Synthesis and Characterization of Colloidal Lead Chalcogenide Quantum Dots and Progress Towards Single Photons On-demand

Synthesis and Characterization of Colloidal Lead Chalcogenide Quantum Dots and Progress Towards Single Photons On-demand PDF Author: Keith Alexander Abel
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Nanometer-sized semiconductor crystals, termed 'quantum dots', are of fundamental interest because of their size-tunable properties. Three-dimensional quantum confinement of charge carriers by the small crystal size results in discrete atomic-like electronic states. This dissertation describes the synthesis and in-depth characterization of lead chalcogenide colloidal quantum dots for forthcoming applications as near-infrared single photon emitters. An efficient single photon source that operates at telecommunication wavelengths (between 1.3 and 1.6?m) is a basic requirement for many photonic quantum technologies, such as quantum computing and quantum cryptography. Chapters 1 and 2 of this work provide an introduction to colloidal quantum dots and their use as single photon emitters. It includes a description of photonic crystal microcavities and their ability to enhance the spontaneous emission rate of quantum dots. The synthesis and basic characterization of PbSe and PbS quantum dots is then discussed in chapter 3. In particular, a new synthetic method for the preparation of highly photoluminescent PbS quantum dots is presented. PbSe/CdSe core/shell quantum dots prepared by a cation exchange reaction are also described and a significant improvement in photo-stability is shown. Chapter 3 concludes with a description of three different surface modification techniques. PbSe core and PbSe/CdSe core/shell materials are investigated further in chapter 4 by advanced characterization techniques that include high-angle annular dark field (HAADF) imaging, energy-filtered transmission electron microscopy (EF-TEM) imaging, energy-dependent X-ray photo-electron spectroscopy (XPS), small angle X-ray scattering (SAXS), and small angle neutron scattering (SANS). The information obtained from these techniques is combined to form a structural model of the PbSe core and PbSe/CdSe core/shell quantum dots with greater complexity than previously reported. In chapter 5, the temperature-dependent photoluminescence from PbSe and PbSe/CdSe core/shell quantum dots is discussed and a thermal model is presented that accounts for the large (non-trivial) temperature dependence of the Stokes shift and photoluminescence lineshape over the entire temperature range (4.5 to 295 K). Chapter 6 examines two scalable methods to integrate the colloidal quantum dots into silicon two-dimensional photonic crystal slab microcavities (a requirement for efficient single photon emission). Finally, conclusions and possible future work are discussed in chapter 7.

Synthesis and Characterization of Colloidal Lead Chalcogenide Quantum Dots and Progress Towards Single Photons On-demand

Synthesis and Characterization of Colloidal Lead Chalcogenide Quantum Dots and Progress Towards Single Photons On-demand PDF Author: Keith Alexander Abel
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Nanometer-sized semiconductor crystals, termed 'quantum dots', are of fundamental interest because of their size-tunable properties. Three-dimensional quantum confinement of charge carriers by the small crystal size results in discrete atomic-like electronic states. This dissertation describes the synthesis and in-depth characterization of lead chalcogenide colloidal quantum dots for forthcoming applications as near-infrared single photon emitters. An efficient single photon source that operates at telecommunication wavelengths (between 1.3 and 1.6?m) is a basic requirement for many photonic quantum technologies, such as quantum computing and quantum cryptography. Chapters 1 and 2 of this work provide an introduction to colloidal quantum dots and their use as single photon emitters. It includes a description of photonic crystal microcavities and their ability to enhance the spontaneous emission rate of quantum dots. The synthesis and basic characterization of PbSe and PbS quantum dots is then discussed in chapter 3. In particular, a new synthetic method for the preparation of highly photoluminescent PbS quantum dots is presented. PbSe/CdSe core/shell quantum dots prepared by a cation exchange reaction are also described and a significant improvement in photo-stability is shown. Chapter 3 concludes with a description of three different surface modification techniques. PbSe core and PbSe/CdSe core/shell materials are investigated further in chapter 4 by advanced characterization techniques that include high-angle annular dark field (HAADF) imaging, energy-filtered transmission electron microscopy (EF-TEM) imaging, energy-dependent X-ray photo-electron spectroscopy (XPS), small angle X-ray scattering (SAXS), and small angle neutron scattering (SANS). The information obtained from these techniques is combined to form a structural model of the PbSe core and PbSe/CdSe core/shell quantum dots with greater complexity than previously reported. In chapter 5, the temperature-dependent photoluminescence from PbSe and PbSe/CdSe core/shell quantum dots is discussed and a thermal model is presented that accounts for the large (non-trivial) temperature dependence of the Stokes shift and photoluminescence lineshape over the entire temperature range (4.5 to 295 K). Chapter 6 examines two scalable methods to integrate the colloidal quantum dots into silicon two-dimensional photonic crystal slab microcavities (a requirement for efficient single photon emission). Finally, conclusions and possible future work are discussed in chapter 7.

Synthesis and Structure of Colloidal Quantum Dots

Synthesis and Structure of Colloidal Quantum Dots PDF Author: Ingrid Joylyn Paredes
Publisher: American Chemical Society
ISBN: 0841299919
Category : Science
Languages : en
Pages : 120

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Book Description
Nanotechnology is an interdisciplinary field comprising materials scientists, chemists, physicists, and engineers dedicated to understanding the chemistry behind the associated synthesis, purification, modification, and applications. Already, nanotechnology has been instrumental to advances in medicine, electronics, catalysis, and cosmetics. The work of nanotechnologists has enabled society to move from the current “Silicon Age” into a new “Nano Age.” These alternatives to Si-based technologies are expected to combine the optoelectronic properties of bulk inorganic semiconductors with the benefits of additive device manufacturing—low cost, large area, and solution-based processes. This primer focuses on a class of nanomaterials known as colloidal quantum dots. Known for their solution processability and size-dependent optoelectronic properties, the study of colloidal quantum dots has garnered significant attention from the research community. The goal of this primer is to equip newcomers with the introductory knowledge and tools necessary to enter the field. As such, the scope of our work focuses on the synthesis and characterization of quantum dots; where possible, we point the reader to further reading specific to applications.

Ternary Quantum Dots

Ternary Quantum Dots PDF Author: Oluwatobi Samuel Oluwafemi
Publisher: Woodhead Publishing
ISBN: 0128183047
Category : Technology & Engineering
Languages : en
Pages : 282

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Book Description
Ternary Quantum Dots: Synthesis, Properties, and Applications reviews the latest advances in ternary (I-III-VI) chalcopyrite quantum dots (QDs), along with their synthesis, properties and applications. Sections address the fundamental key concepts of ternary quantum dots, progress in synthesis strategies (i.e., organic and aqueous synthesis), and characterization methods (i.e., transmission electron microscopy, dynamic light scattering, etc.). Properties of ternary quantum dots are comprehensively reviewed, including optical, chemical and physical properties. The factors and mechanisms of the cytotoxicity of ternary quantum dot-based nanomaterials are also described. Since ternary chalcopyrite quantum dots are less toxic and more environmentally benign than conventional binary II-VI chalcogenide quantum dots, they are being investigated to replace conventional quantum dots in a range of applications. Thus, this book reviews QDs in various applications, such as solar cells, photocatalytic, sensors and bio-applications. - Reviews fundamental concepts of ternary quantum dots and quantum dot-nanocomposites including the most relevant synthesis strategies, key properties, and characterization techniques - Delves into the cytotoxicity of quantum dots looking at the factors and mechanisms that influence cytotoxicity including demonstration of cytotoxicity assays for in vitro and in vivo tests - Touches on the many applications of ternary quantum dots including biomedical applications, applications in solar cells, sensing applications, and photocatalytic applications

Colloidal Quantum Dot Optoelectronics and Photovoltaics

Colloidal Quantum Dot Optoelectronics and Photovoltaics PDF Author: Gerasimos Konstantatos
Publisher: Cambridge University Press
ISBN: 0521198267
Category : Science
Languages : en
Pages : 329

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Book Description
Captures the most up-to-date research in the field, written in an accessible style by the world's leading experts.

Synthesis and Characterization of Colloidal Quantum Dots

Synthesis and Characterization of Colloidal Quantum Dots PDF Author: Melisa R. Greenberg
Publisher:
ISBN:
Category : Optoelectronic devices
Languages : en
Pages : 292

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Book Description


Quantum Dots

Quantum Dots PDF Author: Orion Ciftja
Publisher:
ISBN: 9781619429680
Category : Quantum dots
Languages : en
Pages : 0

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Book Description
Nanoscience and nanotechnology is continuously moving forward enabling the precise, controlled fabrication of structures and devices at atomic and molecular scales. Quantum dots are typically semiconductor nanocrystals that have gained tremendous attention due to their unique electronic, magnetic, chemical and optical properties. They have proven very useful in applications in many fields across the physical, engineering, chemical, biological and medical sciences. In this book, the authors give an overview of the progress and major research developments in the field of quantum dots over the past two decades. They specifically focus on discussing the cutting-edge applications in the fields of information technology, electronics, biotechnology, energy, medicine, cellular imaging and diagnostic bio-sensing.

Cadmium Telluride Quantum Dots

Cadmium Telluride Quantum Dots PDF Author: John Donegan
Publisher: CRC Press
ISBN: 9814316091
Category : Science
Languages : en
Pages : 244

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Book Description
In the last two decades, semiconductor quantum dots-small colloidal nanoparticles-have garnered a great deal of scientific interest because of their unique properties. Among nanomaterials, CdTe holds special technological importance as the only known II-VI material that can form conventional p-n junctions. This makes CdTe very important for the dev

Synthesis and Characterization of Lead-based Core-shell-shell Quantum Dots and Studies on Excitation-dependent Quantum Yield Measurement

Synthesis and Characterization of Lead-based Core-shell-shell Quantum Dots and Studies on Excitation-dependent Quantum Yield Measurement PDF Author: Jieming Cao
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Nano-sized semiconductors, known as quantum dots (QDs), are one of the hottest research areas in recent years. The energy gaps of QDs change with their diameters, giving them size-dependent optical properties. By controlling reaction conditions, people are able to make QDs that can emit in certain wavelength ranges. So far, QDs have shown great potential in telecommunication, bio-imaging, single-photon laser source, etc. This thesis starts with Chapter 1, which first introduces the finding of QDs and why they have such special properties. The quantum confinement and energy gap are discussed, followed by the absorption and emission of QDs. Moreover, the synthesis methods and mechanism involved are reviewed in brief.

Quantum Dots

Quantum Dots PDF Author: Rakshit Ameta
Publisher: Elsevier
ISBN: 0323858953
Category : Science
Languages : en
Pages : 393

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Book Description
Quantum Dots: Fundamentals, Synthesis and Applications compiles key information, along with practical guidance on quantum dot synthesis and applications. Beginning with an introduction, Part One highlights such foundational knowledge as growth mechanisms, shape and composition, electrochemical properties, and production scale-up for quantum dots. Part Two goes on to provide practical guides to key chemical, physical and biological methods for the synthesis of quantum dots, with Part Three reviewing the application of quantum dots and a range of important use cases, including photocatalysis, energy cells and medical imaging. Drawing on the knowledge of its expert authors, this comprehensive book provides practical guidance for all those who already study, develop or use quantum dots in their work. - Presents the foundational information needed to effectively understand and manipulate quantum dot properties - Consolidates key methods of quantum dot synthesis in a single volume - Reviews both current and future practical applications of quantum dots across a range of important fields

Semiconductor Quantum Dots

Semiconductor Quantum Dots PDF Author: Y. Masumoto
Publisher: Springer Science & Business Media
ISBN: 3662050013
Category : Technology & Engineering
Languages : en
Pages : 500

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Book Description
Semiconductor quantum dots represent one of the fields of solid state physics that have experienced the greatest progress in the last decade. Recent years have witnessed the discovery of many striking new aspects of the optical response and electronic transport phenomena. This book surveys this progress in the physics, optical spectroscopy and application-oriented research of semiconductor quantum dots. It focuses especially on excitons, multi-excitons, their dynamical relaxation behaviour and their interactions with the surroundings of a semiconductor quantum dot. Recent developments in fabrication techniques are reviewed and potential applications discussed. This book will serve not only as an introductory textbook for graduate students but also as a concise guide for active researchers.