Electronic States and Optical Transitions in Semiconductor Heterostructures

Heterostructures, made by growing several ultrathin layers of different materials (down to a few atoms in thickness) on top of a silicon or other substrates, have remarkable properties not shared by bulk materials. One can, for example, confine the motions of electrons to a single layer, making it possible to investigate effectively two- dimensional systems. One can also build materials with large-scale periodicities by alternating layers of different compositions, thereby modulating the optical and electronic properties of the resulting structure. This graduate-level textbook provides the theoretical basis and the relevant experimental knowledge underlying our present understanding of the electrical and optical properties of

1 Electronic Structure of Abrupt Heterojunctions.- 1.1 Band Diagrams of Heterostructures.- 1.2 k · p Model for Heterojunctions.- 1.3 Shallow Electronic States at Heterojunctions.- 1.4 Field-Induced Interface States.- 1.5 Intervalley Mixing at Heterojunctions.- 1.6 Numerical Methods for the Description of Heterostructures 27 Bibliography Notes.- 2 Electrons in Low-Dimensional Structures.- 2.1 Formation of Confined Electronic States.- 2.2 Electronic States in Quantum Wells, Wires, and Dots.- 2.3 Self-Consistent Electronic States in Quantum Wells.- 2.4 More Complex Quantum Wells.- 2.5 Mixing of Hole States in Heterostructures.- 2.6 Multiband k · p Approximation.- 2.7 Electronic States in the Presence of Strain.- Bibliography Notes.- 3 Tunneling in Heterostructures.- 3.1 Tunneling Transmission.- 3.2 Tunnel-Coupled Levels.- 3.3 Superlattices.- 3.4 Superlattices Formed by States of Different Origin.- Bibliography Notes.- 4 Impurity States and Excitons in Heterostructures.- 4.1 Electron Localization on Imperfections.- 4.2 Impurity States in Quantum Wells.- 4.3 Quantum Well Excitons.- 4.4 Excitons in Other Heterostructures.- Bibliography Notes.- 5 Interband Optical Transitions in Heterostructures.- 5.1 Absorption of Light by a 2D Layer.- 5.2 Polarization Dependence of the Interband Transitions.- 5.3 Interband Absorption Spectra in Heterostructures.- 5.4 Excitonic Absorption.- 5.5 Electrooptics of Heterostructures.- 5.6 Modulation Spectroscopy of Heterostructures.- Bibliography Notes.- 6 Radiative Processes in Heterostructures.- 6.1 Theory of Luminescence in 2D Systems.- 6.2 Spectral and Polarization Dependencies of Luminescence.- 6.3 Luminescence from Complex Heterostructures.- 6.4 Radiative Recombination.- Bibliography Notes.- 7 Scattering of Light on Low-Dimensional Electrons.- 7.1 Scattering Cross-Section.- 7.2 Raman Spectroscopy of Intersubband Excitations.- 7.3 Scattering on Collective Electronic Excitations.- Bibliography Notes.- 8 Intersubband Optical Transitions.- 8.1 Resonant Transitions and Excitation into the Continuum.- 8.2 Intersubband Transitions for In-Plane Electric Field.- 8.3 Depolarization Shift and Coulomb Renormalization.- 8.4 Submillimeter Intersubband Transitions.- 8.5 Radiative Intraband Transitions in Heterostructures.- Bibliography Notes.- 9 Nonlinear Optics of Heterostructures.- 9.1 Nonlinear Response.- 9.2 Nonlinear Susceptibilities.- 9.3 Photoelectric Phenomena.- 9.4 Nonlinearities Induced by Electron-Hole Pairs.- Bibliography Notes.- 10 Ultrafast Processes in Heterostructures.- 10.1 Ultrafast Optical Excitation.- 10.2 Carrier Relaxation Processes.- 10.3 Coherent Optics of Heterostructures.- 10.4 Ultrafast Charge Dynamics in Heterostructures.- Bibliography Notes.- 11 Heterostructure-Based Optoelectronic Devices.- 11.1 Heterostructure Lasers.- 11.2 Electrooptic Modulators.- 11.3 Photodetectors.- 11.4 Intersubband Optoelectronic Devices.- 11.5 Optical Characterization of Heterostructures.- Bibliography Notes.- A k · p Method for Bulk Semiconductors.- A.I Nondegenerate Band.- A.2 Two-Band Model.- A.3 Luttinger Model.- A.4 Kane Model.- A.5 Effects of External Fields.- A.6 Effects of Deformation.- Bibliography Notes.- B Electromagnetic Waves in Layered Media.- B.I Modes in a Layered Medium.- B.2 Second Quantization of the Field.- Bibliography Notes.- C Kinetic Equations for Electrons and Photons.- C.I Kinetic Equations Approach.- C.2 Wigner Function for Photons.- C.3 Electron Response.- C.4 Conductivity and Generation Rate.- Bibliography Notes.- D Coulomb Effects in Heterostructures.- D.I Mean Field Treatment of Coulomb Effects.- D.2 Matrix Elements for 3D, 2D, and ID States.- D.3 Intraband Density Matrix Equations.- D.4 Semiconductor Bloch Equations.- D.5 Beyond the Mean-Field Approximation.- Bibliography Notes.- References.