Solar Cell Materials

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.

“All in all it is a magnificent book that I take pride in having on my bookshelf.”  (Energy Technology, 13 October 2014)

• Series Preface xiiiList of Contributors xv1 Introduction 1Gavin Conibeer and Arthur Willoughby1.1 Introduction 11.2 The Sun 11.3 Book Outline 3References 42 Fundamental Physical Limits to Photovoltaic Conversion 5J.F. Guillemoles2.1 Introduction 52.2 Thermodynamic Limits 82.2.1 The Sun is the Limit 92.2.2 Classical Thermodynamics Analysis of Solar Energy Conversion 102.3 Limitations of Classical Devices 122.3.1 Detailed Balance and Main Assumptions 132.3.2 p-n Junction 142.3.3 The Two-Level System Model 172.3.4 Multijunctions 192.4 Fundamental Limits of Some High-Efficiency Concepts 222.4.1 Beyond Unity Quantum Efficiency 232.4.2 Beyond Isothermal Conversion: Hot-Carrier Solar Cells (HCSC) 292.4.3 Beyond the Single Process/ Photon: Photon Conversion 322.5 Conclusion 33Note 33References 333 Physical Characterisation of Photovoltaic Materials 35Daniel Bellet and Edith Bellet-Amalric3.1 Introduction 353.2 Correspondence between Photovoltaic Materials Characterisation Needs and Physical Techniques 353.3 X-Ray Techniques 363.3.1 X-Ray Diffraction (XRD) 373.3.2 Grazing-Incidence X-Ray Diffraction (GIXRD) 403.3.3 X-Ray Reflectivity (XRR) 423.3.4 Other X-Ray Techniques 443.4 Electron Microscopy Methods 453.4.1 Electron–Specimen Interactions and Scanning Electron Microscopy (SEM) 483.4.2 Electron Backscattering Diffraction (EBSD) 493.4.3 Transmission Electron Microscopy (TEM) 513.4.4 Electron Energy Loss Spectroscopy (EELS) 523.5 Spectroscopy Methods 533.5.1 X-Ray Photoelectron Spectroscopy (XPS) 533.5.2 Secondary Ion Mass Spectrometry (SIMS) 553.5.3 Rutherford Backscattering Spectrometry (RBS) 563.5.4 Raman Spectroscopy 563.5.5 UV-VIS-NIR Spectroscopy 583.6 Concluding Remarks and Perspectives 59Acknowledgements 60References 604 Developments in Crystalline Silicon Solar Cells 65Martin A. Green4.1 Introduction 654.2 Present Market Overview 664.3 Silicon Wafers 674.3.1 Standard Process 674.3.2 Multicrystalline Silicon Ingots 704.3.3 Ribbon Silicon 714.4 Cell Processing 734.4.1 Screen-Printed Cells 734.4.2 Buried-Contact and Laser Doped, Selective-Emitter Solar Cells 764.4.3 HIT Cell 774.4.4 Rear-Contact Cell 784.4.5 PERL Solar Cell 794.5 Conclusion 82Acknowledgements 82References 825 Amorphous and Microcrystalline Silicon Solar Cells 85R.E.I. Schropp5.1 Introduction 855.2 Deposition Methods 875.2.1 Modifications of Direct PECVD Techniques 885.2.2 Remote PECVD Techniques 895.2.3 Inline HWCVD Deposition 915.3 Material Properties 915.3.1 Protocrystalline Silicon 925.3.2 Microcrystalline or Nanocrystalline Silicon 935.4 Single-Junction Cell 965.4.1 Amorphous (Protocrystalline) Silicon Cells 985.4.2 Microcrystalline (μc-Si:H) Silicon Cells 995.4.3 Higher Deposition Rate 1015.5 Multijunction Cells 1025.6 Modules and Production 103Acknowledgments 106References 1066 III-V Solar Cells 113N.J. Ekins-Daukes6.1 Introduction 1136.2 Homo- and Heterojunction III-V Solar Cells 1156.2.1 GaAs Solar Cells 1176.2.2 InP Solar Cells 1206.2.3 InGaAsP 1216.2.4 GaN 1216.3 Multijunction Solar Cells 1226.3.1 Monolithic Multijunction Solar Cells 1236.3.2 Mechanically Stacked Multijunction Solar Cells 1296.4 Applications 1316.4.1 III-V Space Photovoltaic Systems 1316.4.2 III-V Concentrator Photovoltaic Systems 1326.5 Conclusion 134References 1347 Chalcogenide Thin-Film Solar Cells 145M. Paire, S. Delbos, J. Vidal, N. Naghavi and J.F. Guillemoles7.1 Introduction 1457.2 CIGS 1487.2.1 Device Fabrication 1487.2.2 Material Properties 1627.2.3 Device Properties 1717.2.4 Outlook 1817.3 Kesterites 1857.3.1 Advantages of CZTS 1857.3.2 Crystallographic and Optoelectronic Properties 1877.3.3 Synthesis Strategies 190Acknowledgements 196References 1968 Printed Organic Solar Cells 217Claudia Hoth, Andrea Seemann, Roland Steim, Tayebeh Ameri, Hamed Azimi and Christoph J. Brabec8.1 Introduction 2178.2 Materials and Morphology 2188.2.1 Organic Semiconductors 2198.2.2 Control of Morphology in oBHJ Solar Cells 2248.2.3 Monitoring Morphology 2338.2.4 Numerical Simulations of Morphology 2358.2.5 Alternative Approaches to Control the Morphology 2358.3 Interfaces in Organic Photovoltaics 2378.3.1 Origin of Voc 2378.3.2 Determination of Polarity-Inverted and Noninverted Structure 2388.3.3 Optical Spacer 2398.3.4 Protection Layer between the Electrode and the Polymer 2408.3.5 Selective Contact 2408.3.6 Interface Material Review for OPV Cells 2408.4 Tandem Technology 2438.4.1 Theoretical Considerations 2438.4.2 Review of Experimental Results 2488.4.3 Design Rules for Donors in Bulk-Heterojunction Tandem Solar Cells 2558.5 Electrode Requirements for Organic Solar Cells 2578.5.1 Materials for Transparent Electrodes 2588.5.2 Materials for Nontransparent Electrodes 2638.6 Production of Organic Solar Cells 2658.7 Summary and Outlook 273References 2739 Third-Generation Solar Cells 283Gavin Conibeer9.1 Introduction 2839.2 Multiple-Energy-Level Approaches 2859.2.1 Tandem Cells 2859.2.2 Multiple-Exciton Generation (MEG) 2919.2.3 Intermediate-Band Solar Cells (IBSC) 2939.3 Modification of the Solar Spectrum 2949.3.1 Downconversion, QE > 1 2949.3.2 Upconversion of Below-Bandgap Photons 2979.4 Thermal Approaches 3029.4.1 Thermophotovoltaics (TPV) 3039.4.2 Thermophotonics 3039.4.3 Hot-Carrier Cells 3039.5 Other Approaches 3089.5.1 Nonreciprocal Devices 3089.5.2 Quantum Antennae – Light as a Wave 3089.6 Conclusions 309Acknowledgements 309References 310Concluding Remarks 315Gavin Conibeer and Arthur WilloughbyIndex 319