Properties of Impurity States in Superlattice Semiconductors

A NATO workshop on "The Properties of Impurity States in Semiconductor Superlattices" was held at the University of Essex, Colchester, United Kingdom, from September 7 to 11, 1987. Doped semiconductor superlattices not only provide a unique opportunity for studying low dimensional electronic behavior, they can also be custom-designed to exhibit many other fascinating el~ctronic properties. The possibility of using these materials for new and novel devices has further induced many astonishing advances, especially in recent years. The purpose of this workshop was to review both advances in the state of the art and recent results in various areas of semiconductor superlattice research, including: (i) growth and characterization techniques, (ii) deep and shallow im­ purity states, (iii) quantum well states, and (iv) two-dimensional conduction and other novel electronic properties. This volume consists of all the papers presented at the workshop. Chapters 1-6 are concerned with growth and characterization techniques for superlattice semiconductors. The question of a-layer is also discussed in this section. Chapters 7-15 contain a discussion of various aspects of the impurity states. Chapters 16- 22 are devoted to quantum well states. Finally, two-dimensional conduction and other electronic properties are described in chapters 23-26.

Inhalt

I. Growth Techniques and Characterizations of Superlattice Semiconductors.- 1 Doping in Two Dimensions: The ?-Layer.- 2 Optical Measurements of Acceptor Concentration Profiles at GaAs/GaAlAs Quantum Well Interfaces.- 3 Molecular Beam Epitaxy of Ga0.99Be0.01As for Very High Speed Heterojunction Bipolar Transistors.- 4 Progress Report on Molecular Beam Epitaxy of III-V Semiconductors - from Fibonacci to Monolayer Superlattices.- 5 Interface Characterization of GaInAs-InP Superlattices Grown by Low Pressure Metalorganic Chemical Vapor Deposition.- 6 Structural and Chemical Characterization of Semiconductor Interfaces by High Resolution Transmission Electron Microscopy.- II. Deep and Shallow Impurity States.- 7 Deep Level Behavior in Superlattice.- 8 Role of the Si Donors in Quantum and Ultraquantum Transport Phenomena in GaAs-GaAlAs Heterojunctions.- 9 Defects Characterization in GaAs-GaAlAs Superlattices.- 10 Studies of the DX Centre in Heavily Doped n+GaAs.- 11 Shallow and Deep Impurity Investigations: the Important Step Towards a Microwave Field-Effect Transistor Working at Cryogenic Temperatures.- 12 Electronic States in Heavily and Ordered Doped Superlattice Semiconductors.- 13 Properties of Impurity States in n-i-p-i Superlattice Structures.- 14 Deep Impurity Levels in Semiconductors, Semiconductor Alloys, and Superlattices.- 15 "Pinning" of Transition-Metal Impurity Levels.- III. Quantum Well States.- 16 Theory of Impurity States in Superlattice Semiconductors.- 17 Effective-Mass Theory of Electronic States in Heterostructures and Quantum Wells.- 18 Hot Electron Capture in GaAs MQW: NDR and Photo-Emission.- 19 In-Plane Electronic Excitations in GaAs/GaAlAs Modulation Doped Quantum Wells.- 20 Resonant Tunneling in Double Barrier Heterostructures.- 21 Extrinsic Photoluminescence in Unintentionally and Magnesium Doped GaInAs/GaAs Strained Quantum Wells.- 22 Magneto-Optics of Excitons in GaAs-(GaAl) As Quantum Wells.- IV. Two Dimensional and Other Electronic Properties.- 23 The Influence of Impurities on the Shubnikov-De Haas and Hall Resistance of Two-Dimensional Electron Gases in GaAs/AlxGa1-xAs Heterostructures Investigated by Back-Gating and Persistent Photoconductivity.- 24 Cyclotron Resonance of Polarons in Two Dimensions.- 25 Structure and Electronic Properties of Strained Si/Ge Semiconductor Superlattices.- 26 Theory of Raman Scattering from Plasmons Polaritons in GaAs/AlxGa1-xAs Superlattices.- In dex.