Next-Generation Solar Cells: Principles and Materials

Building a sustainable energy system is one of the great challenges of our time that has prompted both academia and industry to seek alternative energy and renewable energy solutions. Recently, advanced materials and technologies for next-generation solar cells have been exploited to develop economically viable, high-performance solar cells. This book addresses the principles and materials for the development of next-generation solar cells for a sustainable global society. It reviews the structures, working principles, and limitations of solar cells as well as the methods to improve their power-conversion efficiency. It introduces generations of cells as photovoltaic devices, including third-generation solar cells such as organic solar cells, quantum dot solar cells, and organic–inorganic hybrid solar cells. It focuses on the emerging perovskite solar cells (PSCs) and deals with their cell configuration, transport materials, and fabrication processes in detail.

• Preface
• 1. Electromagnetic Radiation
• 1.1 Light and Photon
• 1.1 Photometry
• 1.3 Blackbody Radiation
• 1.4 Planck’s Radiation Law
• 1.1 Solar Spectrum
• References
• Problems
• 2. Physics and Properties of Semiconductors
• 2.1 Atomic Structure of Semiconductor
• 2.2 Carrier Concentration
• 2.3 Doping
• 2.4 Drift and Mobility
• 2.5 Diffusion
• 2.6 Recombination
• 2.7 p-n Junction
• 2.8 Optical Properties
• 2.8.1 Absorption: Direct-Bandgap and Indirect-Bandgap Transitions
• 2.8.2 Luminescence Emission
• 2.8.3 Quantum Efficiency
• References
• Problems
• 3. Working Principles and Limitations of Solar Cells
• 3.1 Basic Structure and Working Principle of Solar Cells
• 3.1.1 Basic Structure of Solar Cells
• 3.1.2 Solar Cell Working Principles
• 3.2 Limitations and Improvements of Energy Conversion in Solar Cells
• 3.2.1 Efficiency Limitation Factors in Solar Cells
• 3.3 Maximum Efficiency of Solar Cells
• 3.4 Improvement of the Efficiency of Solar Cells
• 3.4.1 Tandem Solar Cells
• 3.4.2 Concentrator Solar Cells
• 3.4.3 Up- and Down-Conversion of Photons
• 3.5 Photovoltaic Generations
• References
• Problems
• Chapter 4 Generations of Solar Cells
• 4.1 First Generation: Solar Cells Based on Silicon Wafers
• 4.1.1 Basic Material
• 4.1.2 Crystalline Silicon Solar Cell
• 4.1.3 Solar Cell Performance
• 4.1.4 Cell Fabrication Technology
• 4.2 Second Generation: Thin-Film Solar Cells
• 4.2.1 Materials
• 4.2.2 Si-Based Thin-Film Solar Cells
• 4.2.3 Chalcopyrite-Based Solar Cells
• 4.2.4 Cadmium Telluride (CdTe) Solar Cells
• 4.3 Third Generation: Organic, Quantum Dot, Organometallic Solar Cells
• 4.3.1 Organic Solar Cells
• 4.3.2 Quantum Dot Solar Cell
• 4.3.3 Organic–Inorganic Hybrid Solar Cells
• References
• Problems
• 5. Organic Solar Cells
• 5.1 Organic Semiconductors
• 5.2 Basic Operation Principles and Physical Mechanism
• 5.2.1 Absorption and Exciton
• 5.2.2 Diffusion and Dissociation
• 5.3 Organic Solar Cell Configurations
• 5.3.1 Planar Solar Cells
• 5.3.2 Bulk Heterojunction Solar Cells
• 5.3.3 Polymer Solar Cells
• 5.3.4 All-Polymer Solar Cells
• 5.3.5 Ternary Polymer Solar Cells
• 5.3.6 Organic Tandem Solar Cells
• 5.4 Charge Dynamics in Polymer Solar Cells
• 5.4.1 Charge Dynamics Measurements
• 5.4.2 Exciton Dissociation and Charge Generation
• 5.4.3 Charge Recombination
• 5.5 Dye-Sensitized Solar Cells
• 5.5.1 Structure of DSSC
• 5.5.3 Performance of DSSC
• 5.5.4 Limitations of DSSCs
• References
• Problems
• 6. Quantum Dot Solar Cells
• 6.1 Physical Properties of Quantum Dot
• 6.1.1 What Are Quantum Dots?
• 6.1.2 Synthesis of Quantum Dots
• 6.1.3 Optical and Electronic Properties of Quantum Dots
• 6.1.4 Application of Quantum Dots
• 6.2 Quantum Dots Based Solar Cells
• 6.2.1 Quantum Dots Solar Cell Configuration
• 6.2.2 Basic Operation Principles and Physical Mechanism
• 6.3 Quantum Dot/Semiconductor Heterojunction Solar Cells
• 6.3.1 Schottky Junction Solar Cells
• 6.3.2 Depleted Planar Heterostructure Quantum Dot Solar Cells
• 6.3.3 Depleted Bulk Heterojunction Quantum Dot Solar Cells
• 6.4 Quantum Dots Sensitized Solar Cells
• 6.4.1 Structure and Working Principles of QDSSC
• 6.4.2 Components of QDSSC
• Problems
• 7. Organic—Inorganic Hybrid Solar Cells
• 7.1 Graphene-Based Hybrid Solar Cells
• 7.2 Polymer–Quantum Dot Hybrid Solar Cells
• 7.2.1 Material Aspects
• 7.2.2 Hybrid Bulk Heterojunction Solar Cells with Large Bandgap Nanocrystals
• 7.2.3 Hybrid Bulk Heterojunction Solar Cells with Low-Bandgap Nanocrystals
• 7.2.4 Limiting Factors of Polymer—QD Hybrid Solar Cells
• 7.2.5 Interfacial Engineering in Polymer–QD Hybrid Solar Cells
• 7.3 Charge-Transport Materials for Hybrid Solar Cells
• 7.3.1 Metal Oxide–Based Charge-Transport Materials
• 8. Perovskite Solar Cells
• 8.1 What Are Perovskites and Their Properties?
• 8.1.1 Organic–Inorganic Hybrid Perovskites
• 8.1.2 Low-Dimensional Perovskites
• 8.1.3 All-Inorganic Perovskites
• 8.2 Perovskite Composition Engineering
• 8.2.1 A-Site Doping
• 8.2.2 B-Site Doping
• 8.2.3 X-Site Doping
• 8.3 History of Perovskite Solar Cell
• 8.4 Basic Working Principles
• References
• Problems
• 9. Structures, Transport Materials, and Deposition Methods for Perovskite Solar Cells
• 9.1 Perovskite Solar Cell Configurations
• 9.1.1 n-i-p Structure
• 9.1.2 p-i-n Structure
• 9.1.3 Hole-Conductor Free Perovskite Solar Cells
• 9.1.4 Flexible Perovskite Solar Cells
• 9.2 Transport Materials for Perovskite Solar Cells
• 9.2.1 Electron-Transport Materials
• 9.3.2 Vapor-Assisted Deposition
• 9.3.3 Printing Deposition
• References
• Problems
• 10. Defects and Ions Migration in Perovskite Solar Cells
• 10.1 Nature of Defects
• 1 Point defects
• 2 Impurity defects
• 3 Planar defects
• 10.2 Defects and Charge-Transport Processes
• 10.3 Formation of Intrinsic Defects
• 10.4 Light Soaking and Trap Filling
• 10.5 Extrinsic Defects
• 10.6 Techniques to the Probe Defect States
• 10.7 Ions Migration
• 10.8 Ions Migration in Operating Solar Cell
• References
• Problems
• 11. Quantum Dots, Tandem, and Lead-Free Perovskite Solar Cells
• 11.1 Perovskite Quantum Dots Solar Cells
• 11.1.1 From Perovskite Thin Films to Quantum Dots
• 11.1.2 Crystal Structure and Properties of Perovskite QDs
• 11.1.3 Emerging of Perovskite QDSCs
• 11.1.4 Methods of Enhancing the Device Performance of PQDSCs
• 11.2 Perovskite Tandem Solar Cells
• 11.2.1 Working Principles of Tandem Solar Cells
• 11.2.2 Perovskite Tandem Solar Cells
• 11.3.2 Tin-Based Perovskites
• 11.3.3 Germanium-Based Perovskites
• 11.3.4 Antimony- and Bismuth-Based Perovskites
• 11.3.5 Halide Double Perovskites
• References
• Problems
• 12. Composites-Based Efficient and Stable Perovskite Solar Cells with Interface Engineering
• 12.1 Organic Materials–Based Perovskite Composites
• 12.1.1 Small-Molecule-Based Perovskite Composites
• 12.1.2 Polymer-Based Perovskite Composites
• 12.1.3 Ammonium-Based Perovskite Composites
• 12.1.4 Low-Dimensional/Three-Dimensional Perovskite Composites
• 12.2 Inorganic Material–Based Perovskite Composites
• 12.2.1 Metal Oxide–Based Perovskite Composites
• 12.2.2 Carbon-Based Perovskite Composites
• 12.2.3 Semitransparent PSCs with Metal Oxide–Based Composites
• 12.2.4 Other Inorganic Halides–Based Perovskite Composites
• 12.3 Stability Enhancement with Interface Engineering
• 12.3.1 Why Is Interface Engineering Needed?
• 12.3.2 Interface Engineering at TCO/ETL Interface
• 12.3.3 Interface Engineering at ETL/AL Interface
• 12.3.4 Interface Engineering at AL/HTL Interface
• 12.3.5 Interface Engineering at HTL/Electrode Interface
• 12.3.6 Interface Engineering at Multi-Interface Locations
• 12.4 Composite-Based Charge-Transport Materials
• 12.4.1 Composite-Based Electron-Transport Layer
• 12.4.2 Composite-Based Hole-Transport Layer
• References
• Problems
• 13. Characterization of Solar Cell Materials and Devices
• 13.1 Spectroscopic Techniques
• 13.2 Chemical Analysis
• 13.2.1 Fourier Transform Infrared (FTIR) Spectroscopy
• 13.2.2 X-ray Photoelectron Spectroscopy (XPS)
• 13.2.3 Energy-Dispersive X-ray Spectroscopy
• 13.3 Physical Analysis
• 13.3.1 Raman Spectroscopy
• 13.3.2 Photoluminescence (PL) Spectroscopy
• 13.3.3 UV–Vis Absorption Spectroscopy
• 13.3.4 Ultraviolet Photoelectron Spectroscopy (UPS)
• 13.4 Structural Analysis
• 13.4.1 X-ray Diffraction Analysis
• 13.4.2 Electron Microscopy
• 13.5.3 Impedance Spectroscopy
• 13.5.4 Space-Charge-Limited Current
• References
• Problems
• Index