar Cells 1225.1.2 Types of Electrolyte Used in Third Generation Solar Cells 1245.1.2.1 Liquid Electrolytes (LEs) 1245.1.2.2 Room Temperature Ionic Liquids (RTILs) 1255.1.2.3 Solid State Hole Transport Materials (SS‐HTMs) 1265.2 Polymer Electrolytes 1275.2.1 Mechanism of Ion Transport in Polymer Electrolytes 1285.2.2 Types of Polymer Electrolyte 1295.2.2.1 Solid Polymer Electrolytes 1295.2.2.2 Gel Polymer Electrolytes 1295.2.2.3 Composite Polymer Electrolyte 1305.3 Dye‐ sensitized Solar Cells 1305.3.1 Components and Operational Principle 1315.3.1.1 Substrate 1335.3.1.2 Photoelectrode 1345.3.1.3 Photosensitizer 1355.3.1.4 Redox Electrolyte 1375.3.1.5 Counter Electrode 1405.3.2 Application of Polymer Electrolytes in DSSCs 1405.3.2.1 Solid‐state Dye-Sensitized Solar Cells (SS‐DSSCs) 1405.3.2.2 Quasi‐solid‐state Dye-Sensitized Solar Cells (QS‐DSSC) 1425.3.2.3 Types of Additives in GPEs 1445.3.3 Bifacial DSSCs 1485.4 Quantum Dot Sensitized Solar Cells (QDSSC) 1505.5 Perovskite‐ Sensitized Solar Cells (PSSC) 1525.6 Conclusion 153Acknowledgements 154References 1546 Rational Screening Strategies for Counter Electrode Nanocomposite Materials for Efficient Solar Energy Conversion 169Prabhakarn Arunachalam6.1 Introduction 1696.2 Principles of Next Generation Solar Cells 1716.2.1 Dye‐sensitized Solar Cells 1716.2.2 Principles of Quantum Dot Sensitized Solar Cells 1736.2.3 Principles of Perovskite Solar Cells 1746.3 Platinum‐ free Counterelectrode Materials 1756.3.1 Carbon‐based Materials for Solar Energy Conversion 1756.3.2 Metal Nitride and Carbide Materials 1786.3.3 Metal Sulfide Materials 1796.3.4 Composite Materials 1826.3.5 Metal Oxide Materials 1836.3.6 Polymer Counterelectrodes 1846.4 Summary and Outlook 185References 1867 Design and Fabrication of Carbon‐based Nanostructured Counter Electrode Materials for Dye‐sensitized Solar Cells 193Jayaraman Theerthagiri, Raja Arumugam Senthil, and Jagannathan Madhavan7.1 Photovoltaic Solar Cells – An Overview 1937.1.1 First Generation Solar Cells 1947.1.2 Second Generation Solar Cells 1947.1.3 Third Generation Solar Cells 1947.1.4 Fourth Generation Solar Cells 1957.2 Dye‐ sensitized Solar Cells 1957.2.1 Major Components of DSSCs 1967.2.1.1 Transparent Conducting Glass Substrate 1977.2.1.2 Photoelectrode 1977.2.1.3 Dye Sensitizer 1987.2.1.4 Redox Electrolytes 1997.2.1.5 Counterelectrode 2007.2.2 Working Mechanism of DSSCs 2007.3 Carbon‐ based Nanostructured CE Materials for DSSCs 2017.4 Conclusions 216References 2178 Highly Stable Inverted Organic Solar Cells Based on Novel Interfacial Layers 221Fang Jeng Lim and Ananthanarayanan Krishnamoorthy8.1 Introduction 2218.2 Research Areas in Organic Solar Cells 2228.3 An Overview of Inverted Organic Solar Cells 2248.3.1 Transport Layers in Inverted Organic Solar Cells 2278.3.2 PEDOT:PSS Hole Transport Layer 2278.3.3 Titanium Oxide Electron Transport Layer 2298.4 Issues in Inverted Organic Solar Cells and Respective Solutions 2328.4.1 Wettability Issue of PEDOT:PSS in Inverted Organic Solar Cells 2338.4.2 Light‐soaking Issue of TiOx‐based Inverted Organic Solar Cells 2348.5 Overcoming the Wettability Issue and Light‐soaking Issue in Inverted Organic Solar Cells 2358.5.1 Fluorosurfactant‐modified PEDOT:PSS as Hole Transport Layer 2358.5.2 Fluorinated Titanium Oxide as Electron Transport Layer 2398.6 Conclusions and Outlook 245Acknowledgements 246References 2469 Fabrication of Metal Top Electrode via Solution‐based Printing Technique for Efficient Inverted Organic Solar Cells 255Navaneethan Duraisamy, Kavitha Kandiah, Kyung‐Hyun Choi, Dhanaraj Gopi, Ramesh Rajendran, Pazhanivel Thangavelu, and Maadeswaran Palanisamy9.1 Introduction 2559.2 Organic Photovoltaic Cells 2579.3 Working Principle 2589.4 Device Architecture 2609.4.1 Single Layer or Monolayer Device 2609.4.2 Planar Heterojunction Device 2619.4.3 Bulk Heterojunction Device 2619.4.4 Ordered Bulk Heterojunction Device 2619.4.5 Inverted Organic Solar Cells 2629.5 Fabrication Process 2639.5.1 Hybrid‐EHDA Technique 2639.5.1.1 Flow Rate 2659.5.1.2 Applied Potential 2659.5.1.3 Pneumatic Pressure 2659.5.1.4 Stand‐off Distance 2659.5.1.5 Nozzle Diameter 2669.5.1.6 Ink Properties 2669.5.2 Mode of Atomization 2679.5.2.1 Dripping Mode 2679.5.2.2 Unstable Spray Mode 2679.5.2.3 Stable Spray Mode 2679.6 Fabrication of Inverted Organic Solar Cells 2679.6.1 Deposition of Zinc Oxide (ZnO) on ITO Substrate 2689.6.2 Deposition of P3HT:PCBM 2689.6.3 Deposition of PEDOT:PSS 2689.6.4 Deposition of Silver as a Top Electrode 2699.7 Device Morphology 2729.8 Device Performance 2739.9 Conclusion 277Acknowledgements 277References 27710 Polymer Solar Cells – An Energy Technology for the Future 283Alagar Ramar and Fu‐Ming Wang10.1 Introduction 28310.2 Materials Developments for Bulk Heterojunction Solar Cells 28410.2.1 Conjugated Polymer–Fullerene Solar Cells 28410.2.2 Non‐Fullerene Polymer Solar Cells 28910.2.3 All‐Polymer Solar Cells 29010.3 Materials Developments for Molecular Heterojunction Solar Cells 29110.3.1 Double‐cable Polymers 29110.4 Developments in Device Structures 29310.4.1 Tandem Solar Cells 29510.4.2 Inverted Polymer Solar Cells 29710.5 Conclusions 300Acknowledgements 300References 30111 Rational Strategies for Large‐area Perovskite Solar Cells: Laboratory Scale to Industrial Technology 307Arunachalam Arulraj and Mohan Ramesh11.1 Introduction 30711.2 Perovskite 30811.3 Perovskite Solar Cells 30911.3.1 Architecture 31011.3.1.1 Mesoporous PSCs 31011.3.1.2 Planar PSCs 31311.4 Device Processing 31311.4.1 Solvent Engineering 31311.4.2 Compositional Engineering 31411.4.3 Interfacial Engineering 31411.5 Enhancing the Stability of Devices 31611.5.1 Deposition Techniques 31711.5.1.1 Spin Coating 31711.5.1.2 Blade Coating 31911.5.1.3 Slot Die Coating 32011.5.1.4 Screen Printing 32111.5.1.5 Spray Coating 32411.5.1.6 Laser Patterning 32411.5.1.7 Roll‐to‐Roll Deposition 32511.5.1.8 Other Large Area Deposition Techniques 32611.6 Summary 329Acknowledgement 329References 32912 Hot Electrons Role in Biomolecule‐based Quantum Dot Hybrid Solar Cells 339T. Pazhanivel, G. Bharathi, D. Nataraj, R. Ramesh, and D. Navaneethan12.1 Introduction 33912.2 Classifications of Solar Cells 34112.2.1 Inorganic Solar Cells 34212.2.2 Organic Solar Cells (OSCs) 34312.2.3 Hybrid Solar Cells 34412.3 Main Losses in Solar Cells 34412.3.1 Recombination Loss 34512.3.2 Contact Losses 34512.4 Hot Electron Concept in Materials 34612.5 Methodology 34712.5.1 Hot Injection Method 34812.5.1.1 Nucleation and Growth Stages 34912.5.1.2 Merits of this Method 35012.6 Material Synthesis 35012.6.1 CdSe QD Preparation 35012.6.2 QD–βC Hybrid Formation 35112.7 Identification of Hot Electrons 35112.7.1 Photoluminescence (PL) Spectrum 35112.7.2 Time‐correlated Single Photon Counting (TCSPC) 35512.7.3 Transient Absorption 35712.8 Quantum Dot Sensitized Solar Cells 36012.8.1 Working Principle 36012.8.2 Device Preparation 36112.8.2.1 Preparation of TiO2 Nanoparticle Electrode 36112.8.2.2 QDs Deposition on TiO2 Nanoparticle 36212.8.2.3 Counterelectrode and Assembly of QDSSC 36212.8.3 Performance 36212.9 Conclusion 363References 363Index 369