Photon Management in Solar Cells

Ralf B. Wehrspohn studied physics at the University of Oldenburg, Germany, and received his Ph.D. degree from the Ecole Polytechnique in Paris in 1997. Until 1999 he worked on thin-film transistors for AMLCDs at Philips Research. From 1999 until 2003 he led the Porous Materials/Photonic Crystals group at the Max Planck Institute of Microstructure Physics in Halle, after which he held a chair at the Physics department of the University of Paderborn for three years. Since 2006, he has been the director of the Fraunhofer-Institute for Mechanics of Materials and a Professor of Physics at the Martin-Luther-University Halle-Wittenberg. Professor Wehrspohn was awarded the Maier-Leibnitz Prize of the German Science Foundation in 2003. Uwe Rau is full professor at RWTH Aachen (Faculty Electrical Engineering and Computer Science, chair of photovoltaics) since 2007 and is head of the energy research IEF-55 photovoltaic institute at the research center in Julich. He obtained his PhD 1991 from Physical Institute of the University Tubingen (Prof. Huebener) and was scientific group leader from 1995-2007 at the University Bayreuth and Stuttgart. Andreas Gombert is chief technology officer of Concentrix Solar, Freiburg, Germany, a division of the Soitec Group.

Preface

CURRENT CONCEPTS FOR OPTICAL PATH ENHANCEMENT IN SOLAR CELLS
Introduction
Planar Antireflection Coatings
Optical Path Enhancement in the Ray Optical Limit
Scattering Structures for Optical Path Enhancement
Resonant Structures for Optical Path Enhancement
Ultra-Light Trapping
Energy-Selective Structures as Intermediate Reflectors for Optical Path Enhancement in Tandem Solar Cells
Comparison of the Concepts
Conclusions

THE PRINCIPLE OF DETAILED BALANCE AND THE OPTO-ELECTRONIC PROPERTIES OF SOLAR CELLS
Introduction
Opto-Electronic Reciprocity
Connection to Other Reciprocity Theorems
Applications of the Opto-Electronic Reciprocity Theorem
Limitations to the Opto-Electronic Reciprocity Theorem
Conclusions

REAR SIDE DIFFRACTIVE GRATINGS FOR SILICON WAFER SOLAR CELLS
Introduction
Principle of Light Trapping with Gratings
Fundamental Limits of Light Trapping with Gratings
Simulation of Gratings in Solar Cells
Realization
Topographical Characterization
Summary

RANDOMLY TEXTURED SURFACES
Introduction
Methodology
Properties of an Isolated Interface
Single-Junction Solar Cell
Intermediate Layer in Tandem Solar Cells
Conclusions

BLACK SILICON PHOTOVOLTAICS
Introduction
Optical Properties and Light Trapping Possibilities
Surface Passivation of Black Silicon
Black Silicon Solar Cells

CONCENTRATOR OPTICS FOR PHOTOVOLTAIC SYSTEMS
Fundamentals of Solar Concentration
Optical Designs
Silicone on Glass Fresnel Lenses
Considerations on Concentrators in HCPV Systems
Conclusions

LIGHT-TRAPPING IN SOLAR CELLS BY DIRECTIONALLY SELECTIVE FILTERS
Introduction
Theory
Filter Systems
Experimental Realization
Summary and Outlook

LINEAR OPTICS OF PLASMONIC CONCEPTS TO ENHANCE SOLAR CELL PERFORMANCE
Introduction
Metal Nanoparticles
Surface-Plasmon Polaritons
Front-Side Plasmonic Nanostructures
Rear-Side Plasmonic Nanostructures
Further Concepts
Summary

UP-CONVERSION MATERIALS FOR ENHANCED EFFICIENCY OF SOLAR CELLS
Introduction
Up-Conversion in Er3+-Doped ZBLAN Glasses
Up-Conversion in Er3+-Doped Beta-NaYF4
Simulating Up-Conversion with a Rate-Equation Model
Increasing Up-Conversion Efficiencies
Conclusion

DOWN-CONVERSION IN RARE-EARTH DOPED GLASSES AND GLASS CERAMICS
Introduction
Physical Background
Down-Conversion in ZBLAN Glasses and Glass Ceramics
Down-Conversion in Sm-Doped Borate Glasses for High-Efficiency CdTe Solar Cells
Summary

FLUORESCENT CONCENTRATORS FOR PHOTOVOLTAIC APPLICATIONS
Introduction
The Theoretical Description of Fluorescent Concentrators
Materials for Fluorescent Concentrators
Experimentally Realized Fluorescent Concentrator Systems
Conclusion

LIGHT MANAGEMENT IN SOLAR MODULES
Introduction
Fundamentals of Light Management in Solar Modules
Technological Solutions for Minimized Optical Losses in Solar Modules
Outlook

Index