Silicon Nanocrystals: Fundamentals, Synthesis and Applications

Silicon Nanocrystals: Fundamentals, Synthesis and Applications......Page 2
Contents......Page 8
List of Contributors......Page 20
1 Introduction......Page 26
References......Page 29
2.1 Introduction......Page 30
2.2 Ab Initio Calculation for Small Nanocrystals......Page 32
2.2.1 Hydrogenated Silicon Nanocrystals......Page 34
2.2.2 Oxidized Silicon Nanocrystals......Page 36
2.2.3.1 Single-Doped Silicon Nanocrystals......Page 39
2.2.3.2 Codoped Silicon Nanocrystals......Page 40
2.2.4 Silicon Nanocrystals Embedded in a SiO2 Matrix......Page 43
2.3 Pseudopotential Calculations for Large Nanocrystals......Page 47
2.3.1 Effective Optical Gap......Page 49
2.3.2 Radiative Lifetime......Page 50
2.3.3 Linear Optical Absorption......Page 51
2.3.3.1 Interband Absorption......Page 53
2.3.3.2 Intraband Absorption......Page 54
2.3.3.3 Excited State Absorption......Page 55
2.3.4 Third-Order Nonlinear Optical Properties......Page 57
2.3.5 Quantum-Confined Stark Effect in Si Nanocrystals......Page 60
References......Page 63
3.1 Introduction......Page 68
3.2.1 Fundamental Properties......Page 70
3.2.3 Resonant Quenching of PL Band Due to Energy Transfer......Page 73
3.2.4 PL Quantum Efficiency of Intrinsic Si Nanocrystals......Page 76
3.3.1 Preparation of Impurity-Doped Si Nanocrystals......Page 78
3.3.2 PL from B-Doped Si Nanocrystals......Page 79
3.3.4 Electron Spin Resonance Studies of Shallow Impurity-Doped Si Nanocrystals......Page 80
3.3.5 Location of Dopant Atoms......Page 82
3.4 P and B Codoped Si Nanocrystals......Page 83
3.4.1 PL Properties of P and B Codoped Si Nanocrystals......Page 84
3.4.2 PL Lifetime of P and B Codoped Si Nanocrystals......Page 87
3.5 Summary......Page 88
References......Page 89
4.1 Introduction......Page 94
4.2.1 Basic Concepts Associated with Transport and Quantum Dots......Page 96
4.2.2 Previous Studies of Transport in Systems of Si......Page 100
4.3 Experimental Details......Page 103
4.4 Experimental Results and Their Interpretation......Page 106
4.4.1 The Low-x Regime......Page 109
4.4.2 The Low-x to Intermediate-x Transition Regime......Page 111
4.4.3 The Intermediate-x Regime......Page 112
4.4.4 The Percolation Threshold Regime......Page 114
4.4.5 The High-x Regime......Page 117
4.5 Discussion and Overview......Page 121
References......Page 126
5.1 Introduction......Page 130
5.2.1 Kinetic Theory: Thermal Properties and Heat Flow......Page 132
5.2.2 Lattice Thermal Conductivity......Page 133
5.2.3 Electronic Thermal Conductivity......Page 137
5.3 Measurements of Thermal Conductivity in Nanostructures......Page 139
5.3.1 The 3ω Method......Page 140
5.3.2 In-Plane Thermal Conductivity Measurements......Page 142
5.3.3 Pump-Probe and Other Optical Measurements......Page 144
5.3.4 Raman Scattering and Thermal Conductivity......Page 145
5.4.1 Two- and One-Dimensional Si Nanostructures: Si-on-Insulator and Si Nanowires......Page 147
5.4.2 Epitaxially Grown Si/SiGe Nanostructures: Superlattices and Cluster Multilayers......Page 150
5.4.3 Electrochemically Etched Si (Porous Si)......Page 156
5.4.4 Nanocrystalline Si/SiO2 Multilayers......Page 159
5.5 Conclusions......Page 168
References......Page 170
6.1 Introduction......Page 180
6.3 In Situ Surface Chemistry Tailoring......Page 181
6.5 Solution-Based Postsynthetic Modification......Page 183
6.6 Hydrosilylation......Page 186
6.7 Substitutional Approaches to Surface Functionalization......Page 192
6.8 Building on an Oxide Layer......Page 193
6.9 How Many Surface Groups are on the Particle?......Page 194
6.11 Future Outlook and the Role of Surface Chemistry......Page 196
References......Page 197
7.1 Introduction......Page 198
7.2 Late Stellar Evolution......Page 199
7.3 Interstellar Medium and Dust Evolution......Page 202
7.4 Early Stellar Evolution and Planetary System Formation......Page 206
7.5 Dust in the Solar System......Page 208
7.6 Extended Red Emission and Si Nanoparticles as a Potential Carrier......Page 209
7.7 Formation of Si Nanoparticles under Nonequilibrium Conditions......Page 214
7.8 Conclusions......Page 216
References......Page 217
8.1 Introduction......Page 220
8.2 Size Control of Si Nanocrystals by the SiO/SiO2 Superlattice Approach......Page 221
8.3 Crystallization Behavior......Page 225
8.4 Defects and their Signatures in ESR......Page 231
8.5 Optical Properties......Page 240
8.6 Applications of Si NCs and Concluding Remarks......Page 244
References......Page 245
9.1 Introduction......Page 248
9.2 Ion Implantation......Page 249
9.3.1 Ion Range Distributions......Page 251
9.3.2 Multiple Energy Implants......Page 254
9.3.3 High-Fluence Effects......Page 255
9.4 Size Distribution......Page 256
9.4.1.1 Nucleation and Growth of Nanocrystals......Page 257
9.4.2 Spinodal Decomposition......Page 260
9.4.4 Hot Implants......Page 261
9.5 Irradiation Effects......Page 262
9.5.1 Radiation Damage......Page 263
9.5.2 Ion-Beam Mixing......Page 264
9.5.3 Irradiation-Induced Precipitation......Page 265
9.6.2 Choice of Substrate Material......Page 266
9.6.4 Waveguides and All-Optical Amplifiers......Page 267
9.6.7 Photonic Crystal Structures......Page 268
References......Page 269
10.1 Introduction......Page 272
10.2 Synthesis, Structure, and Thermal Evolution of SiOx Films......Page 274
10.3 A Deeper Insight into the Thermal Evolution of SiOx Films......Page 278
10.4 Room-Temperature PL Properties of Si-ncs......Page 283
10.5 Excitation and De-Excitation Properties of Si-ncs......Page 285
10.6 Correlation between Structural and Optical Properties of Si-ncs......Page 289
10.7 Er-Doped Si Nanoclusters......Page 292
10.8 Summary......Page 296
References......Page 297
11.1 Introduction......Page 300
11.3 Results......Page 301
11.3.1 Single Layer......Page 302
11.3.2 Composite Layer......Page 304
11.3.3 Multilayer......Page 308
11.3.3.1 Effect of the Sublayer Thickness......Page 309
11.3.3.2 Effect of the Annealing Temperature......Page 312
References......Page 317
12 Si and SiC Nanocrystals by Pyrolysis of Sol–Gel-Derived Precursors......Page 322
12.1 The Sol–Gel and PDC Processes......Page 323
12.2 Si nc/SiO2 Glasses and Films......Page 325
12.3 (Si-nc + SiC-nc)/SiO2 Glasses and Films......Page 327
12.4 Optical properties of Multicomponent Si-C-O-N Ceramics......Page 330
References......Page 331
13.1 Introduction......Page 334
13.2.1 Nanoparticle Nucleation in Nonthermal Plasmas......Page 335
13.2.2 Nanoparticle Charging......Page 337
13.2.3 Nanoparticle Heating in Plasmas......Page 339
13.3 Silicon Nanocrystal Synthesis in Nonthermal Plasmas......Page 342
13.3.1 Experimental Apparatus......Page 343
13.3.2.2 Particle Size Distribution......Page 345
13.3.2.3 Nanocrystal Surface Conditions......Page 347
13.3.2.4 Optical Properties of Surface-Oxidized Silicon Nanocrystals......Page 351
13.4.1 Liquid-Phase Functionalization......Page 352
13.4.2 Liquid-Phase Hydrosilylation Procedure......Page 353
13.4.3 Plasma Grafting of Silicon Nanocrystals......Page 355
13.5 Optical Properties of Plasma-Synthesized and Surface-Functionalized Silicon Nanocrystals......Page 362
13.6 Summary and Conclusions......Page 366
References......Page 367
14.1 Introduction......Page 374
14.2.1.1 Conditions Leading to Porous Si Formation......Page 375
14.2.1.2.1 Electrochemical Etching of Si......Page 376
14.2.1.3 Effect of Anodization Conditions......Page 377
14.2.1.4 Local Formation and Patterning of Porous Si......Page 379
14.2.2.1 Galvanic Etching......Page 380
14.2.2.2 Electroless Etching......Page 381
14.2.3 Drying of Porous Si......Page 382
14.3.1 As-Formed Porous Si......Page 383
14.3.3 Stabilization of the Porous Si Surface......Page 384
14.4.1.1 Electrical Conduction and Transport......Page 385
14.4.1.3 Sensing Based on Change of Conductivity......Page 386
14.4.1.5.1 Ballistic Electron Emission......Page 387
14.4.1.5.3 Ballistic Electron Emission in Gas and Liquids......Page 389
14.4.2.1 Refractive Index and Absorption Coefficient......Page 390
14.4.2.2 Passive Photonic Structures......Page 391
14.4.2.2.2 Manipulation of Light Using Index Modulation......Page 392
14.4.2.3.2 Optical Gas/Liquid/Biomolecule Sensing and Drug Delivery......Page 396
14.4.3.1.1 Characteristics of the S-Band......Page 397
14.4.3.1.2 Photoluminescence Efficiency......Page 399
14.4.3.2 Energy Transfer, Sensing, and Imaging Using Porous Si Photoluminescence......Page 401
14.4.3.3 Electroluminescence......Page 402
14.4.4.1.2 Acoustic Band Crystals......Page 404
14.4.4.2 Thermoacoustic Emission......Page 405
References......Page 406
15.1.1 Challenges in Silicon Flash Memory Technology......Page 420
15.1.2 Emerging nc-Si Flash Memory Devices......Page 422
15.1.3 Outline......Page 423
15.2.1 nc-Si Memory Structures......Page 424
15.2.2.1 Storing Charges with Multiple nc-Si Dots......Page 426
15.2.2.2 Storing Charges with Single nc-Si Dot......Page 427
15.3.1 Fabrication of nc-Si Dots......Page 429
15.3.1.2 Bottom–Up Methodology......Page 430
15.3.2 Memory Cell Fabrications......Page 432
15.4 Characteristics of nc-Si Flash Memory......Page 435
15.4.1 Memory Operations......Page 436
15.4.2 Interfacial States......Page 439
15.4.3 Retention Characteristics with Electron Charge, Storage, and Discharge......Page 442
15.4.4 Characteristics Improvements of the nc-Si Flash Memory......Page 445
15.4.5 Operation Speed and Device Reliability......Page 456
15.5 Comparisons of Emerging Nonvolatile Memory Devices......Page 459
15.5.1 Silicon Nanocrystals Flash Memory and Other Types of Nonvolatile Memory......Page 460
15.5.2 Silicon Nanocrystals Memory Devices and Other Quantum Dot Memory Devices......Page 461
15.6 Concluding Remarks and Prospects......Page 462
References......Page 463
16.1 Introduction to Silicon Nanophotonics......Page 470
16.2.1 General Properties......Page 472
16.2.2 Si-nc Slot Waveguides......Page 475
16.2.3 Ring Resonators Based on Slot Waveguides......Page 476
16.3 Nanosilicon Cavity-Based Devices......Page 478
16.3.1 Slow-Wave Devices......Page 479
16.3.2 Si-nc Active Microdisks......Page 481
16.4 Si-nc-Based Visible Optical Amplifiers......Page 482
16.5 Nanosilicon-Based Infrared Optical Amplifiers......Page 486
16.6.1 Si-nc-Based LED......Page 490
16.6.2 Si-nc-Based Solar Cells......Page 494
16.7 Nanosilicon Nonlinear Optical Properties and Devices......Page 498
References......Page 502
17 Lighting Applications of Rare Earth-Doped Silicon Oxides......Page 512
17.1 Solid-State Lighting: A Basic Introduction......Page 513
17.2 Luminescence of Rare Earth-Doped Silicon-Based Materials......Page 514
17.3 White Light Emitting Si-Based Device Structures......Page 526
17.4 Fabrication of RE-Doped Silicon-Based Layers for SSL......Page 528
17.5 Conclusions and Future Outlook......Page 529
References......Page 530
18.1 Introduction......Page 532
18.2.1 Synthesis and Optical Properties of Si Nanoparticles......Page 534
18.2.2.1 Alkali–Acid Etching of Si NPs......Page 537
18.2.2.2 Surface Modification of Si NPs by Silanization......Page 538
18.2.2.3 Surface Modification of Si NPs via Hydrosilylation......Page 539
18.3 Biointeraction of Si-Based Nanoparticles......Page 541
18.3.1 Cell Viability......Page 542
18.3.2 Genotoxicity......Page 543
18.3.4 Effect of NP Size......Page 544
18.3.5 In Vitro and In Vivo Comparative Studies......Page 548
18.4 Applications of Si NPs in Biomedicine......Page 549
18.5 Si Nanoparticle-Based Sensors......Page 555
18.6 Conclusions......Page 556
References......Page 557
19.1 Introduction......Page 562
19.2.1 Production of Porous Silicon......Page 563
19.2.2 Stabilization of Porous Silicon Surface......Page 567
19.3.1 Infiltration of the Pores with Different Oxidizers......Page 570
19.3.2 Mechanical Mixing of Porous Silicon Powder with Oxidizers......Page 577
19.4 Conclusions......Page 578
References......Page 579
20.1.1 Limits of Single-Bandgap Cells......Page 580
20.1.2 Solar Cells with Multiple Energy Levels......Page 581
20.2.1 Solid-Phase Formation of Si Nanocrystals......Page 582
20.2.2 Quantum Confinement in Si QD Nanostructures......Page 584
20.2.3 Carrier Tunneling Transport in Si QD Superlattices......Page 587
20.3 The "All-Si" Tandem Cell: Si Nanostructure Tandem Cells......Page 588
20.3.1.1 Si Quantum Dots in a Silicon Nitride Matrix......Page 589
20.3.2 Doping of Si QD Arrays......Page 591
20.3.2.1 Phosphorus Doping of Si Nanostructures......Page 592
20.3.2.2 Boron Doping of Si Nanostructures......Page 593
20.3.2.3 Doping Mechanisms......Page 594
20.3.3.1 Si QDs in SiO2 Solar Cell......Page 595
20.3.3.2 Si QDs in SiC Solar Cell......Page 596
20.4 Intermediate Level Cells: Intermediate Band and Impurity Photovoltaic cell......Page 597
20.5 Multiple Carrier Excitation Using Si QDs......Page 598
20.6 Hot Carrier Cells......Page 599
20.6.1 Photoluminescence of Si QD ESCs......Page 600
20.6.2 Negative Differential Resistance in Si QD ESCs......Page 602
20.7 Conclusions......Page 603
References......Page 604
21.1 Introduction......Page 608
21.2.2 Transmission Electron Microscopy......Page 609
21.2.3 Electron Energy Loss Spectroscopy......Page 610
21.2.4 Energy Filtered Transmission Electron Microscopy (EFTEM)......Page 612
21.2.5 Si Nanocluster Imaging by Atomic Force Microscopy......Page 613
21.3.1 Raman Spectroscopy......Page 615
21.3.3 Size Estimation of the Nanocrystals......Page 616
21.3.4 Stress Estimation on Nanocrystals......Page 618
21.3.6 X-Ray Diffraction Analysis of Nanocrystals......Page 619
21.3.7 Method of Integral Breadths......Page 622
21.3.9 X-Ray Photoelectron Spectroscopy......Page 623
21.4.1 Fourier Transform Infrared Spectroscopy......Page 627
21.5.1 Photoluminescence Spectroscopy......Page 631
References......Page 634
Index......Page 638