Solar Cell Materials

This book presents a comparison of solar cell materials, including both new materials based on organics, nanostructures and novel inorganics and developments in more traditional photovoltaic materials. It surveys the materials and materials trends in the field including third generation solar cells (multiple energy level cells, thermal approaches and the modification of the solar spectrum) with an eye firmly on low costs, energy efficiency and the use of abundant non-toxic materials.

Auteur

Dr. Gavin Conibeer is Deputy Director of the Centre of Excellence for Advanced Silicon Photovoltaics and Photonics at the University of New South Wales (UNSW, Australia). He has a BSc (Eng) and MSc (London) and received his PhD at Southampton University (UK). His research interests include third generation photovoltaics, hot carrier cooling in semiconductors, phonon dispersion modulation in nanostructures, high efficiency thermoelectric devices and photoelectrochemical generation of hydrogen. As well as numerous publications, Dr. Conibeer has also given a short course on Third Generation Photovoltaics at UNSW and a unit on Photovoltaics for the Open University (UK).

Professor Arthur Willoughby is currently Professor Emeritus at the University of Southampton having retired from Southampton after many years teaching. He holds a BSc and PhD in Engineering, both from Imperial College, and was head of Engineering Materials at Southampton for more than 10 years. With research interests focussed around semiconductor materials, Arthur Willoughby is founding editor of Journal of Materials Science: Materials in Electronics for Springer as well as principal editor for Materials Letters for Elsevier. He has written multiple journal articles as well as book chapters for Springer and MRS, and is a series editor for the Wiley Series in Materials for Electronic and Optoelectronic Applications.

Contenu

Series Preface xiii

List of Contributors xv

1 Introduction 1
*Gavin Conibeer and Arthur Willoughby*

1.1 Introduction 1

1.2 The Sun 1

1.3 Book Outline 3

References 4

2 Fundamental Physical Limits to Photovoltaic Conversion 5
*J.F. Guillemoles*

2.1 Introduction 5

2.2 Thermodynamic Limits 8

2.2.1 The Sun is the Limit 9

2.2.2 Classical Thermodynamics Analysis of Solar Energy Conversion 10

2.3 Limitations of Classical Devices 12

2.3.1 Detailed Balance and Main Assumptions 13

2.3.2 p-n Junction 14

2.3.3 The Two-Level System Model 17

2.3.4 Multijunctions 19

2.4 Fundamental Limits of Some High-Efficiency Concepts 22

2.4.1 Beyond Unity Quantum Efficiency 23

2.4.2 Beyond Isothermal Conversion: Hot-Carrier Solar Cells (HCSC) 29

2.4.3 Beyond the Single Process/ Photon: Photon Conversion 32

2.5 Conclusion 33

Note 33

References 33

3 Physical Characterisation of Photovoltaic Materials 35
*Daniel Bellet and Edith Bellet-Amalric*

3.1 Introduction 35

3.2 Correspondence between Photovoltaic Materials Characterisation Needs and Physical Techniques 35

3.3 X-Ray Techniques 36

3.3.1 X-Ray Diffraction (XRD) 37

3.3.2 Grazing-Incidence X-Ray Diffraction (GIXRD) 40

3.3.3 X-Ray Reflectivity (XRR) 42

3.3.4 Other X-Ray Techniques 44

3.4 Electron Microscopy Methods 45

3.4.1 ElectronSpecimen Interactions and Scanning Electron Microscopy (SEM) 48

3.4.2 Electron Backscattering Diffraction (EBSD) 49

3.4.3 Transmission Electron Microscopy (TEM) 51

3.4.4 Electron Energy Loss Spectroscopy (EELS) 52

3.5 Spectroscopy Methods 53

3.5.1 X-Ray Photoelectron Spectroscopy (XPS) 53

3.5.2 Secondary Ion Mass Spectrometry (SIMS) 55

3.5.3 Rutherford Backscattering Spectrometry (RBS) 56

3.5.4 Raman Spectroscopy 56

3.5.5 UV-VIS-NIR Spectroscopy 58

3.6 Concluding Remarks and Perspectives 59

Acknowledgements 60

References 60

4 Developments in Crystalline Silicon Solar Cells 65
*Martin A. Green*

4.1 Introduction 65

4.2 Present Market Overview 66

4.3 Silicon Wafers 67

4.3.1 Standard Process 67

4.3.2 Multicrystalline Silicon Ingots 70

4.3.3 Ribbon Silicon 71

4.4 Cell Processing 73

4.4.1 Screen-Printed Cells 73

4.4.2 Buried-Contact and Laser Doped, Selective-Emitter Solar Cells 76

4.4.3 HIT Cell 77

4.4.4 Rear-Contact Cell 78

4.4.5 PERL Solar Cell 79

4.5 Conclusion 82

Acknowledgements 82

References 82

5 Amorphous and Microcrystalline Silicon Solar Cells 85
*R.E.I. Schropp*

5.1 Introduction 85

5.2 Deposition Methods 87

5.2.1 Modifications of Direct PECVD Techniques 88

5.2.2 Remote PECVD Techniques 89

5.2.3 Inline HWCVD Deposition 91

5.3 Material Properties 91

5.3.1 Protocrystalline Silicon 92

5.3.2 Microcrystalline or Nanocrystalline Silicon 93

5.4 Single-Junction Cell 96

5.4.1 Amorphous (Protocrystalline) Silicon Cells 98

5.4.2 Microcrystalline (c-Si:H) Silicon Cells 99

5.4.3 Higher Deposition Rate 101

5.5 Multijunction Cells 102

5.6 Modules and Production 103

Acknowledgments 106

References 106

6 III-V Solar Cells 113
*N.J. Ekins-Daukes*

6.1 Introduction 113

6.2 Homo- and Heterojunction III-V Solar Cells 115

6.2.1 GaAs Solar Cells 117

6.2.2 InP Solar Cells 120

6.2.3 InGaAsP 121 6.2.4 GaN 121&...