Electro-Optical Effects to Visualize Field and Current Distributions in Semiconductors (eBook)

Preface 6
Contents 8
1 Introduction 10
1.1 A Brief History 10
1.2 Negative Resistance Regimes 13
1.3 Summary and Emphasis 14
2 High-Field Domains 16
2.1 Field-of-Direction Analysis 16
Cathode-Adjacent and Anode-Adjacent Domains 20
Franz–Keldysh Effect to Directly Observe High-Field Domains 24
2.1.1 Electron Mobility as Function of the Field 25
2.1.2 Drift Velocity Saturation at Higher Fields 27
Incomplete Drift Saturation 28
2.2 Pseudo-Cathodes and the Field of Directions 28
2.2.1 Doping-dependence of the Field Quenching 31
2.2.2 Work Function Dependence on Photoconductivity 35
2.3 Summary and Emphasis 36
3 Moving High-Field Domains 39
3.1 Stationary and Moving High-Field Domains 39
3.1.1 Self-Sustained Free Moving High-Field Domains 41
3.1.2 Unstable Moving High-Field Domains 43
Separating Domains as Sensitive Tools to Observe Crystal Inhomogeneities 45
Conditions for Breaking Up of Domains 47
Moving Sub-Domains 50
3.2 Stability Criteria and Moving High-Field Domains 50
3.2.1 Trap-Controlled Kinetics 51
Singular Point Analysis 52
Field-of-Direction Analysis for Kinetic Solutions 55
Periodic Solutions for Trap-Controlled Domains 56
3.3 Summary and Emphasis 58
4 Negative Differential Conductivity Caused by Mobility 60
4.1 Gunn Domains 60
4.1.1 The Gunn Effect 62
Field-of-Direction Analysis of Gunn-Domains 62
Moving Domain-Type Solutions 63
Current Oscillations 65
4.2 Summary and Emphasis 65
5 Negative Differential Conductivity in Other Materials 66
5.1 Domain Instability 68
5.2 Field Domains in Superlattices 71
5.3 Other Examples of Stationary and Moving High-FieldDomains 76
5.4 Summary and Emphasis 78
6 Current Channels 80
6.1 Initiation of Current Channels 81
6.1.1 Current Channels in Dielectrics and Devices 83
6.1.2 Thermo-Optical Method to View Current Channels 83
6.1.3 Current Channel Modeling 85
6.2 General Discussion of Current Channels or Filaments 90
6.2.1 Filamentary Instability 91
6.2.2 Stationary Filaments 92
6.2.3 Spatiotemporal Dynamics of Filaments 95
6.3 Examples of More Complex Filament Formation 98
6.3.1 Impurity Breakdown in n-GaAs 98
6.4 Summary and Emphasis 104
A Educational Films 106
A.1 High-Field Domain and Current Channel Kinetics 106
A.2 High-Field Domain Analysis 106
A.2.1 Electro-Optical Tools 106
A.2.2 Model Semiconductor Cadmium Sulfide 107
A.3 The Film 108
A.3.1 Field Inhomogeneities 108
A.3.2 Current Distributions 108
References 111
Index 124