Semiconductor Nanostructures (eBook)

Dieter Bimberg (Herausgeber)

eBook Download: PDF

2008 | 2008
XXI, 357 Seiten
Springer Berlin (Verlag)
978-3-540-77899-8 (ISBN)

Infos

Reducing the size of a coherently grown semiconductor cluster in all three directions of space to a value below the de Broglie wavelength of a charge carrier leads to complete quantization of the energy levels, density of states, etc. Such 'quantum dots' are more similar to giant atoms in a dielectric cage than to classical solids or semiconductors showing a dispersion of energy as a function of wavevector. Their electronic and optical properties depend strongly on their size and shape, i.e. on their geometry. By designing the geometry by controlling the growth of QDs, absolutely novel possibilities for material design leading to novel devices are opened.

This multiauthor book written by world-wide recognized leaders of their particular fields and edited by the recipient of the Max-Born Award and Medal 2006 Professor Dieter Bimberg reports on the state of the art of the growing of quantum dots, the theory of self-organised growth, the theory of electronic and excitonic states, optical properties and transport in a variety of materials. It covers the subject from the early work beginning of the 1990s up to 2006. The topics addressed in the book are the focus of research in all leading semiconductor and optoelectronic device laboratories of the world.

Inhalt

Preface 6
References 8
Contents 10
List of Contributors 18
1 Thermodynamics and Kinetics of Quantum Dot Growth 23
1.1 Introduction 24
1.1.1 Length and Time Scales 25
1.1.2 Multiscale Approach to the Modeling of Nanostructures 26
1.2 Atomistic Aspects of Growth 27
1.2.1 Diffusion of Ga Atoms on GaAs(001) 27
1.2.2 Energetics of As2 Incorporation During Growth 27
1.2.3 Kinetic Monte Carlo Simulation of GaAs Homoepitaxy 28
1.2.4 Wetting Layer Evolution 31
1.3 Size and Shapes of Individual Quantum Dots 33
1.3.1 Hybrid Approach to Calculation of the Equilibrium Shape of Individual Quantum Dots 33
1.3.2 Role of High-Index Facets in the Shape of Quantum Dots 35
1.3.3 Shape Transition During Quantum Dot Growth 36
1.3.4 Constraint Equilibrium of Quantum Dots with aWetting Layer 37
1.4 Thermodynamics and Kinetics of Quantum Dot Ensembles 41
1.4.1 Equilibrium Volume of Strained Islands versus Ostwald Ripening 41
1.4.2 Crossover from Kinetically Controlled to Thermodynamically Controlled Growth of Quantum Dots 44
1.4.3 Tunable Metastability of Quantum Dot Arrays 47
1.4.4 Evolution Mechanisms in Dense Arrays of Elastically Interacting Quantum Dots 49
1.5 Quantum Dot Stacks 51
1.5.1 Transition between Vertically Correlated and Vertically Anticorrelated Quantum Dot Growth 51
1.5.2 Finite Size Effect: Abrupt Transitions between Correlated and Anticorrelated Growth 53
1.5.3 Reduction of a Size of a Critical Nucleus in the Second Quantum Dot Layer 54
1.6 Summary and Outlook 56
References 57
2 Control of Self-Organized In(Ga)As/GaAs Quantum Dot Growth 63
2.1 Introduction 63
2.2 Evolution and Strain Engineering of InGaAs/GaAs Quantum Dots 64
2.2.1 Evolution of InGaAs Dots 64
2.2.2 Engineering of Single and Stacked InGaAs QD Layers Single InGaAs QD Layers 68
2.3 Growth Control of Equally Shaped InAs/GaAs Quantum Dots 72
2.3.1 Formation of Self-Similar Dots with a Multimodal Size Distribution 73
2.3.2 Kinetic Description of Multimodal Dot-Ensemble Formation 76
2.4 Epitaxy of GaSb/GaAs Quantum Dots 78
2.4.1 Onset and Dynamics of GaSb/GaAs Quantum-Dot Formation 78
2.4.2 Structure of GaSb/GaAs Quantum Dots 80
2.5 Device Applications of InGaAs Quantum Dots 82
2.5.1 Edge-Emitting Lasers 82
2.5.2 Surface-Emitting Lasers 83
2.6 Conclusion 84
References 85
3 In-Situ Monitoring for Nano-Structure Growth in MOVPE 89
3.1 Introduction 89
3.2 Reflectance 91
3.3 Reflectance Anisotropy Spectroscopy (RAS) 93
3.3.1 RAS Spectra and Surface Reconstruction 94
3.3.2 Monolayer Oscillations 96
3.3.3 Monitoring of Carrier Concentration 101
3.4 Scanning Tunneling Microscopy (STM) 104
3.5 Conclusion 106
References 107
4 Bottom-up Approach to the Nanopatterning of Si(001) 109
4.1 Quantum Dot Growth on Semiconductor Templates 109
4.2 (2 × n) Reconstruction of Si(001) 110
4.3 Monte Carlo Simulations on the (2 × n) Formation 112
4.4 Scanning Tunneling Microscopy Results 114
4.5 Summary and Outlook 116
Acknowledgements 117
References 117
5 Structural Characterisation of Quantum Dots by X- Ray Diffraction and TEM 119
5.1 Introduction 119
5.2 Liquid Phase Epitaxy of SiGe/Si: A Model System for the Stranski - Krastanow Process 121
5.2.1 Dot Evolution in a Close-to-Equilibrium Regime 121
5.3 (In,Ga)As Quantum Dots on GaAs 125
5.3.1 Shape, Size, Strain and Composition Gradient in InGaAs QD Arrays 125
5.3.2 Chemical Composition of (In,Ga)As QDs Determined by TEM 129
5.3.3 Controlling 3D Ordering in (In,Ga)As QD Arrays through GaAs Surface Orientation 131
5.4 Ga(Sb,As) Quantum Dots on GaAs 135
5.4.1 Structural Characterisation of Ga(Sb,As) QDs by High-Resolution TEM Imaging 139
5.4.2 Chemical Characterisation of Ga(Sb,As) QDs by HAADF STEM Imaging 140
References 141
6 The Atomic Structure of Quantum Dots 145
6.1 Introduction 145
6.2 Experimental Details 146
6.3 STM Studies of InAs Quantum Dots on the Growth Surface 146
6.4 XSTM Studies of Buried Nanostructures 149
6.4.1 InAs Quantum Dots 149
6.4.2 InGaAs Quantum Dots 153
6.4.3 GaSb Quantum Dots 156
6.5 Conclusion 157
Acknowledgements 157
References 158
7 Theory of Excitons in InGaAs/GaAs Quantum Dots 161
7.1 Introduction 161
7.2 Interrelation of QD-Structure, Strain and Piezoelectricity, and Coulomb Interaction 162
7.2.1 The Binding Energies of the Few Particle Complexes 162
7.3 Method of Calculation 165
7.3.1 Calculation of Strain 166
7.3.2 Piezoelectricity and the Reduction of Lateral Symmetry 167
7.3.3 Single Particle States 169
7.3.4 Many-Particle States 170
7.3.5 The Configuration Interaction Model 170
7.3.6 Interband Spectra 172
7.4 The Investigated Structures: Variation of Size, Shape and Composition 172
7.5 The Impact of QD Size 173
7.5.1 The Role of the Piezoelectric Field 175
7.6 The Aspect Ratio 177
7.6.1 Vertical Aspect Ratio Different Types of Charge Separation Effects 177
7.6.2 Lateral Aspect Ratio 179
7.7 Different Composition Profiles 179
7.7.1 Inverted Cone-Like Composition Profile 179
7.7.2 Annealed QDs 181
7.7.3 InGaAs QDs with Uniform Composition 181
7.8 Correlation vs. QD Size, Shape and Particle Type 181
7.9 Conclusions 184
References 185
8 Phonons in Quantum Dots and Their Role in Exciton Dephasing 187
8.1 Introduction 187
8.2 Structural Properties of Semiconductor Nanostructures 188
8.3 Theory of Acoustic Phonons in Quantum Dots 188
8.3.1 Continuum Elasticity Model of Phonons 189
8.3.2 Phonons in Quantum Dots 192
8.4 Exciton-Acoustic Phonon Coupling in Quantum Dots 193
8.5 Dephasing of the Exciton Polarization in Quantum Dots 195
8.5.1 Single Exciton Level: Independent Boson Model 196
8.5.2 Multilevel System: Real and Virtual Phonon-Assisted Transitions 198
8.5.3 Application to Coupled Quantum Dots 204
8.6 Summary 206
References 207
9 Theory of the Optical Response of Single and Coupled Semiconductor Quantum Dots 211
9.1 Introduction 211
9.2 Theory 212
9.2.1 Quantum Dot Model 212
9.2.2 Hamiltonian 213
9.2.3 Mathematical Formalisms 215
9.3 Single Quantum Dot Response 218
9.3.1 Linear Absorption Spectra and Quantum Optics 218
9.3.2 Semiclassical Nonlinear Dynamics 221
9.4 Two Coupled Quantum Dots 223
9.4.1 Absorption Spectra 224
9.4.2 Excitation Transfer 224
9.4.3 Rabi Oscillations 225
9.4.4 Pump-Probe/Differential Transmission Spectra 226
9.5 Multiple Quantum Dots 227
9.5.1 Four-Wave-Mixing: Photon Echo in Quantum Dot Ensembles 227
9.5.2 Absorption of Multiple Coupled Quantum Dots 227
9.5.3 Energy Transfer of Multiple Coupled Quantum Dots 228
9.6 Conclusion 228
Acknowledgements 229
References 229
10 Theory of Nonlinear Transport for Ensembles of Quantum Dots 233
10.1 Introduction 233
10.2 Coulomb Interaction within a Quantum Dot Layer 233
10.3 Transport in Quantum Dot Stacks 235
10.4 Current Fluctuations and Shot Noise 236
10.5 Full Counting Statistics and Decoherence in Coupled Quantum Dots 238
10.6 Conclusion 240
References 241
11 Quantum Dots for Memories 243
11.1 Introduction 243
11.2 Semiconductor Memories 244
11.2.1 Dynamic Random Access Memory (DRAM) 244
11.2.2 Nonvolatile Semiconductor Memories (Flash) 245
11.2.3 A QD-based Memory Cell 246
11.3 Charge Carrier Storage in Quantum Dots 248
11.3.1 Experimental Technique 248
11.3.2 Carrier Storage in InGaAs/GaAs Quantum Dots 250
11.3.3 Hole Storage in GaSb/GaAs Quantum Dots 251
11.3.4 InGaAs/GaAs Quantum Dots with Additional AlGaAs Barrier 252
11.4 Conclusion and Outlook 255
Acknowledgements 256
References 257
12 Visible-Bandgap II-VI Quantum Dot Heterostructures 259
12.1 Introduction 259
12.2 Epitaxial Growth 260
12.3 Few-Particles States and Their Fine Structure 263
12.3.1 Excitons and Biexcitons 263
12.3.2 Trions in Charged Quantum Dots 265
12.4 Coherent Control of the ExcitonÒBiexciton System 267
12.5 Spin Relaxation of Excitons, Holes, and Electrons 269
12.5.1 Exciton Quantum Coherence 269
12.5.2 Hole Spin Lifetime 270
12.5.3 Spin Dynamics of the Resident Electron 271
12.6 Diluted Magnetic Quantum Dots 273
Acknowledgements 275
References 275
13 Narrow-Gap Nanostructures in Strong Magnetic Fields 277
13.1 Introduction 277
13.2 Materials: HgSe/HgSe:Fe 278
13.3 Fabrication of HgSe/HgSe:Fe Nanostructures 278
13.3.1 QuantumWells 279
13.3.2 Roof-Ridge QuantumWires 280
13.3.3 Quantum Dots 281
13.4 Electronic Characterization of the HgSe/HgSe:Fe Nano- Structures in Strong Magnetic Fields 284
13.4.1 High-Field Magneto Transport 284
13.4.2 Infrared Magneto-Resonance Spectroscopy 285
13.5 Summary 289
References 289
14 Optical Properties of III-V Quantum Dots 291
14.1 Introduction 291
14.2 Confined States and Many-Particle Effects 292
14.2.1 Renormalization 292
14.2.2 Phonon Interaction 296
14.2.3 Electronic Tuning by Strain Engineering 298
14.2.4 Multimodal InAs/GaAs Quantum Dots 300
14.3 Single InAs/GaAs Quantum Dots 303
14.3.1 Spectral Diffusion 303
14.3.2 Size-Dependent Anisotropic Exchange Interaction 304
14.3.3 Binding Energies of Excitonic Complexes 307
14.3.4 Data Storage Using Confined Trions 308
14.3.5 Electronic Tuning by Annealing 309
14.4 Optical Properties of InGaN/GaN Quantum Dots 310
14.4.1 Time-Resolved Studies on Quantum Dot Ensembles 311
14.4.2 Single-Dot Spectroscopy 314
14.5 Summary 318
References 320
15 Ultrafast Coherent Spectroscopy of Single Semiconductor Quantum Dots 323
15.1 Introduction 323
15.2 Interface Quantum Dots 325
15.3 Coherent Spectroscopy of Interface Quantum Dots: Experimental Technique 327
15.4 Coherent Control in Single Interface Quantum Dots 330
15.4.1 Ultrafast Optical Nonlinearities of Single Interface Quantum Dots 330
15.4.2 Rabi Oscillations in a Quantum Dot 334
15.4.3 Optical Stark Effect: Ultrafast Control of Single Exciton Polarizations 337
15.5 Coupling Two Quantum Dots via the Dipole-Dipole Interaction 341
15.6 Summary and Conclusions 345
Acknowledgment 346
References 347
16 Single-Photon Generation from Single Quantum Dots 351
16.1 Introduction 351
16.2 Single Quantum Dots as Single-Photon Emitters 353
16.2.1 Photon Statistics of Single-Photon Emitters 353
16.2.2 Micro-Photoluminescence 354
16.2.3 Single Photons from InP Quantum Dots 355
16.3 Multiphoton Emission from Single Quantum Dots 356
16.4 Realization of the Ultimate Limit of a Light Emitting Diode 361
16.5 Applications in Quantum Information Processing 365
16.5.1 Quantum Key Distribution 365
16.5.2 Quantum Computing 366
16.6 Outlook 368
References 369
Index 373

Produkt-Details

• Erscheint lt. Verlag: 3.6.2008
• Reihe/Serie: NanoScience and Technology
• Zusatzinfo: XXI, 357 p.
• Verlagsort: Berlin
• Sprache: englisch
• Themenwelt: Naturwissenschaften ► Physik / Astronomie
• Themenwelt: Technik ► Elektrotechnik / Energietechnik
• Themenwelt: Technik ► Maschinenbau
• Schlagworte: Cluster • diffraction • Dispersion • electronic properties • Exciton • Material • nanostructure • nanostructures • optical properties • quantum dot • Quantum dots • Self-organised growth • semiconductor • spectroscopy • Transport • Vakuuminjektionsverfahren
• ISBN-10: 3-540-77899-3 / 3540778993
• ISBN-13: 978-3-540-77899-8 / 9783540778998