Preface ......................................................... v
About the Editors .............................................. xi
List of Contributors ......................................... xiii
CHAPTER 1
Nanocrystals and Quantum Dots: Some Physical Aspects
T.V. Torchynska
1 Introduction ................................................. 1
2 Quantum Size Effects ......................................... 2
2.1 Weak Confinement ........................................ 3
2.2 Strong Confinement ...................................... 5
3 Numerical Analyses of Quantum Size Effects ................... 5
4 Optical Transition Probabilities, Oscillator Strength and
Exciton Recombination Rate in Nanocrystals and Quantum
Dots ........................................................ 13
5 Oscillator Strength and Exciton Polariton Effects in
Nanocrystals ................................................ 18
6 Size Dispersion and Emission Spectra of Quantum Dots ........ 18
7 Photoluminescence of Oxidized Si Nanocrystals ............... 20
8 Hot Carrier Ballistic Transport and Luminescence
Excitation in Oxidized Si Nanocrystals ...................... 23
9 Surface Chemistry in Si Nanocrystalls and Quantum Dots ...... 25
10 Raman Scattering in Si Nanocrystals and Quantum Dots ........ 28
11 Electrical Transport in Nanocrystal and Quantum Dot
Structures .................................................. 33
12 Summary ..................................................... 37
References ..................................................... 38
CHAPTER 2.
Si and Ge Quantum Dot Structures
T.V. Torchynska
1 Introduction ................................................ 42
2 Emission of Si Quantum Dots Embedded in Silicon Oxide ....... 43
2.1 Si QDs in Silicon Oxide Prepared by RF-Magnetron
Co-Sputtering Method ................................... 43
2.2 Si QDs in Silicon Oxide Prepared by Thermal
Evaporation Method ..................................... 49
2.3 Si QDs in Silicon Oxide Prepared by Ion
Implantation ........................................... 50
2.4 Si QDs Prepared by Pulsed Laser Deposition ............. 52
2.5 Si QDs Prepared by Chemical Vapor Deposition ........... 53
2.6 Other Methods of Si QD Preparation ..................... 55
3 Emission of Ge Quantum Dots Embedded in the Silicon
Oxide ....................................................... 56
4 Emission of Amorphous and Crystalline Si Quantum Dots
Embedded in Silicon Nitride ................................. 58
5 Self-Assembled Si Quantum Dots on Insulated Substrates ...... 59
6 Self-Assembled Ge Quantum Dots on the Si Substrate .......... 61
6.1 Ge QDs Grown by Molecular Beam Epitaxy ................. 61
6.2 Controlled Processes of Ge/Si QD Nucleation ............ 62
7 New Technical Decisions for QD Emission Stimulation ......... 64
7.1 Si QD Emission Enhancement by Surface Plasmons ......... 64
7.2 Alkyl-Modified Silicon QDs ............................. 65
7.3 Emission of Rare Earth Atoms in Si Nanocrystal
Structures ............................................. 66
7.4 Nanophotonic Structures ................................ 68
8 Si QD Light Emitting Devices ................................ 70
9 Ge/Si QD Photodetectors ..................................... 72
10 Spintronics with QDs ........................................ 76
11 Summary ..................................................... 79
References ..................................................... 79
CHAPTER 3
Si Nanocrystals and Quantum Dots Embedded in Amorphous Si
Matrix
L. Khomenkova
1 Introduction ................................................ 85
2 Amorphous Silicon: Past and Future .......................... 87
3 Preparation Techniques for α-Si:H ........................... 88
3.1 Chemical Vapor Deposition and Its Modifications ........ 88
3.2 Hot-Wire Chemical Vapor Deposition ..................... 92
4 Structural Properties and Chemical Composition of nc-Si:H
Layers ...................................................... 93
4.1 Structural Properties of the nc-Si:H Films ............. 93
4.2 Chemical Composition of the Amorphous Layer ............ 99
5 Absorption Study in α-Si:H Films with NCs and QDs .......... 103
6 Light Emission Properties of α-Si:H Films with NCs and
QDs ........................................................ 103
7 Solar Cell Application of α-Si:H Films with NCs and QDs .... 108
References ................................................. 112
CHAPTER 4.
SiC Nanocrystal Structures
T.V. Torchynska, L.V. Shcherbyna
1 Introduction ............................................... 116
2 SiC Nanocrystal Applications and Perspectives .............. 116
2.1 Porous SiC ............................................ 117
2.2 SiC NCs in Organic Matrices ........................... 117
2.3 SiC NCs in Inorganic Dielectric or Semiconductor
Matrices .............................................. 118
2.4 SiC NCs in Metallic or Ceramic Matrices ............... 119
2.5 SiC Nanowires, Nanotubes and Nanoribbons .............. 119
3 Different Technologies for the Fabrication of SiC
Nanocrystal Structures ..................................... 120
3.1 Electrochemical Etching of the Bulk SiC ............... 120
3.2 SiC Nanocrystals Embedded in Inorganic Matrix ......... 121
3.3 SiC Nanocrystals and Quantum Dots Embedded in
Organic Matrix ........................................ 123
4 Emission Study in SiC NC Structures ........................ 124
4.1 Emission of SiC NCs in Porous SiC of Different
Polytypes ............................................. 124
4.2 Emission of 3C-SiC NCs in Amorphous SiC Matrix ........ 132
4.3 Emission of 3C-SiC NCs in Amorphous Si02 Matrix ....... 134
4.4 Emission of Colloidal 3C-SiC NCs in Different
Solvents .............................................. 134
4.5 Emission of SiCxNy NCs and SiCxNy/AlN
Superlattices ......................................... 136
5 Raman Scattering, FTIR and Ultra violet-Visible
Absorption Study in SiC NC Layers .......................... 136
5.1 Raman Scattering Spectra of Porous SiC Layers ......... 136
5.2 Raman Scattering Spectra of SiC NCs in Amorphous
SiC ................................................... 141
5.3 IR and Ultraviolet-Visible Absorption Study in SiC
NC Layers ............................................. 143
6 Conclusions ................................................ 144
References .................................................... 144
CHAPTER 5.
Electrical Properties of Semiconductor Nanocrystals and
Quantum Dots in Dielectric Matrix
I.V. Antonova
1 Introduction ............................................... 149
2 Room Temperature Quantum Size Effects in Thin Nanometer
Scale Oxide with Si (Ge) NCs and QDs ....................... 151
3 Resonant Tunneling and Charging Effects in Thick
Dielectric Layers with NCs and QDs ......................... 157
4 Single-Electron Charging Effect in the Individual Si QDs
Covered with Thin Dioxide .................................. 161
5 Collective Single Electron Effects in Double-Oxide
Barrier Structures with Si QDs ............................. 164
6 Carrier Tunneling in the Si-QDs/SiO2 Superlattices ......... 168
7 Photoconductivity of Si-QDs/SiO2 Layers .................... 171
8 Conductivity Mechanisms in Semiconductor NC or QD Arrays
Embedded in a Dielectric Matrix ............................ 173
9 Static Dielectric Constant of Silicon QDs Embedded in a
SiO2 Matrix ................................................ 176
10 Electron Transport in Si-QD Based Single Electron
Transistors (SETs) and Si NC Material Optimization
Towards the Room-Temperature Single-Electron Devices ....... 178
11 Summary .................................................... 183
References .................................................... 184
CHAPTER 6.
Optical Properties of Nanostructured Materials
Yu.V. Vorobiev, T.V. Torchynska
1 Introduction ............................................... 188
2 Nanostructured Materials for Optical Applications
(Scale, Geometry Physical and Technological Aspects) ....... 188
2.1 Sol-Gel Made Nanostructured Optical Materials ......... 189
2.2 Nanocrystals in Zeolite Cavities ...................... 192
2.3 Nanoporous Materials .................................. 193
2.4 Some Extraordinary Optical Properties of
Nanostructured Materials (Gigantic Non-Linearity
Enhanced Sensitivity to Polarization and
Wavelength) ........................................... 194
3 Peculiarities of Electromagnetic Waves Propagation in
Nanomaterials. Effective Parameters of the Nanocomposite
Media ...................................................... 196
3.1 Non-Periodic Nanostructured Materials ................. 196
3.2 Effects of Spatial Periodicity on Electromagnetic
Wave Propagation ...................................... 199
4 Theoretical Description of the Optical Electronic
Transitions in Nanostructures of Different Geometry ........ 203
4.1 Traditional Approach in the Quantum Mechanical
Treatment of the Optical Properties of
Nanostructures ........................................ 203
4.2 Effect of the Boundary Conditions on the Solution
of the Schrodinger Equation for Different
Structures ............................................ 205
4.3 "Mirror" Boundary Conditions in the Treatment of
the Nanostructures .................................... 207
5 Nanostructured Optical Components and Devices .............. 215
5.1 Nanostructured Filters, Waveguides, and
Antireflection Coatings ............................... 215
5.2 Nanostructured Materials in Solar Energy Conversion
Devices ............................................... 218
References .................................................... 221
CHAPTER 7.
Nanocrystal Memory Structures
Zs.J. Horváth, P. Basa
1 Introduction ............................................... 225
2 Non-Volatile MIS Memory Devices ............................ 226
2.1 Conventional Non-Volatile Memory Devices .............. 226
2.2 Problems and Possible Ways of Solution ................ 227
2.3 Charging Process ...................................... 229
2.4 Memory Structures with Semiconductor Nanocrystals ..... 231
3 Preparation of MIS Memory Structures with Si, Ge, or
SiGe Nanocrystals .......................................... 232
3.1 Ion Beam Synthesis of Nanocrystals .................... 232
3.2 Layer by Layer Growth ................................. 234
3.3 Direct CVD Growth of Nanocrystals ..................... 238
4 MIS Memory Structures with Silicon or Germanium
Nanocrystals ............................................... 239
4.1 Memory Structures with Silicon Nanocrystals ........... 239
4.2 Memory Structures with Germanium Nanocrystals ......... 241
5 Silicon Nitride-Based Nanocrystal Memory Structures ........ 243
6 Summary .................................................... 248
References .................................................... 248
CHAPTER 8
Technological Applications of Porous SiC
M. Mynbaeva, K. Mynbaev
1 Introduction ............................................... 253
2 Properties of Stoichiometric Porous Silicon Carbide ........ 254
3 Diffusion Doping of Porous SiC ............................. 257
4 Porous SiC in Substrate Technology ......................... 265
4.1 Homoepitaxy Over Stoichiometric Porous SiC ............ 265
4.2 Heteroepitaxy Over Stoichiometric Porous SiC .......... 268
5 Conclusions ................................................ 271
References .................................................... 271
Index ......................................................... 275
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