Device Physics of Narrow Gap Semiconductors (eBook)

Device Physics of NarrowGap Semiconductors 2
Foreword 5
Preface 7
Contents 9
1 Introduction 14
2 Impurities and Defects 18
2.1 Conductivity and Ionization Energies of Impurities and Native Point Defects 18
2.1.1 Defects 18
2.1.2 Chemical Analysis of Impurity Defects and their Conductivity Modifications 23
2.1.3 Theoretical Estimation Method for Impurity Levels 27
2.1.4 Doping Behavior 40
2.1.5 Experimental Methods 47
2.1.5.1 High-Frequency and Low-Frequency Capacitance Measurement Principles 47
2.1.5.2 Deep Level Transient Spectroscopy 50
2.1.5.3 Photoluminescence Spectroscopy 50
2.1.5.4 Photothermal Ionization Spectrum Principles 51
2.1.5.5 Quantum Capacitance Spectrum Technology 52
2.1.5.6 Positron Annihilation Spectra for MCT 53
2.1.5.7 Optical Hall Effect Measurements 56
2.2 Shallow Impurities 59
2.2.1 Introduction 59
2.2.2 Shallow Donor Impurities 62
2.2.3 Shallow Acceptor Impurities 67
2.3 Deep Levels 74
2.3.1 Deep Level Transient Spectroscopy of HgCdTe 74
2.3.2 Deep Level Admittance Spectroscopy of HgCdTe 82
2.3.3 Frequency Swept Conductance Spectroscopy 88
2.4 Resonant Defect States 92
2.4.1 Capacitance Spectroscopy of Resonant Defect States 93
2.4.2 Theoretical Model 96
2.4.3 Resonant States of Cation Substitutional Impurities 98
2.5 Photoluminescence Spectroscopy of Impurities and Defects 100
2.5.1 Introduction 100
2.5.2 Theoretical Background for Photoluminescence 102
2.5.3 Infrared PL from an Sb-Doped HgCdTe 116
2.5.4 Infrared PL in As-doped HgCdTe Epilayers 121
2.5.5 Behavior of Fe as an Impurity in HgCdTe 126
References 132
3 Recombination 138
3.1 Recombination Mechanisms and Life Times 138
3.1.1 Recombination Mechanisms 138
3.1.2 The Continuity Equation and Lifetimes 140
3.1.3 The Principle Recombination Mechanisms and the Resulting Lifetimes of HgCdTe 141
3.2 Auger Recombination 147
3.2.1 The Types of Auger Recombination 147
3.2.2 Auger Lifetime 148
3.3 Shockley–Read Recombination 157
3.3.1 Single-Level Recombination Center 157
3.3.2 General Lifetime Analysis 161
3.4 Radiative Recombination 165
3.4.1 Radiative Recombination Processes in Semiconductors 165
3.4.2 Lifetime of Radiative Recombination 166
3.4.3 Radiative Recombination in p-Type HgCdTe Materials 169
3.5 Lifetime Measurements of Minority Carriers 171
3.5.1 The Optical Modulation of Infrared Absorption Method 171
3.5.2 The Investigation of Minority Carriers Lifetimes in Semiconductors by Microwave Reflection 182
3.5.3 The Application of Scanning Photoluminescence for Lifetime Uniformity Measurements 185
3.5.4 Experimental Investigation of Minority Carrier Lifetimes in Undoped and p-Type HgCdTe 189
3.6 Surface Recombination 196
3.6.1 The Effect of Surface Recombination 196
3.6.2 Surface Recombination Rate 201
3.6.3 The Effect of Fixed Surface Charge on the Performance of HgCdTe Photoconductive Detectors 203
Appendix 3.A 209
Appendix 3.A 209
Appendix 3.B Sandiford Paper 210
Appendix 3.B Sandiford Paper 210
References 212
4 Two-Dimensional Surface Electron Gas 215
4.1 MIS Structure 215
4.1.1 The Classical Theory of an MIS Device 215
4.1.2 Quantum Effects 221
4.2 A Theory That Models Subband Structures 223
4.2.1 Introduction 223
4.2.2 A Self-Consistent Calculational Model 226
4.3 Experimental Research on Subband Structures 234
4.3.1 Quantum Capacitance Subband Structure Spectrum Model 234
4.3.2 Quantum Capacitance Spectrum in a Nonquantum Limit 241
4.3.3 Experimental Research of Two-Dimensional Gases on the HgCdTe Surface 245
4.3.4 Experimental Research of a Two-DimensionalElectron Gas on an InSb Surface 250
4.4 Dispersion Relations and Landau Levels 254
4.4.1 Expressions for Dispersion Relationsand Landau Levels 254
4.4.2 Mixing of the Wave Functions and the Effective g Factor 259
4.5 Surface Accumulation Layer 264
4.5.1 Theoretical Model of n-HgCdTe SurfaceAccumulation Layer 265
4.5.2 Theoretical Calculations for an n-HgCdTe Surface Accumulation Layer 267
4.5.3 Experimental Results for n-HgCdTe SurfaceAccumulation Layers 269
4.5.4 Results of an SdH Measurement 270
4.6 Surfaces and Interfaces 275
4.6.1 The Influence of Surface States on the Performance of HgCdTe Photoconductive Detectors 275
4.6.2 The Influence of the Surfaceon the Magneto-Resistance of HgCdTe Photoconductive Detectors 281
4.6.3 The Influence of Surfaceson the Magneto-Resistance Oscillations of HgCdTe Samples 286
4.6.4 The Influence of the Surface on the Correlation Between Resistivity and Temperature for an HgCdTe Photoconductive Detector 288
References 290
5 Superlattice and Quantum Well 294
5.1 Semiconductor Low-Dimensional Structures 294
5.1.1 Band Dispersion Relation 294
5.1.2 Density of States 299
5.1.3 Optical Transitions and Selection Rules 300
5.2 Band Structure Theory of Low-Dimensional Structures 303
5.2.1 Band Structure Theory of Bulk Semiconductors 303
5.2.2 Envelope Function Theory for Heterostructures 307
5.2.2.1 The Luttinger Model 310
5.2.2.2 The Kane Model 311
5.2.2.3 The Kane Model in an External Magnetic Field 313
5.2.3 Specific Features of Type III Heterostructures 314
5.2.3.1 Three Different Band Structure Regimes 314
5.2.3.2 Interface States 315
5.2.3.3 Consequences of an Inverted Band Structure 316
5.3 Magnetotransport Theory of Two-Dimensional Systems 317
5.3.1 Two-Dimensional Electron Gas 317
5.3.2 Classical Transport Theory: The Drude Model 319
5.3.3 Landau Levels in a Perpendicular Magnetic Field 320
5.3.4 The Broadening of the Landau Levels 323
5.3.5 Shubnikov-de Haas Oscillations of a 2DEG 324
5.3.6 Quantum Hall Effect 326
5.4 Experimental Results on HgTe/HgCdTe Superlattices and QWs 332
5.4.1 Optical Transitions of HgTe/HgCdTe Superlattices and Quantum Wells 332
5.4.2 Typical SdH Oscillations and the Quantum Hall Effect 336
5.4.3 Rashba Spin–Orbit Interaction in n-TypeHgTe Quantum Wells 339
References 345
6 Devices Physics 351
6.1 HgCdTe Photoconductive Detector 351
6.1.1 Brief Introduction to Photoconductive Device Theory 351
6.1.2 Device Performance Characterization Parameters 355
6.1.3 Noise 358
6.1.3.1 Thermal Noise 359
6.1.3.2 Generation–Recombination Noise 360
6.1.3.3 1/f Noise 360
6.1.3.4 Amplifier Noise 363
6.1.3.5 Total Noise 363
6.1.3.6 Background Noise and Background Limited Detectivity 365
6.1.4 The Impact of Carrier Drift and Diffusion on Photoconductive Devices 366
6.2 Photovoltaic Infrared Detectors 370
6.2.1 Introduction to Photovoltaic Devices 370
6.2.2 Current-Voltage Characteristicfor p–n Junction Photodiodes 373
6.2.3 The Photocurrent in a p–n Junction 387
6.2.4 Noise Mechanisms in Photovoltaic Infrared Detectors 391
6.2.5 Responsivity, Noise Equivalent Power and Detectivity 394
6.3 Metal-Insulator-Semiconductor Infrared Detectors 399
6.3.1 MIS Infrared Detector Principles 399
6.3.2 The Dark Current in MIS Devices 404
6.4 Low-Dimensional Infrared Detectors 410
6.4.1 Introduction 410
6.4.2 Basic Principles of QW Infrared Photodetectors 413
6.4.3 Bound-to-Continuum State Transition QW Infrared Detector 418
6.4.4 Miniband Superlattice QWlPs 425
6.4.5 Multiwavelength QW Infrared Detectors 427
6.4.6 Quantum-Dots Infrared Detectors 429
6.5 Low-Dimensional Semiconductor Infrared Lasers 437
6.5.1 Introduction 437
6.5.2 Basics of Intersubband Cascade Lasers 439
6.5.3 Basic Structures of Intersubband Cascade Lasers 443
6.5.4 Antimony Based Semiconductor Mid-Infrared Lasers 456
6.5.5 Interband Cascade Lasers 459
6.5.6 Applications of Quantum Cascade Lasers 465
6.6 Single-Photon Infrared Detectors 466
6.6.1 Introduction 466
6.6.2 Fundamentals of an APD 468
6.6.3 The Basic Structure of an APD 474
6.6.3.1 Guard-Ring APD 477
6.6.3.2 Inverted APD, Also Known as a Buried APD 477
6.6.3.3 Beveled-Mesa APD 477
6.6.3.4 Reach-Through APD 477
6.6.4 Fundamentals of a Single-Photon Avalanche Diode (SPAD) 478
6.6.4.1 SPAD Operating Conditions and Performance 479
6.6.4.2 Two Basic Quenching Circuits 481
6.6.5 Examples of Single-Photon Infrared Detectors 484
6.6.5.1 Si, and Ge Based SPADs 484
6.6.5.2 III–V Semiconductor SPADs 487
6.6.5.3 Far-Infrared Single-Electron-Transistor SPADs 488
References 490
Appendix 499
I Various Quantities for Hg1-xCdxTe 499
1 Energy band gap Eg (eV) from (A.1) (Appendix Part II) 499
2 Wavelengths corresponding to energy gaps Eg (m) 502
3 Peak-wavelengths of the photo-conductive response peak and the cut-off wavelengths co (m) for samples with a thickness d = 10m (from (A.2) to (A.3) in Appendix Part II) 504
4 Intrinsic carrier concentrations ni (cm-3) (from (A.4) in Appendix Part II) 507
5 Electron effective masses at the bottom of conduction band m0/m0 (from (A.12) in Appendix Part II) 508
II Some Formulas 510
Index 512