Physics and Applications of Quantum Wells and Superlattices

Physics and Applications of Quantum Wells and Superlattices

NATO ASI Series Advanced Science Institutes Series A series presenting the results of activities sponsored by the NA TO Science Committee, which aims at the dissemination of advanced scientific and technological knowledge, with a view to strengthening links between scientific communities. The series is published by an international board of publishers in conjunction with the NATO Scientific Affairs Division A B C D E F G H Life Sciences Physics Mathematical and Physical Sciences Behavioral and Social Sciences Applied Sciences Computer and Systems Sciences Ecological Sciences Cell Biology Plenum Publishing Corporation New York and London Kluwer Academic Publishers Dordrecht, Boston, and London Springer-Verlag Berlin, Heidelberg, New York, London, PariS, and Tokyo Recent Volumes in this Series Volume 165-Relativistic Channeling edited by Richard A. Carrigan, Jr., and James A. Ellison Volame 166-lncommensurate Crystals, Liquid Crystals, and Quasi-Crystals edited by J. F. Scott and N. A. Clark Volume 167-Time-Dependent Effects in Disordered Materials edited by Roger Pynn and Tormod Riste Volume 168-0rganic and Inorganic Low-Dimensional Crystalline Materials edited by Pierre Delhaes and Marc Drillon Volume 169-Atomic Physics with Positrons edited by J. W. Humbertson and E. A. G. Armour Volume 170-Physics and Applications of Quantum Wells and Superlattices edited by E. E. Mendez and K. von Klitzing Volume 171-Atomic and Molecular Processes with Short Intense Laser Pulses edited by Andre D. Bandrauk Volume 172-Chemical Physics of Intercalation edited by A. P. Legrand and S. Flandrois Series B: Physics

Physics and Applications of Quantum Wells and Superlattices Edited by E. E. Mendez IBM Thomas J. Watson Research Center Yorktown Heights, New York and K. von Klitzing Max Planck Institute for Solid State Research Stuttgart, Federal Republic of Germany Plenum Press New York and London Published in cooperation with NATO Scientific Affairs Division

Proceedings of a NATO Advanced Study Institute on Physics and Applications of Quantum Wells and Superlattices, held April 21-May 1, 1987 in Erice, Sicily, Italy Library of Congress Cataloging in Publication Data NATO Advanced Study Institute on Physics and Applications of Quantum Wells and Superlattices (1987: Erice, Sicily) Physics and applications of quantum wells and superlattices. (NATO ASI Series. Series B, Physics; vol. 170) "Proceedings of a NATO Advanced Study Institute on Physics and Applications of Quantum Wells and Superlattices, held April 21-May 1, 1987, in Erice, Sicily, Italy"-T.p. verso. "Published in cooperation with NATO Scientific Affairs Division." Includes bibliographical references and index. 1. Superlattices as materials-congresses. 2. Quantum wells-congresses. 3. Semiconductors-Congresses. 4. Molecular beam epitaxy-congresses. I. Mendez, E. E. II. Klitzing, K. von. III. North Atlantic Treaty Organization. Scientific Affairs Division. IV. Title. V. Series. QC611.8.S86N38 1987 530.4'1 88-2510 ISBN-13: 978-1-4684-5480-2 e-isbn-13: 978-1-4684-5478-9 001: 10.1007/978-1-4684-5478-9 1987 Plenum Press, New York Softcover reprint of the hardcover 1 st edition 1987 A Division of Plenum Publishing Corporation 233 Spring Street, New York, N.Y. 10013 All rights reserved No part of this book may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, microfilming, recording, or otherwise, without written permission from the Publisher

PREFACE This book contains the lectures delivered at the NATO Advanced Study Institute on "Physics and Applications of Quantum Wells and Superlattices", held in Erice, Italy, on April 21-May 1, 1987. This course was the fourth one of the International School of Solid-State Device Research, which is under the auspices of the Ettore Majorana Center for Scientific Culture. In the last ten years, we have seen an enormous increase in research in the field of Semiconductor Heterostructures, as evidenced by the large percentage of papers presented in recent international conferences on semiconductor physics. Undoubtfully, this expansion has been made possible by dramatic advances in materials preparation, mostly by molecular beam epitaxy and organometallic chemical vapor deposition. The emphasis on epitaxial growth that was prevalent at the beginning of the decade (thus, the second course of the School, held in 1983, was devoted to Molecular Beam Epitaxy and Heterostructures) has given way to a strong interest in new physical phenomena and new material structures, and to practical applications that are already emerging from them. The purpose of this Institute has been to address in an integrated form the basic physical concepts of semiconductor wells and superlattices, and their relation to technological applications based in these novel structures. Although the goal has not been so much to review the most recent results in the field, as to present the fundamental ideas and how they can be implemented in new devices, we hope that the reader will find these lectures also valuable as a resource of current research activity in the field. After an introductory review of the evolution of semiconductor superlattices since their inception in 1969, the book is divided in four parts. First, the electronic band structure of superlattices is discussed in Chapter 2, followed by three chapters describing the use of molecular beam epitaxy to the growth of heterostructures based v

on III-V, II-VI, and IV compounds, respectively. The second part focuses on their transport properties, both parallel and perpendicular to the interface direction. The drastic influence of a strong magnetic field on them -the best example of which is the quantum Hall effect- occupies a significant fraction of this section. Part three is devoted to optical properties. The characteristics of radiative recombination are studied in Chapter 12, which also considers the principles of quantum-well lasers. The inelastic scattering of light by heterostructures is discussed in the next chapter, followed by a study of far-infrared absorption, and of the effect of a magnetic field on the optical properties. Finally, part four presents applications of quantum wells and superlattices based on either their electrical or optical characteristics, including a discussion of devices that might integrate them both. We are thankful to A. Gabriele, who provided at the Ettore Majorana Center the right atmosphere for the celebration of a scientific retreat. We thank also L. Esaki, director of the School, for his support during the different phases of the Institute, and to L. L. Chang and K. Ploog, directors of a previous edition of the School, for their advice in the organization of the Course. Finally, we are grateful to the NATO Scientific Affairs Division, to the Italian Ministries of Education and Scientific and Technological Research, to the Sicilian Regional Government, to the U.S. Army European Research Office, to the European and American Physical Societies, and to International Business Machines, whose sponsorhip has made possible this International School.

CONTENTS INTRODUCTION A Perspective in Quantum-Structure Development.......... 1 L. Esaki BASIC PROPERTIES AND MATERIALS GROWTH Electronic States in Semiconductor Heterostructures...... 21 G. Bastard Molecular Beam Epitaxy of Artificially Layered III-V Semiconductors on an Atomic Scale.. _....... _.. 43 K. Ploog Molecular Beam Epitaxial Growth and Properties of Hgbased Microstructures _...... 71 J. P. Faurie Strained Layer Superlattices.... _. _..... _... 101 E. Kasper ELECTRICAL PROPERTIES Electrical Transport in Microstructures............ 133 F. Stern Physics of Resonant Tunneling in Semiconductors..... 159 E. E. Mendez Thermodynamic and Magneto-Optic Investigations of the Landaulevel Density of States for 2D Electrons. _... 189 E. Gornik High Field Magnetotransport: Lectures I and II: Analysis of Shubnikov-de Haas Oscillations and Parallel Field Magnetotransport.... _...... 217 R. J. Nicholas Physics and Applications of The Quantum Hall Effect...... 229 K. von Klitzing High Field Magnetotransport: Lecture III: The Fractional Quantum Hall Effect........... 249 R. J. Nicholas, R. G. Clark, A. Usher, J. R. Mallett, A. M. Suckling, J. J. Harris, and C. T. Foxon vii

OPTICAL PROPERTIES Optical Properties of Quantum Wells............... 261 C. Weisbuch Raman Spectroscopy for the Study of Semiconductor Heterostructures and Superlattices.......... 301 G. Abstreiter Far-Infrared Spectroscopy in Two-Dimensional Electronic Systems.... 317 D. Heitmann Magneto-optical Properties of Heterojunctions, Quantum Wells, and Superlattices.......... 347 J. C. Maan APPLICATIONS Band-gap Engineering for New Photonic and Electronic Devices.... 377 F. Capasso Hot-Electron Spectroscopy and Transistor Design........... 393 M. Kelly Novel Tunneling Structures: Physics and Device Implications..................... 403 M. J. Kelly, R. A. Davies, N. R. Couch, B. Movaghar and T. M. Kerr Opto-electronics in Semiconductor Quantum Wells Structures: Physics and Applications....... 423 D. S. Chemla INDEX........................... 437 viii