Wide Bandgap Light Emitting Materials and Devices

Nitrides with Nonpolar Surfaces......Page 4
Contents......Page 8
Preface......Page 18
List of Contributors......Page 22
Color Plates......Page 26
Introduction......Page 44
1.1 Introduction......Page 46
1.2 Historical Survey of Nonpolar Nitride Growth Achievements......Page 48
1.3.1 Morphology......Page 54
1.3.2 Microstructure......Page 56
1.3.3 Strain......Page 57
1.3.4 Optical Properties......Page 61
1.3.5 Optical Phonons......Page 64
1.3.6 Electrical Properties......Page 65
1.4 Nonpolar and Semipolar Nitride-based Devices Today......Page 66
1.5 Prospects in the Development of Nonpolar Nitrides and Devices......Page 67
Acknowledgments......Page 68
References......Page 69
Part I Growth......Page 74
2.1 Introduction......Page 76
2.2 Planar a-plane GaN Growth......Page 78
2.3 Lateral Epitaxial Overgrowth of a-plane GaN Films......Page 82
2.4 Planar m-plane GaN Heteroepitaxy......Page 87
2.5 Lateral Epitaxial Overgrowth of m-plane GaN......Page 91
References......Page 93
3.1 Introduction......Page 96
3.2.1 Seed Crystals......Page 97
3.2.2 Bulk Crystallization of GaN by HVPE on Small Seeds......Page 98
3.2.3 HVPE of GaN on Platelet-shaped Seeds......Page 99
3.2.4 HVPE of GaN on Needle-shaped Seeds......Page 103
3.3.1 GaN/AlGaN Quantum Structures Grown by PA Molecular Beam Epitaxy......Page 105
3.3.2 Optical Properties of Nonpolar Structures Grown on GaN Quasi-Wafers Sliced from Bulk GaN Crystals......Page 106
References......Page 113
4.1 Introduction......Page 116
4.2 The Crystalline Structure of AlN and SiC......Page 118
4.4 AlN/6H-SiC (1120)......Page 121
4.5 AlN/4H-SiC (1120)......Page 125
4.6 Reducing Structural Defect Densities in 4H-AlN......Page 129
4.7 AlN/4H-SiC (1100)......Page 135
4.8 Properties of 4H-AlN......Page 137
4.9 Nonpolar AlGaN and AlGaN/AlN Heterostructures......Page 138
4.10 Conclusion......Page 139
References......Page 140
5.1 Introduction......Page 144
5.2 Growth and Properties of a-plane GaN on r-plane Sapphire......Page 146
5.3 Growth and Properties of m-plane GaN on m-plane SiC......Page 149
5.5 Reduction of Dislocation Density and Stacking-fault Density by Sidewall Seeded Epitaxial Lateral Overgrowth......Page 151
5.6.1 n-type GaN......Page 155
5.6.2 p-type GaN......Page 156
5.7.1 GaInN/GaNMQWs......Page 157
5.7.2 AlGaN/GaN Single Heterostructure......Page 158
5.8 Characterization of Visible LEDs on Nonpolar GaN......Page 159
5.9 Summary......Page 160
Further Reading......Page 161
6.1 Introduction......Page 162
6.2.1.1 Properties and Merits......Page 163
6.2.1.3 Orientation Relationship andMicrostructure......Page 164
6.2.2.1 Properties and Merits......Page 165
6.2.2.3 Orientation Relationship and Microstructure......Page 166
6.3.1 Substrate Preparation and Impact of Polarity......Page 167
6.3.2.1 Growth......Page 169
6.3.2.4 Impact of Nucleation Conditions on Phase Purity......Page 170
6.3.3.1 Roughness versus T(N)......Page 172
6.3.3.2 TEM......Page 173
6.4.1.1 Relation between Ga Coverage and Surface Reconstructions......Page 174
6.4.2 Ga Adsorption/Desorption Kinetics......Page 176
6.5.1 In Incorporation and Surface Segregation......Page 182
6.5.1.2 HRXRD......Page 183
6.5.1.3 SIMS......Page 185
6.5.2.1 cw-PL......Page 186
6.5.2.2 Anomalous Temperature-dependent PLWidth......Page 187
6.5.2.3 PL Transition Energy as a Function of Well Thickness......Page 188
6.5.2.4 Recombination Dynamics......Page 189
6.6 Conclusion and Outlook......Page 192
References......Page 193
Part II Properties......Page 196
7.1 Introduction......Page 198
7.2 Experimental Details......Page 200
7.3.1 Unstrained GaN with Polar and Nonpolar Orientations......Page 202
7.3.2 Strain Dependence for Polar Orientations of GaN......Page 205
7.3.3 Strain Dependence for Nonpolar Orientations of GaN......Page 206
7.4.1 Strained GaN Films with Different Nonpolar Orientations......Page 208
7.4.2 Polarized Photoluminescence Spectroscopy of M-plane GaN Films......Page 212
7.4.3 Polarized Photoluminescence Spectroscopy of M-plane (In,Ga)N/GaN Multiple Quantum Wells......Page 215
7.5.1 Static and Dynamic Polarization Filtering......Page 218
7.5.2 Polarization-sensitive Photodetectors......Page 219
7.5.3 Very Narrow-band Photodetectors......Page 221
7.5.4 Polarized Light Emitters......Page 223
7.6 Summary......Page 224
References......Page 225
8.1 Introduction......Page 228
8.2 Luminescence in GaN Layers Grown along the [0001] Direction (c-Plane Layers)......Page 229
8.3.1 a-Plane GaN Layers Grown on r-Plane Sapphire......Page 232
8.3.2 a-Plane GaN Layers Grown on a-Plane SiC......Page 246
8.4.1 m-Plane GaN Layers Grown on γ-LiAlO(2)......Page 247
8.4.2 m-Plane GaN Layers Grown on m-Plane SiC......Page 250
8.5 Luminescence in GaN Layers Grown along Semipolar Directions......Page 252
8.6 Luminescence in GaN with Nonpolar Surfaces Sliced from Boules Grown along the c Axis......Page 254
8.7 Summary......Page 255
Acknowledgments......Page 256
References......Page 257
9.1 Introduction......Page 262
9.2.1 Structure of Wurtzite GaN......Page 264
9.2.2 Phonons in Wurtzite GaN......Page 265
9.2.3 Lattice Deformation and Strain......Page 266
9.2.3.1 Biaxial Isotropic Strain in GaN......Page 267
9.2.3.2 Anisotropic Strain in GaN......Page 268
9.2.5 Raman Scattering Spectroscopy......Page 269
9.2.6 Infrared Spectroscopic Ellipsometry......Page 272
9.2.6.1 Standard Ellipsometry......Page 273
9.2.6.3 Ellipsometry Data Analysis......Page 274
9.3.1 Assessment of Anisotropic Strain Components......Page 277
9.3.2 Anisotropic Lattice Distortion......Page 278
9.4.1 Strain-free Frequencies of GaN Phonons......Page 281
9.4.2.1 Infrared Dielectric Tensor......Page 282
9.4.3 Phonon Splitting......Page 285
9.4.4.1 Anisotropic Phonon Deformation Potentials......Page 288
9.4.4.2 A(1)(TO) and E(1)(LO) Phonon Deformation Potentials......Page 289
9.4.5 Quantum Dots......Page 292
9.5 Summary and Outlook......Page 293
Acknowledgments......Page 294
References......Page 295
10.1 Introduction......Page 298
10.2.1 Growth Procedure......Page 299
10.2.2 Defect Characterization......Page 300
10.2.3 Why Planar Defects are Formed in the Layers Grown on Nonpolar Surfaces......Page 308
10.3.1 Growth of Thick Layers......Page 312
10.3.2 Lateral Overgrowth......Page 313
10.3.3 Pendeo-epitaxial Layers......Page 316
10.4 Application of Pendeo-epitaxy for the Layers Grown on Nonpolar Substrates......Page 317
10.5 Application of Lateral Overgrowth for a-plane GaN Layers Grown on the r plane of Al(2)O(3)......Page 321
10.6 Summary......Page 326
References......Page 327
11.1 Introduction......Page 330
11.1.1 Conventions......Page 331
11.1.2 Lattice Mismatch......Page 332
11.2.1 Point Defects and Impurities......Page 334
11.2.1.1 Point Defects......Page 335
11.2.1.2 Impurities......Page 336
11.2.2 Dislocations......Page 337
11.2.2.1 Dislocation Types in a-GaN......Page 340
11.2.2.2 Dislocation Formation Energy......Page 341
11.2.2.3 Impact of Anisotropy......Page 342
11.2.3 Planar Defects......Page 344
11.2.3.1 Basal Plane Stacking Faults......Page 345
11.2.3.2 Analysis of Basal Plane Stacking Faults......Page 346
11.2.3.3 Prismatic and Pyramidal Stacking Faults......Page 347
11.2.4.1 Nanopipes......Page 350
11.2.5 Surface Defects......Page 351
11.3.1 Epitaxial Relationship......Page 352
11.3.2 Interfacial Structure......Page 353
11.3.2.1 HRTEM along the [1100](GaN) Zone Axis......Page 354
11.3.2.2 HRTEM along the [0001](GaN) Zone Axis......Page 355
11.3.3 Model of Interfacial Structure......Page 356
11.4 Summary......Page 358
References......Page 359
Further Reading......Page 361
Part III Nonpolar Heterostructures and Devices......Page 362
12.1 Introduction......Page 364
12.2.1.1 Experiment......Page 365
12.2.1.2 Results......Page 366
12.2.2.1 Experiment......Page 373
12.2.2.2 Results......Page 374
12.3.1 Introduction and Background......Page 379
12.3.2.1 Experiment......Page 380
12.3.2.2 Results......Page 381
12.3.2.3 Wavelength Shift in Nonpolar a-Plane LEDs......Page 385
12.3.3.1 Experiments......Page 386
12.3.3.2 Results......Page 387
12.3.3.3 DC and Pulsed Performance of m-plane Packaged LED Lamps......Page 390
12.3.3.4 Transmission Through Free-standing m-plane Substrate......Page 392
12.3.4 Comparison of Power Performance of a-plane and m-plane LEDs......Page 393
12.5 Recent Nonpolar Optical Device Results Overview......Page 395
12.6 Conclusions......Page 396
References......Page 397
13.1 Introduction......Page 400
13.2.1 Substrates and Growth Conditions......Page 401
13.2.2 Anisotropy of MBE-grown AlN a-plane Surface......Page 402
13.3.1 Impact of Growth Parameters: Nominal GaN Quantity......Page 403
13.3.2 Morphology of a-plane GaN QDs......Page 405
13.3.3 Strain State of a-plane GaN QDs......Page 408
13.4.1 Optical Spectroscopy on Ensembles of QDs......Page 414
13.4.2 Single QD Spectroscopy......Page 417
13.4.3 Radiative Decay Time Analysis......Page 423
Acknowledgments......Page 425
References......Page 426
14.1 Introduction......Page 428
14.2 Semipolar {1122} Planes......Page 430
14.3.1 Fabrication and Fundamental Properties of Microfacet QWs......Page 431
14.3.2 Emission Properties of {1122} Microfacet QWs......Page 435
14.3.3.1 Multicolor Emission Based on Intra-facet Variations of the In Composition......Page 438
14.3.3.2 Multicolor Emission based on Inter-facet Variations of the QW Structures......Page 441
14.4 Planar QWs and LEDs......Page 443
14.4.1 MOVPE Growth and Fundamental Properties of GaN and In-GaN/GaN QWs......Page 444
14.4.2 Semipolar LEDs......Page 448
Acknowledgments......Page 452
References......Page 453
Index......Page 456