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索书号 61/M862
Table of Contents
Preface XIII
1 General Properties of Nitrides 1
1.1 Crystal Structure of Nitrides 1
1.2 Gallium Nitride 5
1.3 Aluminum Nitride 6
1.4 Indium Nitride 10
1.5 AlGaN Alloy 13
1.6 InGaN Alloy 14
1.7 AlInN Alloy 14
1.8 InAlGaN Quaternary Alloy 15
1.9 Electronic Band Structure and Polarization Effects 18
1.9.1 Introduction 18
1.9.2 General Strain Considerations 22
1.9.3 kp Theory and the Quasicubic Model 23
1.9.4 Temperature Dependence of Wurtzite GaN Bandgap 26
1.9.5 Sphalerite (Zincblende) GaN 26
1.9.6 AlN 28
1.9.6.1 Wurtzite AlN 28
1.9.6.2 Zincblende AlN 28
1.9.7 InN 29
1.10 Polarization Effects 31
1.10.1 Piezoelectric Polarization 32
1.10.2 Spontaneous Polarization 35
1.10.3 Nonlinearity of Polarization 35
1.10.3.1 Nonlinearities in Piezoelectric Polarization 42
1.10.4 Polarization in Heterostructures 46
1.10.4.1 Ga-Polarity Single AlGaN–GaN Interface 51
1.10.4.2 Polarization in Quantum Wells 56
1.11 Nonpolar and Semipolar Orientations 59
2 Doping: Determination of Impurity and Carrier Concentrations 63
2.1 Introduction 63
2.2 Doping 63
2.3 Formation Energy of Defects 65
2.3.1 Hydrogen and Impurity Trapping at Extended Defects 67
2.4 Doping Candidates 69
2.5 Free Carriers 70
2.6 Binding Energy 70
2.7 Conductivity Type: Hot Probe and Hall Measurements 71
2.8 Measurement of Mobility 71
2.9 Semiconductor Statistics, Density of States, and Carrier Concentration 74
2.10 Charge Balance Equation and Carrier Concentration 78
2.10.1 n-Type Semiconductor 79
2.10.2 p-Type Semiconductor 84
2.11 Capacitance–Voltage Measurements 87
Appendix 2.A. Fermi Integral 94
Further Reading 95
3 Metal Contacts 97
3.1 Metal–Semiconductor Band Alignment 97
3.2 Current Flow in Metal–Semiconductor Junctions 101
3.3 Ohmic Contact Resistance 107
3.3.1 Specific Contact Resistivity 107
3.4 Semiconductor Resistance 108
3.4.1 Determination of the Contact Resistivity 109
Further Reading 113
4 Carrier Transport 115
4.1 Introduction 115
4.2 Carrier Scattering 117
4.2.1 Impurity Scattering 118
4.2.2 Acoustic Phonon Scattering 120
4.2.2.1 Deformation Potential Scattering 121
4.2.2.2 Piezoelectric Scattering 124
4.2.3 Optical Phonon Scattering 126
4.2.3.1 Nonpolar Optical Phonon Scattering 126
4.2.3.2 Polar Optical Phonon Scattering 127
4.2.4 Alloy Scattering and Dislocation Scattering 134
4.3 Calculated Mobility of GaN 143
4.4 Scattering at High Fields 147
4.4.1 Transport at High Fields: Energy and Momentum Relaxation Times 152
4.4.2 Energy-Dependent Relaxation Time and Large B 153
4.4.3 Hall Factor 155
4.5 Delineation of Multiple Conduction Layer Mobilities 156
4.6 Carrier Transport in InN 158
4.7 Carrier Transport in AlN 159
4.8 Carrier Transport in Alloys 161
4.9 Two-Dimensional Transport in n-Type GaN 164
4.9.1 Scattering in 2D Systems 166
4.9.1.1 Electron Mobility in AlGaN/GaN 2D System 168
4.9.1.2 Numerical Two-Dimensional Electron Gas Mobility Calculations 170
4.9.1.3 Magnetotransport and Mobility Spectrum 173
Further Reading 174
5 The p–n Junction 177
5.1 Introduction 177
5.2 Band Alignment 177
5.3 Electrostatic Characteristics of p–n Heterojunctions 179
5.4 Current–Voltage Characteristics of p–n Junctions 185
5.4.1 Diode Current under Reverse Bias 186
5.4.1.1 Poole–Frenkel and Schottky Effects 187
5.4.1.2 Avalanching 188
5.4.2 Diffusion Current 189
5.4.2.1 Diffusion Current under Reverse Bias 190
5.4.2.2 Diffusion Current under Forward Bias 190
Further Reading 191
6 Optical Processes 193
6.1 Introduction 193
6.2 Einstein’s A and B Coefficients 194
6.3 Absorption and Emission 196
6.4 Band-to-Band Transitions and Efficiency 198
6.5 Optical Transitions in GaN 200
6.5.1 Excitonic Transitions in GaN 200
6.5.1.1 Strain Effects 203
6.5.1.2 Bound Excitons 204
6.6 Free-to-Bound Transitions 205
6.7 Donor–Acceptor Transitions 206
Further Reading 207
7 Light-Emitting Diodes and Lighting 209
7.1 Introduction 209
7.2 Current Conduction Mechanism in LED-Like Structures 211
7.3 Optical Output Power and Efficiency 214
7.3.1 Efficiency and Other LED Relevant Terms 215
7.3.2 Optical Power and External Efficiency 217
7.3.3 Internal Quantum Efficiency 218
7.3.3.1 Auger Recombination 219
7.3.3.2 SRH Recombination 220
7.3.3.3 Radiative Recombination 222
7.3.3.4 Continuity or Rate Equations as Pertained to Efficiency 223
7.3.3.5 Carrier Overflow (Spillover, Flyover, Leakage) 231
7.4 Effect of Surface Recombination 244
7.5 Effect of Threading Dislocation on LEDs 247
7.6 Current Crowding 247
7.7 Perception of Color 250
7.8 Chromaticity Coordinates and Color Temperature 251
7.9 LED Degradation 253
7.10 Packaging 255
7.11 Luminescence Conversion and White Light Generation 257
7.11.1 Color-Rendering Index 258
7.11.2 White Light from Multichip LEDs 259
7.11.3 Combining LEDs and Phosphor(s) 262
Further Reading 266
8 Semiconductor Lasers: Light Amplification by Stimulated Emission of Radiation 267
8.1 Introduction 267
8.2 A Primer to the Principles of Lasers 268
8.2.1 Waveguiding 270
8.2.2 Analytical Solution to the Waveguide Problem 273
8.2.2.1 TE Mode 274
8.2.2.2 TM Mode 276
8.2.3 Far-Field Pattern 280
8.3 Loss, Threshold, and Cavity Modes 281
8.4 Optical Gain 283
8.5 A Glossary for Semiconductor Lasers 286
8.5.1 Optical Gain in Bulk Layers: a Semiconductor Approach 289
8.5.1.1 Relating Absorption Rate to Absorption Coefficient 290
8.5.1.2 Relating Stimulated Emission Rate to Absorption Coefficient 290
8.5.1.3 Relating Spontaneous Emission Rate to Absorption Coefficient 290
8.5.2 Semiconductor Realm 291
8.5.3 Gain in Quantum Wells 299
8.5.3.1 Optical Gain 302
8.5.3.2 Measurement of Gain in Nitride Lasers 304
8.5.4 Gain Measurement via Optical Pumping 304
8.6 Threshold Current 306
8.7 Analysis of Injection Lasers with Simplifying Assumptions 307
8.7.1 Recombination Lifetime 309
8.7.2 Quantum Efficiency 311
8.8 GaN-Based LD Design and Performance 312
8.8.1 Gain Spectra of InGaN Injection Lasers 317
8.8.2 Mode Hopping 321
8.9 Thermal Resistance 322
8.10 Nonpolar and Semipolar Orientations 323
8.11 Vertical Cavity Surface-Emitting Lasers (VCSELs) 325
8.11.1 Microcavity Fundamentals 328
8.11.2 Polariton Lasers 333
8.12 Degradation 337
Appendix 8.A: Determination of the Photon Density and Photon Energy Density in a Cavity 343
Further Reading 348
9 Field Effect Transistors 349
9.1 Introduction 349
9.2 Operation Principles of Heterojunction Field Effect Transistors 350
9.2.1 Heterointerface Charge 350
9.2.2 Analytical Description of HFETs 358
9.3 GaN and InGaN Channel HFETs 364
9.4 Equivalent Circuit Models: De-embedding and Cutoff Frequency 366
9.4.1 Small-Signal Equivalent Circuit Modeling 367
9.4.2 Cutoff Frequency 370
9.5 HFET Amplifier Classification and Efficiency 373
9.6 Drain Voltage and Drain Breakdown Mechanisms 378
9.7 Field Plate for Spreading Electric Field for Increasing Breakdown Voltage 383
9.8 Anomalies in GaN MESFETs and AlGaN/GaN HFETs 384
9.8.1 Effect of the Traps in the Buffer Layer 386
9.8.2 Effect of Barrier States 392
9.8.3 Correlation between Current Collapse and Surface Charging 393
9.9 Electronic Noise 396
9.9.1 FET Equivalent Circuit with Noise 398
9.9.2 High-Frequency Noise in Conjunction with GaN FETs 402
9.10 Self-Heating and Phonon Effects 405
9.10.1 Heat Dissipation and Junction Temperature 406
9.10.2 Hot Phonon Effects 409
9.10.2.1 Phonon Decay Channels and Decay Time 411
9.10.2.2 Implications for FETs 416
9.10.2.3 Heat Removal in View of Hot Phonons 418
9.10.2.4 Tuning of the Hot Phonon Lifetime 421
9.11 HFET Degradation 427
9.11.1 Gated Structures: Reliability 434
9.11.2 Reliability Tests 438
9.12 HFETs for High-Power Switching 440
Appendix 9.A. Sheet Charge Calculation in AlGaN/GaN Structures with AlN Interface Layer (AlGaN/AlN/GaN) 444
Further Reading 446
Index 449
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