Springer Series in Solid-State Sciences 194 Michael Kneissl Andreas Knorr Stephan Reitzenstein Axel Hoffmann   Editors Semiconductor Nanophotonics Materials, Models, and Devices Springer Series in Solid-State Sciences Volume 194 Series Editors Klaus von Klitzing, Max Planck Institute for Solid State Research, Stuttgart, Germany Roberto Merlin, Department of Physics, University of Michigan, Ann Arbor, MI, USA Hans-Joachim Queisser, MPI für Festkörperforschung, Stuttgart, Germany Bernhard Keimer, Max Planck Institute for Solid State Research, Stuttgart, Germany Armen Gulian, Institute for Quantum Studies, Chapman University, Ashton, MD, USA Sven Rogge, Physics, UNSW, Sydney, NSW, Australia TheSpringerSeriesinSolid-StateSciencesconsistsoffundamentalscientificbooks prepared by leading researchers in the field. They strive to communicate, in a systematic and comprehensive way, the basic principles as well as new developments in theoretical and experimental solid-state physics. More information about this series at http://www.springer.com/series/682 Michael Kneissl Andreas Knorr (cid:129) (cid:129) Stephan Reitzenstein Axel Hoffmann (cid:129) Editors Semiconductor Nanophotonics Materials, Models, and Devices 123 Editors Michael Kneissl Andreas Knorr Institute of Solid State Physics Institute of Theoretical Physics Technische UniversitätBerlin Technische UniversitätBerlin Berlin, Germany Berlin, Germany StephanReitzenstein AxelHoffmann Institute of Solid State Physics Institute of Solid State Physics Technische UniversitätBerlin Technische UniversitätBerlin Berlin, Germany Berlin, Germany ISSN 0171-1873 ISSN 2197-4179 (electronic) SpringerSeries inSolid-State Sciences ISBN978-3-030-35655-2 ISBN978-3-030-35656-9 (eBook) https://doi.org/10.1007/978-3-030-35656-9 ©SpringerNatureSwitzerlandAG2020 Thisworkissubjecttocopyright.AllrightsarereservedbythePublisher,whetherthewholeorpart of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission orinformationstorageandretrieval,electronicadaptation,computersoftware,orbysimilarordissimilar methodologynowknownorhereafterdeveloped. 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ThisSpringerimprintispublishedbytheregisteredcompanySpringerNatureSwitzerlandAG Theregisteredcompanyaddressis:Gewerbestrasse11,6330Cham,Switzerland Preface This book is a compendium of twelve years of research within the collaborative research centre “Semiconductor Nanophotonics” (CRC 787) which was funded by the German Research Foundation (DFG) between 2008 and 2019. Although all CRC787projectscontributedtothebook,itisnotmeanttobemereprojectreport. InadditiontosummarizingkeyresearchresultsofCRC787,thebookisintendedto provide a broad overview of the state-of-the-art in the development of semicon- ductor nanostructures and nanophotonic devices. Consequently, all book chapters were organized along with key scientific topics with contributions from different projects interwoven within thematic chapters. It covers epitaxial growth and the structural characteristics of group III-arsenide and III-nitride semiconductor mate- rials and nanostructures, the description of fundamental optic, electronic, and vibronicpropertiesofnanomaterialsaswellasthedesignandrealizationofawide range of semiconductor nanophotonic devices. After a brief introduction into basic features and applications of semiconductor nanophotonicdevicesinChap.1,theChap.2coverstheepitaxialgrowthaswellas structural, electronic, and optical properties of InAs submonolayer quantum dots andtheirapplicationinsemiconductoropticalamplifiersandlasers.Thisdiscussion iscomplementedbyareviewofsite-controllednucleationofInGaAsquantumdots using the buried stressor growth mode in Chap. 3, which concludes with a demonstration of single-photon emission from an electrically driven quantum light source based on a site-controlled quantum dot. The ultrafast carrier and photon dynamicsinsemiconductorsquantumdotsandnanophotonicdevicesarepresented in Chap. 4 including the dynamics of optical gain spectra and their application in optical amplifiers, laser diodes, and multi-section mode-locked laser devices. The Chap. 5 focuses on the description of a series of advanced nanoscale characteri- zation tools, encompassing scanning transmission electron microscopy cathodolu- minescence (STEM-CL), tip-enhanced Raman spectroscopy (TERS), microphotoluminescence (µPL), high-resolution X-ray diffraction (XRD), and cross-sectionalscanningtunnellingmicroscopyandspectroscopy(STM/STS).This chapter also covers the growth of III-nitride nanowires and nanorods as well as analysis of their structural and optical properties. It is followed by Chap. 6 v vi Preface presenting a microscopic description of light emission from quantum dots and coupled quantum dot—microcavity structures with respect to their correlated photon emission statistics. It provides a comprehensive examination of individual electronic excitations such as excitons, the fundamental Coulomb interaction betweentheelectronicstatesaswellastheircouplingtootherquasiparticlessuchas phonons and photons. Furthermore, phenomena such as photon entanglement and intrabandspectroscopyarereviewed.Buildingonthesefundamentaldescriptionsof light emission in the quantum regime of light–matter interaction, Chap. 7 presents basic concepts and numerical methods for the self-consistent modelling and multi-dimensional simulation of a wide range of semiconductor nanophotonic devices. Recent advances in device-scale modelling of electrically driven quantum-dot-based single-photon sources and laser diodes are described creating newnumerictoolsinthedesignanddevelopmentoffutureintegratedlightsources and quantum devices. In Chap. 8, deterministic fabrication technologies for quantum-dot-based sources of single photons and entangled-photon pairs for applications in optical quantum communication systems are discussed. This includes the controlled integration of quantum dots into microlenses for enhanced photon-extraction efficiency, the deterministic fabrication of on-chip integrated quantum circuits with high functionality as well as cutting-edge quantum-optical measurements. Building on this, Chap. 9 describes quantum networks based on single-photon emitters and covers topics like frequency conversion of quantum light, single-photon storage and quantum repeaters, quantum key distribution pro- tocols, and the demonstration of a free-space optical link as a test bed for a future quantum network. Chapter 10 reviews vertical-cavity surface-emitting laser diodes (VCSELs), another critical nanophotonic device with a wide range of applications in optical data communication systems, photonic-electronic integrated circuits as well as sensing and tracking systems. Different VCSEL designs including high contrastgratingsandVCSELarrays,aswellasvariouskeyfabricationtechnologies will be discussed, and the performance characteristics of VCSEL devices with recordultra-highmodulationbandwidthsandenergy efficiencies willbepresented. Silicon photonic interconnect technologies based on VCSELs emitting at tele- and datacom wavelengths are examined in Chap. 11. Incoherent, as well as coherent VCSEL-basedtransmissionlinks,e.g.usingquadraturephase-shiftkeying(QPSK), arepresentedandanalysed.ThefinaltwochaptersarededicatedtogroupIII-nitride materials and devices. In Chap. 12, microcavities with InGaN quantum wells or GaNquantumdotsasactivemediumareexploredasbuildingblocksforelectrically driven surface-emitting lasers and room-temperature single-photon emitters. Key componentslikedistributedBraggmirrorsinthevisibletodeepUVspectralrange aswellasthestructural,electronic,andopticalpropertiesofGaNquantumdotsand microcavities will be discussed. Finally, Chap. 13 explores the realization of current-injectionAlGaN-basedlaserdiodesemittinginthedeepultravioletspectral range. This includes the fabrication of low defect density AlN templates, the pseudomorphic growth of AlGaN laser heterostructures, advanced fabrication technologiesforohmiccontactformationandtunnelinjection,andtheinvestigation of optical gain and losses in deep UV lasers. Preface vii We like to express our appreciation to all the co-authors for their important contributions to the extensive chapters of this book. This book represents a truly joint effort with a total of 67 co-authors contributing to its content including all principal investigators of the third phase of CRC 787 as well as a number of postdoctoral researchers and Ph.D. students. We would also like to thank the German Research Foundation, in particular, Dr. Michael Mößle and Mrs. Brit Redöhl,aswellasallthemembersoftheDFGgrantcommitteefortheircontinued support over this twelve-year journey. Last but not least, a special “Thank you” goes to Thomas Kure, scientific secretary of the CRC 787, for his dedicated effort andorganizationalskillsthatwerecrucialinordertobringallcontributionstogether in a timely, coherent, and smooth manner. Berlin, Germany Michael Kneissl Andreas Knorr Stephan Reitzenstein Axel Hoffmann Contents 1 A Short Introduction to Semiconductor Nanophotonics . . . . . . . . . 1 Michael Kneissl 1.1 Nanophotonics and Internet Traffic . . . . . . . . . . . . . . . . . . . . . 1 1.2 Nanophotonics and Cyber Security . . . . . . . . . . . . . . . . . . . . . 4 1.3 Economic Impact of Nanophotonics. . . . . . . . . . . . . . . . . . . . . 6 1.4 Semiconductor Nanophotonics. . . . . . . . . . . . . . . . . . . . . . . . . 8 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 2 Submonolayer Quantum Dots. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 N. Owschimikow, B. Herzog, B. Lingnau, K. Lüdge, A. Lenz, H. Eisele, M. Dähne, T. Niermann, M. Lehmann, A. Schliwa, A. Strittmatter and U. W. Pohl 2.1 Carrier Localization in Quantum Dots . . . . . . . . . . . . . . . . . . . 14 2.1.1 Stranski-Krastanow and Submonolayer Quantum Dots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 2.1.2 Electronic Structure of InAs Submonolayer Quantum Dots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 2.2 Epitaxy of Submonolayer Quantum Dots . . . . . . . . . . . . . . . . . 21 2.2.1 InAs/GaAs Submonolayers . . . . . . . . . . . . . . . . . . . . . 21 2.2.2 InAs/GaAs Submonolayers with Antimony . . . . . . . . . 22 2.3 Atomic Structure of Submonolayer Quantum Dots . . . . . . . . . . 25 2.3.1 Methods for Structural Analysis . . . . . . . . . . . . . . . . . 25 2.3.2 Analysis of InAs Submonolayer Depositions . . . . . . . . 27 2.3.3 Analysis of InAs Submonolayer Depositions with Antimony. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 2.4 Optical and Excitonic Properties . . . . . . . . . . . . . . . . . . . . . . . 34 2.4.1 InAs Submonolayer Quantum-Dot Ensembles . . . . . . . 34 2.4.2 InAs:Sb Submonolayer Quantum-Dot Ensembles . . . . . 38 ix x Contents 2.5 Devices Based on Submonolayer Quantum Dots . . . . . . . . . . . 41 2.5.1 Gain and Efficiency . . . . . . . . . . . . . . . . . . . . . . . . . . 41 2.5.2 Amplitude-Phase Coupling . . . . . . . . . . . . . . . . . . . . . 44 2.6 Conclusion and Perspectives . . . . . . . . . . . . . . . . . . . . . . . . . . 46 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 3 Stressor-Induced Site Control of Quantum Dots for Single-Photon Sources. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 U. W. Pohl, A. Strittmatter, A. Schliwa, M. Lehmann, T. Niermann, T. Heindel, S. Reitzenstein, M. Kantner, U. Bandelow, T. Koprucki and H.-J. Wünsche 3.1 Site-Controlled Nucleation of Quantum Dots . . . . . . . . . . . . . . 53 3.2 Simulation of Strain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 3.2.1 Model for Strain Simulation . . . . . . . . . . . . . . . . . . . . 55 3.2.2 Strain in a Mesa and in a Lamella Structure . . . . . . . . 56 3.3 Nucleation Control by a Buried Aperture Stressor . . . . . . . . . . 59 3.3.1 Development of a Buried-Stressor Design . . . . . . . . . . 60 3.3.2 Proof-of-Principle for Stressor-Controlled Nucleation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 3.3.3 Site-Control of Single Quantum Dots . . . . . . . . . . . . . 63 3.4 Strain Measurement Applying Electron Holography . . . . . . . . . 65 3.4.1 Reconstruction of the Strain Tensor. . . . . . . . . . . . . . . 65 3.4.2 Phase Analysis of Dark-Field Electron Holography . . . 67 3.4.3 Strain Analysis in a Lamella of a GaAs Mesa . . . . . . . 69 3.5 Single-Photon Source Based on Stressor-Induced Site Control of Quantum Dots . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 3.5.1 Development of an Electroluminescence Quantum-Dot Diode. . . . . . . . . . . . . . . . . . . . . . . . . . 73 3.5.2 Operation Characteristics of a Single-Photon Source. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 3.5.3 Development of a Resonant-Cavity Structure. . . . . . . . 76 3.6 Realization of an Efficient Current Injection into a Single Quantum Dot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 3.6.1 Modeling of the Current Flow in the Device . . . . . . . . 81 3.6.2 Current Confinement in pin and ppn Designs. . . . . . . . 84 3.6.3 Demonstration of a ppn QD Diode with Efficient Current Confinement . . . . . . . . . . . . . . . . . . . . . . . . . 85 3.7 Conclusion and Perspectives . . . . . . . . . . . . . . . . . . . . . . . . . . 86 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87