Preface to the First International Edition xv

Preface to the Second International Edition xvii

Abbreviations xix

1 Introduction 1

1.1 Introduction 1

1.1.1 Why Photovoltaics? 1

1.1.2 Who Should Read This Book? 2

1.1.3 Structure of the Book 2

1.2 What Is Energy? 3

1.2.1 Definition of Energy 3

1.2.2 Units of Energy 4

1.2.3 Primary, Secondary, and End Energy 5

1.2.4 Energy Content of Various Substances 6

1.3 Problems with Today's Energy Supply 7

1.3.1 Growing Energy Requirements 7

1.3.2 Tightening of Resources 8

1.3.3 Climate Change 9

1.3.4 Hazards and Disposal 11

1.4 Renewable Energies 11

1.4.1 The Family of Renewable Energies 11

1.4.2 Advantages and Disadvantages of Renewable Energies 12

1.4.3 Previous Development of Renewable Energies 13

1.5 Photovoltaics - The Most Important in Brief 13

1.5.1 What Does "Photovoltaics" Mean? 13

1.5.2 What Are Solar Cells and Solar Modules? 14

1.5.3 How Is a Typical Photovoltaic Plant Structured? 14

1.5.4 What Does a Photovoltaic Plant "Bring?" 15

1.6 History of Photovoltaics 16

1.6.1 How It all Began 16

1.6.2 The First Real Solar Cells 17

1.6.3 From Space to Earth 19

1.6.4 From Toy to Energy Source 20

2 Solar Radiation 23

2.1 Properties of Solar Radiation 23

2.1.1 Solar Constant 23

2.1.2 Spectrum of the Sun 23

2.1.3 Air Mass 25

2.2 Global Radiation 25

2.2.1 Origin of Global Radiation 25

2.2.2 Contributions of Diffuse and Direct Radiation 26

2.2.3 Global Radiation Maps 28

2.3 Calculation of the Position of the Sun 30

2.3.1 Declination of the Sun 30

2.3.2 Calculating the Path of the Sun 32

2.4 Radiation on Tilted Surfaces 35

2.4.1 Radiation Calculation with the Three-component Model 35

2.4.1.1 Direct Radiation 35

2.4.1.2 Diffuse Radiation 36

2.4.1.3 Reflected Radiation 37

2.4.2 Radiation Estimates with Diagrams and Tables 38

2.4.3 Yield Gain through Tracking 41

2.5 Radiation Availability and World Energy Consumption 41

2.5.1 The Solar Radiation Energy Cube 41

2.5.2 The Sahara Miracle 45

3 Fundamentals of Semiconductor Physics 47

3.1 Structure of a Semiconductor 47

3.1.1 Bohr's Atomic Model 47

3.1.2 Periodic Table of Elements 49

3.1.3 Structure of the Silicon Crystal 49

3.1.4 Compound Semiconductors 49

3.2 Band Model of a Semiconductor 51

3.2.1 Origin of Energy Bands 51

3.2.2 Differences in Isolators, Semiconductors, and Conductors 53

3.2.3 Intrinsic Carrier Concentration 53

3.3 Charge Transport in Semiconductors 55

3.3.1 Field Currents 55

3.3.2 Diffusion Currents 56

3.4 Doping of Semiconductors 57

3.4.1 n-Doping 57

3.4.2 p-Doping 58

3.5 The p-n Junction 59

3.5.1 Principle of Method of Operation 59

3.5.2 Band Diagram of the p-n Junction 61

3.5.3 Behavior with Applied Voltage 62

3.5.4 Diode Characteristics 63

3.6 Interaction of Light and Semiconductors 64

3.6.1 Phenomenon of Light Absorption 64

3.6.1.1 Absorption Coeffcient 65

3.6.1.2 Direct and Indirect Semiconductors 65

3.6.2 Light Reflection on Surfaces 67

3.6.2.1 Reflection Factor 67

3.6.2.2 Antireflection Coati