Tuning Semiconducting And Metallic Quantum Dots

Nanotechnology is one of the growing areas of this century, also opening new horizons for tuning optical properties. This book introduces basic tuning schemes, including those on a single quantum object level, with an emphasis on surface and interface manipulation of semiconducting and metallic quantum dots. There are two opposing demands in current forefront applications of quantum dots as optical labels, namely high luminescence stability (suppression of luminescence intermittency) and controllable intermittency and bleaching on a single-particle level to facilitate super-resolution optical microscopy (for which Eric Betzig, Stefan W. Hell, and William E. Moerner were awarded the 2014 Nobel Prize in Chemistry). The book discusses these contradictory demands with respect to both an understanding of the basic processes and applications. The chapters are a combination of scholarly presentation and comprehensive review and include case studies from the authors’ research, including unpublished results. Special emphasis is on a detailed understanding of spectroscopic and dynamic properties of semiconducting quantum dots. The book is suitable for senior undergraduates and researchers in the fields of optical nanoscience, materials science, and nanotechnology.

Nanotechnology is one of the growing areas of this century, also opening new horizons for tuning optical properties. This book introduces basic tuning schemes, including those on a single quantum object level, with an emphasis on surface and interface manipulation of semiconducting and metallic quantum dots. There are two opposing demands in current forefront applications of quantum dots as optical labels, namely high luminescence stability (suppression of luminescence intermittency) and controllable intermittency and bleaching on a single-particle level to facilitate super-resolution optical microscopy (for which Eric Betzig, Stefan W. Hell, and William E. Moerner were awarded the 2014 Nobel Prize in Chemistry). The book discusses these contradictory demands with respect to both an understanding of the basic processes and applications. The chapters are a combination of scholarly presentation and comprehensive review and include case studies from the authors’ research, including unpublished results. Special emphasis is on a detailed understanding of spectroscopic and dynamic properties of semiconducting quantum dots. The book is suitable for senior undergraduates and researchers in the fields of optical nanoscience, materials science, and nanotechnology.

The current state and perspectives in natural and life sciences are strongly linked to the development of novel complex organic-inorganic materials at various levels of organization, including semiconductor quantum dots (QDs) and QD-based nanostructures with unique optical and physico-chemical properties. This book provides a comprehensive description of the morphology and main physico-chemical properties of self-assembled inorganic-dye nanostructures as well as some applications in the field of nanotechnology. It crosses disciplines to examine essential nanoassembly principles of QD interaction with organic molecules, excited state dynamics in nanoobjects, theoretical models, and methodologies. Based on ensemble and single-nanoobject detection, the book quantitatively shows (for the first time on a series of nanoassemblies) that surface-mediated processes (formation of trap states) dictate the probability of several of the most interesting and potentially useful photophysical phenomena (FRET- or non-FRET-induced quenching of QD photoluminescence) observed for colloidal QDs and QD–dye nanoassemblies. Further, nanostructures can be generated by nanolithography and thereafter selectively decorated with dye molecules. A similar approach applies to natural nanosized surface heterogeneities.

This book presents invited reviews and original short notes of recent results obtained in studies concerning the fabrication and application of nanostructures, which hold great promise for the new generation of electronic, optoelectronic and energy conversion devices. They present achievements discussed at Special Sessions "Frontiers of Molecular Diagnostics with Nanostructures" and "Nanoelectromagnetics" organized within Nanomeeting-2017. Discussing exciting and relatively new topics such as fast-progressing nanoelectronics and optoelectronics, molecular electronics and spintronics, nanoelectromagnetics, nanophotonics, nanosensorics and nanoenergetics as well as nanotechnology and quantum processing of information, this book gives readers a more complete understanding of the practical applications of nanotechnology and nanostructures.

Semiconductor Quantum Dots presents an overview of the background and recent developments in the rapidly growing field of ultrasmall semiconductor microcrystallites, in which the carrier confinement is sufficiently strong to allow only quantized states of the electrons and holes. The main emphasis of this book is the theoretical analysis of the confinement induced modifications of the optical and electronic properties of quantum dots in comparison with extended materials. The book develops the theoretical background material for the analysis of carrier quantum-confinement effects, introduces the different confinement regimes for relative or center-of-mass motion quantization of the electron-hole-pairs, and gives an overview of the best approximation schemes for each regime. A detailed discussion of the carrier states in quantum dots is presented and surface polarization instabilities are analyzed, leading to the self-trapping of carriers near the surface of the dots. The influence of spin-orbit coupling on the quantum-confined carrier states is discussed. The linear and nonlinear optical properties of small and large quantum dots are studied in detail and the influence of the quantum-dot size distribution in many realistic samples is outlined. Phonons in quantum dots as well as the influence of external electric or magnetic fields are also discussed. Last but not least the recent developments dealing with regular systems of quantum dots are also reviewed. All things included, this is an important piece of work on semiconductor quantum dots not to be dismissed by serious researchers and physicists. Contents: IntroductionTheoretical Concepts, Quantum Confinement RegimesElectron-Hole-Pair StatesOptical Properties of Small DotsOptical Properties of Large DotsPhonons and External FieldsCoupled Quantum DotsAppendix: Asymptotic Cluster Growth Laws Readership: Condensed matter physicists, researchers in laser and optical science. keywords:Absorption;Configuration Interaction;Confinement Energy;Excitons;Biexcitons;Confinement Regime;Spin-Orbit Coupling;Angular Momentum

Quantum dots (QDs) are luminescent semiconductor nanocrystals with unique chemical and physical properties due to their size and highly compact structure. QDs were first proposed for use in luminescent concentrators to replace organic dye molecules. In this book, the interest is in taking advantage of the emission properties of QDS, which can be tuned by their size, resulting from quantum confinement. In addition, the book discusses the potential of QDs as contrast and therapeutic agents in the field of medicine.

This is the first book to specifically focus on semiconductor nanocrystals, and address their synthesis and assembly, optical properties and spectroscopy, and potential areas of nanocrystal-based devices. The enormous potential of nanoscience to impact on industrial output is now clear. Over the next two decades, much of the science will transfer into new products and processes. One emerging area where this challenge will be very successfully met is the field of semiconductor nanocrystals. Also known as colloidal quantum dots, their unique properties have attracted much attention in the last twenty years.