Optical Properties of Semiconductor

Low-dimensional semiconductor structures, often referred to as nanocrystals or quantum dots, exhibit fascinating behavior and have a multitude of potential applications, especially in the field of communications. This book examines in detail the optical properties of these structures, giving full coverage of theoretical and experimental results, and discusses their technological applications. The author begins by setting out the basic physics of electron states in crystals (adopting a 'cluster-to-crystal' approach), and goes on to discuss the growth of nanocrystals, absorption and emission of light by nanocrystals, optical nonlinearities, interface effects, and photonic crystals. He illustrates the physical principles with references to actual devices such as novel light-emitters and optical switches.

Preface

xi

1 Electron states in crystal

1

(26)

1.1 A few problems from elementary quantum mechanics

1

(15)

1.1.1 Particle in a potential well

1

(4)

1.1.2 Particle in a spherically symmetric potential

5

(3)

1.1.3 Electron in Coulomb potential

8

(3)

1.1.4 Particle in a periodic potential

11

(5)

1.2 Schroedinger equation for an electron in a crystal

16

(3)

1.3 Concept of quasiparticles: electron, hole, and exciton

19

(4)

1.4 Low-dimensional structures: quantum wells, quantum wires, and quantum dots

23

(4)

2 Electron states in an ideal nanocrystal

27

(28)

2.1 From crystal to cluster: effective mass approximation

27

(15)

2.1.1 Weak confinement regime

28

(2)

2.1.2 Strong confinement limit

30

(5)

2.1.3 Surface polarization and finite barrier effects

35

(3)

2.1.4 Hole energy levels and optical transitions in real semiconductors

38

(1)

2.1.5 Size-dependent oscillator strength

39

(3)

2.2 From cluster to crystal: quantum-chemical approaches

42

(9)

2.2.1 Semiconductor nanocrystals as large molecules

42

(2)

2.2.2 General characteristics of quantum-chemical methods

44

(3)

2.2.3 Semiempirical techniques

47

(1)

2.2.4 Quantum-chemical calculations for semiconductor clusters

47

(4)

2.3 Size regimes in quasi-zero-dimensional structures

51

(4)

3 Growth of nanocrystals

55

(17)

3.1 Nanocrystals in inorganic matrices

55

(8)

3.1.1 Glass matrices: diffusion-controlled growth

55

(6)

3.1.2 Nanocrystals in porous glasses

61

(1)

3.1.3 Semiconductor nanocrystals in ionic crystals

61

(1)

3.1.4 Nanocrystals in zeolites

62

(1)

3.1.5 Composite semiconductor-glass films

62

(1)

3.1.6 Other techniques

63

(1)

3.2 Inorganics in organics: semiconductor nanocrystals in organic solutions and in polymers

63

(2)

3.3 Nanocrystals on crystal substrates: self-organized growth

65

(1)

3.4 Synopsis of nanocrystals fabricated by various techniques

66

(6)

4 General properties of spectrally inhomogeneous media

72

(12)

4.1 Population-induced optical nonlinearity and spectral hole-burning

72

(6)

4.2 Persistent spectral hole-burning in heterogeneous media

78

(1)

4.3 Luminescent properties

79

(2)

4.4 Single molecule spectroscopy

81

(3)

5 Absorption and emission of light by semiconductor nanocrystals

84

(69)

5.1 Size-dependent absorption spectra. Inhomogeneous broadening and homogeneous linewidths

84

(14)

5.1.1 Experimental evidence for quantum-size effects in real nanocrystals

84

(8)

5.1.2 Selective absorption spectroscopy: spectral hole-burning

92

(1)

5.1.3 Selective emission spectroscopy

93

(2)

5.1.4 Other manifestations of inhomogeneous broadening

95

(1)

5.1.5 Correlation of optical properties with the precipitation stages for nanocrystals in a glass matrix

96

(2)

5.2 Valence band mixing

98

(4)

5.3 Exciton-phonon interactions

102

(15)

5.3.1 Lattice oscillations

102

(3)

5.3.2 Concept of phonons

105

(2)

5.3.3 Vibrational modes in small particles

107

(1)

5.3.4 "Phonon bottleneck"; selective population of the higher states

108

(3)

5.3.5 Line-shapes and linewidths

111

(1)

5.3.6 Lifetime broadening

112

(1)

5.3.7 Dephasing due to exciton-phonon interactions

113

(4)

5.4 Size-dependent radiative decay of excitons

117

(16)

5.4.1 Superradiant decay of excitons in larger crystallites

117

(3)

5.4.2 Radiative transitions in nanocrystals of indirect-gap materials

120

(6)

5.4.3 Polarization of luminescence

126

(2)

5.4.4 Exchange interaction and Stokes shift

128

(5)

5.5 Single dot spectroscopy

133

(4)

5.6 Quantum dot in a microcavity

137

(4)

5.7 Recombination mechanisms

141

(4)

5.8 Electric field effect on exciton absorption

145

(4)

5.9 Electroluminescence

149

(2)

5.10 Doped nanocrystals

151

(2)

6 Resonant optical nonlinearities and related many-body effects

153

(26)

6.1 Specific features of many-body effects in nanocrystals

153

(2)

6.2 Exciton-exciton interactions in large quantum dots

155

(6)

6.3 Genuine absorption saturation in small quantum dots

161

(7)

6.4 Biexcitons in small quantum dots

168

(4)

6.5 Optical gain and lasing

172

(3)

6.6 Two-photon absorption

175

(1)

6.7 Optical bistability and pulsations

176

(3)

7 Interface effects

179

(24)

7.1 Laser annealing, photodarkening, and photodegradation

179

(4)

7.2 Interface effects on the properties of copper halide nanocrystals

183

(3)

7.3 Persistent spectral hole-burning

186

(3)

7.4 Photochemical hole-burning

189

(6)

7.5 Classification of the spectral hole-burning phenomena in quantum dot ensembles

195

(3)

7.6 Tunneling and migration of carriers and their influence on luminescence decay

198

(5)

8 Spatially organized ensembles of nanocrystals

203

(10)

8.1 Superlattices of nanocrystals: quantum dot solids

203

(3)

8.2 Photonic crystals

206

(7)

References

213

(28)

Index

241

What is included with this book?

The New copy of this book will include any supplemental materials advertised. Please check the title of the book to determine if it should include any access cards, study guides, lab manuals, CDs, etc.

The Used, Rental and eBook copies of this book are not guaranteed to include any supplemental materials. Typically, only the book itself is included. This is true even if the title states it includes any access cards, study guides, lab manuals, CDs, etc.

FREE SHIPPING

Amazon no longer offers textbook rentals. We do!

Optical Properties of Semiconductor Nanocrystals

Summary

Table of Contents

Supplemental Materials