This is an overview of different models and mechanisms developed to describe the capture and relaxation of carriers in quantum-dot systems. Despite their undisputed importance, the mechanisms leading to population and energy exchanges between a quantum dot and its environment are not yet fully understood. The authors develop a first-order approach to such effects, using elementary quantum mechanics and an introduction to the physics of semiconductors. The book results from a series of lectures given by the authors at the Master’s level.
This is an overview of different models and mechanisms developed to describe the capture and relaxation of carriers in quantum-dot systems. Despite their undisputed importance, the mechanisms leading to population and energy exchanges between a quantum dot and its environment are not yet fully understood. The authors develop a first-order approach to such effects, using elementary quantum mechanics and an introduction to the physics of semiconductors. The book results from a series of lectures given by the authors at the Master’s level.
This multidisciplinary book provides up-to-date coverage of carrier and spin dynamics and energy transfer and structural interaction among nanostructures. Coverage also includes current device applications such as quantum dot lasers and detectors, as well as future applications to quantum information processing. The book will serve as a reference for anyone working with or planning to work with quantum dots.
Today’s semiconductor memory market is divided between two types of memory: DRAM and Flash. Each has its own advantages and disadvantages. While DRAM is fast but volatile, Flash is non-volatile but slow. A memory system based on self-organized quantum dots (QDs) as storage node could combine the advantages of modern DRAM and Flash, thus merging the latter’s non-volatility with very fast write times. This thesis investigates the electronic properties of and carrier dynamics in self-organized quantum dots by means of time-resolved capacitance spectroscopy and time-resolved current measurements. The first aim is to study the localization energy of various QD systems in order to assess the potential of increasing the storage time in QDs to non-volatility. Surprisingly, it is found that the major impact of carrier capture cross-sections of QDs is to influence, and at times counterbalance, carrier storage in addition to the localization energy. The second aim is to study the coupling between a layer of self-organized QDs and a two-dimensional hole gas (2DHG), which is relevant for the read-out process in memory systems. The investigation yields the discovery of the many-particle ground states in the QD ensemble. In addition to its technological relevance, the thesis also offers new insights into the fascinating field of nanostructure physics.
Semiconductor nanocrystals and metal nanoparticles are the building blocks of the next generation of electronic, optoelectronic, and photonic devices. Covering this rapidly developing and interdisciplinary field, the book examines in detail the physical properties and device applications of semiconductor nanocrystals and metal nanoparticles. It begins with a review of the synthesis and characterization of various semiconductor nanocrystals and metal nanoparticles and goes on to discuss in detail their optical, light emission, and electrical properties. It then illustrates some exciting applications of nanoelectronic devices (memristors and single-electron devices) and optoelectronic devices (UV detectors, quantum dot lasers, and solar cells), as well as other applications (gas sensors and metallic nanopastes for power electronics packaging). Focuses on a new class of materials that exhibit fascinating physical properties and have many exciting device applications. Presents an overview of synthesis strategies and characterization techniques for various semiconductor nanocrystal and metal nanoparticles. Examines in detail the optical/optoelectronic properties, light emission properties, and electrical properties of semiconductor nanocrystals and metal nanoparticles. Reviews applications in nanoelectronic devices, optoelectronic devices, and photonic devices.
Semiconductor quantum optics is on the verge of moving from the lab to real world applications. When stepping from basic research to new technologies, device engineers will need new simulation tools for the design and optimization of quantum light sources, which combine classical device physics with cavity quantum electrodynamics. This thesis aims to provide a holistic description of single-photon emitting diodes by bridging the gap between microscopic and macroscopic modeling approaches. The central result is a novel hybrid quantum-classical model system that self-consistently couples semi-classical carrier transport theory with open quantum many-body systems. This allows for a comprehensive description of quantum light emitting diodes on multiple scales: It enables the calculation of the quantum optical figures of merit together with the simulation of the spatially resolved current flow in complex, multi-dimensional semiconductor device geometries out of one box. The hybrid system is shown to be consistent with fundamental laws of (non-)equilibrium thermodynamics and is demonstrated by numerical simulations of realistic devices.
This book provides guidelines and design rules for developing high-performance, low-cost, and energy-efficient quantum-dot (QD) lasers for silicon photonic integrated circuits (PIC), optical frequency comb generation, and quantum information systems. To this end, the nonlinear properties and dynamics of QD lasers on silicon are investigated in depth by both theoretical analysis and experiment. This book aims at addressing four issues encountered in developing silicon PIC: 1) The instability of laser emission caused by the chip-scale back-reflection. During photonic integration, the chip-scale back-reflection is usually responsible for the generation of severe instability (i.e., coherence collapse) from the on-chip source. As a consequence, the transmission performance of the chip could be largely degraded. To overcome this issue, we investigate the nonlinear properties and dynamics of QD laser on Si in this book to understand how can it be applied to isolator-free photonic integration in which the expensive optical isolator can be avoided. Results show that the QD laser exhibits a high degree of tolerance for chip-scale back-reflections in absence of any instability, which is a promising solution for isolator-free applications. 2) The degradation of laser performance at a high operating temperature. In this era of Internet-of-Thing (IoT), about 40% of energy is consumed for cooling in the data center. In this context, it is important to develop a high-temperature continuous-wave (CW) emitted laser source. In this book, we introduce a single-mode distributed feedback (DFB) QD laser with a design of optical wavelength detuning (OWD). By taking advantage of the OWD technique and the high-performance QD with high thermal stability, all the static and dynamical performances of the QD device are improved when the operating temperature is high. This study paves the way for developing uncooled and isolator-free PIC. 3) The limited phase noise level and optical bandwidth of the laser are the bottlenecks for further increasing the transmission capacity. To improve the transmission capacity and meet the requirement of the next generation of high-speed optical communication, we introduce the QD-based optical frequency comb (OFC) laser in this book. Benefiting from the gain broadening effect and the low-noise properties of QD, the OFC laser is realized with high optical bandwidth and low phase noise. We also provide approaches to further improve the laser performance, including the external optical feedback and the optical injection. 4) Platform with rich optical nonlinearities is highly desired by future integrated quantum technologies. In this book, we investigate the nonlinear properties and four-wave mixing (FWM) of QD laser on Si. This study reveals that the FWM efficiency of QD laser is more than ten times higher than that of quantum-well laser, which gives insight into developing a QD-based silicon platform for quantum states of light generation. Based on the results in this book, scientists, researchers, and engineers can come up with an informed judgment in utilizing the QD laser for applications ranging from classical silicon PIC to integrated quantum technologies.
Nanometre sized structures made of semiconductors, insulators, and metals and grown by modern growth technologies or by chemical synthesis exhibit novel electronic and optical phenomena due to the confinement of electrons and photons. Strong interactions between electrons and photons in narrow regions lead to inhibited spontaneous emission, thresholdless laser operation, and Bose-Einstein condensation of exciton-polaritons in microcavities. Generation of sub-wavelength radiation by surface plasmon-polaritons at metal-semiconductor interfaces, creation of photonic band gaps in dielectrics, and realization of nanometer sized semiconductor or insulator structures with negative permittivity and permeability, known as metamaterials, are further examples in the area of Nanophotonics. The studies help develop spasers and plasmonic nanolasers of subwavelength dimensions, paving the way to use plasmonics in future data centres and high-speed computers working at THz bandwidth with less than a few fJ/bit dissipation. The present book is aimed at graduate students and researchers providing them with an introductory textbook on Semiconductor Nanophotonics. It gives an introduction to electron-photon interactions in Quantum Wells, Wires, and Dots and then discusses the processes in microcavities, photonic band gap materials, metamaterials, and related applications. The phenomena and device applications under strong light-matter interactions are discussed, mostly by using classical and semi-classical theories. Numerous examples and problems accompany each chapter.
Provides a comprehensive survey of fundamental concepts and methods for optoelectronic device modeling and simulation. Gives a broad overview of concepts with concise explanations illustrated by real results. Compares different levels of modeling, from simple analytical models to complex numerical models. Discusses practical methods of model validation. Includes an overview of numerical techniques.
Compound Semiconductors 2004 was the 31st Symposium in this distinguished international series, held at Hoam Convention Center of Seoul National University, Seoul, Korea from September 12 to September 16, 2004. It attracted over 180 submissions from leading scientists in academic and industrial research institutions, and remains a major forum for t
