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Download Giant Nanocrystal Quantum Dots As Stable And Efficient Down Conversion Phosphor For Led Based Solid State Lighting full books in PDF, epub, and Kindle. Read online Giant Nanocrystal Quantum Dots As Stable And Efficient Down Conversion Phosphor For Led Based Solid State Lighting ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!
Download or read book Giant Nanocrystal Quantum Dots as Stable and Efficient Down-Conversion Phosphor for LED Based Solid State Lighting written by and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
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Publisher :
ISBN 13 :
Total Pages : 3 pages
Book Rating : 4.:/5 (962 download)
Download or read book Engineered Core/shell Quantum Dots as Phosphors for Solid-state Lighting written by and published by . This book was released on 2015 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: Light-emitting diodes (LEDs) for solid state light ing (SSL) typically combine a blue or near- ultraviolet drive LED with one or more dow nconverting phosphors to produce "white" light. Further advances in both efficiency and wh ite-light quality will re quire new phosphors with narrow-band, highly efficient emission, particul arly in the red. A team led by principal investigator Dr. Victor Klim ov of Los Alamos National Labo ratory proposes to develop engineered semiconductor nanocrystal quantum dots (QDs) that combine optimal luminescent properties with long-term stability under ty pical downconverting conditions to enable new performance levels in SSL. The white LED phosphor industry is estimated to have sales of roughly $400 million in 2018 and would significantly benefit from the development of bright and narrow red-emitting QD phosphors because they woul d enable warmer whites without wasting energy by emission of light beyond the response of the human eye. In order to capitalize on the market opportunity, the LANL team is partnering with a local company called UbiQD that will facilitate US manufacturing.
Author : Gerasimos Konstantatos
Publisher : Cambridge University Press
ISBN 13 : 0521198267
Total Pages : 329 pages
Book Rating : 4.5/5 (211 download)
Download or read book Colloidal Quantum Dot Optoelectronics and Photovoltaics written by Gerasimos Konstantatos and published by Cambridge University Press. This book was released on 2013-11-07 with total page 329 pages. Available in PDF, EPUB and Kindle. Book excerpt: Captures the most up-to-date research in the field, written in an accessible style by the world's leading experts.
Author : Talha Erdem
Publisher : Springer
ISBN 13 : 9811358869
Total Pages : 79 pages
Book Rating : 4.8/5 (113 download)
Download or read book Color Science and Photometry for Lighting with LEDs and Semiconductor Nanocrystals written by Talha Erdem and published by Springer. This book was released on 2019-01-18 with total page 79 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book reviews the application of semiconductor nanocrystals also known as colloidal quantum dots (QDs) to LED lighting for indoors and outdoors as well as LED backlighting in displays, summarizing the color science of QDs for lighting and displays and presenting recent developments in QD-integrated LEDs and display research. By employing QDs in color-conversion LEDs, it is possible to simultaneously accomplish successful color rendition of the illuminated objects and a good spectral overlap between the emission spectrum of the light source and the sensitivity of the human eye at a warm white color temperature – something that is fundamentally challenging to achieve with conventional sources, such as incandescent and fluorescent lamps, and phosphor-based LEDs.
Author : Hong Meng
Publisher : John Wiley & Sons
ISBN 13 : 3527353275
Total Pages : 405 pages
Book Rating : 4.5/5 (273 download)
Download or read book Colloidal Quantum Dot Light Emitting Diodes written by Hong Meng and published by John Wiley & Sons. This book was released on 2024-02-20 with total page 405 pages. Available in PDF, EPUB and Kindle. Book excerpt: Explore all the core components for the commercialization of quantum dot light emitting diodes Quantum dot light emitting diodes (QDLEDs) are a technology with the potential to revolutionize solid-state lighting and displays. Due to the many applications of semiconductor nanocrystals, of which QDLEDs are an example, they also hold the potential to be adapted into other emerging semiconducting technologies. As a result, it is critical that the next generation of engineers and materials scientists understand these diodes and their latest developments. Colloidal Quantum Dot Light Emitting Diodes: Materials and Devices offers a comprehensive introduction to this subject and its most recent research advancements. Beginning with a summary of the theoretical foundations and the basic methods for chemically synthesizing colloidal semiconductor quantum dots, it identifies existing and future applications for these groundbreaking technologies. The result is tailored to produce a thorough understanding of this area of research. Colloidal Quantum Dot Light Emitting Diodes readers will also find: An author with decades of experience in the field of organic electronics Detailed discussion of topics including advanced display technologies, the patent portfolio and commercial considerations, and more Strategies and design techniques for improving device performance Colloidal Quantum Dot Light Emitting Diodes is ideal for material scientists, electronics engineers, inorganic and solid-state chemists, solid-state and semiconductor physicists, photochemists, and surface chemists, as well as the libraries that support these professionals.
Download or read book High Efficiency Colloidal Quantum Dot Phosphors written by and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The project showed that non-Cd containing, InP-based nanocrystals (semiconductor materials with dimensions of 6̃ nm) have high potential for enabling next-generation, nanocrystal-based, on chip phosphors for solid state lighting. Typical nanocrystals fall short of the requirements for on chip phosphors due to their loss of quantum efficiency under the operating conditions of LEDs, such as, high temperature (up to 150 °C) and high optical flux (up to 200 W/cm2). The InP-based nanocrystals invented during this project maintain high quantum efficiency (>80%) in polymer-based films under these operating conditions for emission wavelengths ranging from 5̃30 to 620 nm. These nanocrystals also show other desirable attributes, such as, lack of blinking (a common problem with nanocrystals which limits their performance) and no increase in the emission spectral width from room to 150 °C (emitters with narrower spectral widths enable higher efficiency LEDs). Prior to these nanocrystals, no nanocrystal system (regardless of nanocrystal type) showed this collection of properties; in fact, other nanocrystal systems are typically limited to showing only one desirable trait (such as high temperature stability) but being deficient in other properties (such as high flux stability). The project showed that one can reproducibly obtain these properties by generating a novel compositional structure inside of the nanomaterials; in addition, the project formulated an initial theoretical framework linking the compositional structure to the list of high performance optical properties. Over the course of the project, the synthetic methodology for producing the novel composition was evolved to enable the synthesis of these nanomaterials at a cost approximately equal to that required for forming typical conventional nanocrystals. Given the above results, the last major remaining step prior to scale up of the nanomaterials is to limit the oxidation of these materials during the tens of thousands of hours of LED operation. Once the LED phosphor lifetime specifications are met, these nanocrystals will enable white LEDs for solid state lighting to simultaneously have increased efficiency and improved light quality, in addition to enabling the creation of custom light spectrums. These improvements to white LEDs will help accelerate the adoption of SSL, leading to large savings in US and worldwide energy costs.
Author : N. Thejo Kalyani
Publisher : Woodhead Publishing
ISBN 13 : 0323852793
Total Pages : 612 pages
Book Rating : 4.3/5 (238 download)
Download or read book Quantum Dots written by N. Thejo Kalyani and published by Woodhead Publishing. This book was released on 2023-01-18 with total page 612 pages. Available in PDF, EPUB and Kindle. Book excerpt: Quantum dots: Emerging materials for versatile applications is an introduction to the fundamentals and important advances of research of this important category of semiconductor nanostructured materials. After a brief review of relevant nanotechnology concepts and the unique properties of nanomaterials, the book describes the fundamentals of quantum dots with definitions of the primary classifications of quantum dots. There is an emphasis on practical considerations of the commercial translation of quantum dots such as their toxicity, stability, and disposal. Moreover, the book focuses on a review of the advances in research in emerging quantum dot materials along with the latest innovations in materials design and fabrication methods. Quantum Dots is suitable for materials scientists and engineers in academia or industry R&D who are looking for an introduction to this research topic or a key reference on the latest advances and applications. Introduces the primary classifications, properties, synthesis, characterization and fabrication strategies of quantum dots Reviews the latest applications of quantum dots for LEDs, displays, energy storage devices, photovoltaic cells, medicine, and more Discusses the practical barriers to commercial translation of quantum dots, including toxicity, stability, and their safe disposal
Author : Morteza Sasani Ghamsari
Publisher : BoD – Books on Demand
ISBN 13 : 9535135759
Total Pages : 171 pages
Book Rating : 4.5/5 (351 download)
Download or read book Quantum-dot Based Light-emitting Diodes written by Morteza Sasani Ghamsari and published by BoD – Books on Demand. This book was released on 2017-10-25 with total page 171 pages. Available in PDF, EPUB and Kindle. Book excerpt: Quantum dot-based light emitting diodes were assigned to bringing together the latest and most important progresses in light emitting diode (LED) technologies. In addition, they were dedicated to gain the perspective of LED technology for all of its advancements and innovations due to the employment of semiconductor nanocrystals. Highly selective, the primary aim was to provide a visual source for high-urgency work that will define the future directions relating to the organic light emitting diode (OLED), with the expectation for lasting scientific and technological impact. The editor hopes that the chapters verify the realization of the mentioned aims that have been considered for editing of this book. Due to the rapidly growing OLED technology, we wish this book to be useful for any progress that can be achieved in future.
Download or read book "Giant" Nanocrystal Quantum Dots for Light-emission Applications written by and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Yasuaki Masumoto
Publisher : Springer Science & Business Media
ISBN 13 : 9783540428053
Total Pages : 520 pages
Book Rating : 4.4/5 (28 download)
Download or read book Semiconductor Quantum Dots written by Yasuaki Masumoto and published by Springer Science & Business Media. This book was released on 2002-05-28 with total page 520 pages. Available in PDF, EPUB and Kindle. Book excerpt: Growth of Self Organized Quantum Dots / J.-S. Lee / - Excitonic Structures and Optical Properties of Quantum Dots / Toshihide Takagahara / - Electron-Phonon Interactions in Semiconductor Quantum Dots / Toshihide Takagahara / - Micro-Imaging and Single Dot Spectroscopy of Self Assembled Quantum Dots / Mitsuru Sugisaki / - Persistent Spectral Hole Burning in Semiconductor Quantum Dots / Yasuaki Masumoto / - Dynamics of Carrier Relaxation in Self Assembled Quantum Dots / Ivan V. Ignatiev, Igor E. Kozin / - Resonant Two-Photon Spectroscopy of Quantum Dots / Alexander Baranov / - Homogeneous Width of Confined Excitons in Quantum Dots - Experimental / Yasuaki Masumoto / - Theory of Exciton Dephasing in Semiconductor Quantum Dots / Toshihide Takagahara / - Excitonic Optical Nonlinearity and Weakly Correlated Exciton-Pair States / Selvakumar V. Nair, Toshihide Takagahara / - Coulomb Effects in the Optical Spectra of Highly Excited Semiconductor Quantum Dots / Selvakumar V. Nair / - Device ...
Author : Xin Tong
Publisher : Springer Nature
ISBN 13 : 3030742709
Total Pages : 319 pages
Book Rating : 4.0/5 (37 download)
Download or read book Quantum Dot Photodetectors written by Xin Tong and published by Springer Nature. This book was released on 2021-09-17 with total page 319 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a comprehensive overview of state-of-the-art quantum dot photodetectors, including device fabrication technologies, optical engineering/manipulation strategies, and emerging photodetectors with building blocks of novel quantum dots (e.g. perovskite) as well as their hybrid structured (e.g. 0D/2D) materials. Semiconductor quantum dots have attracted much attention due to their unique quantum confinement effect, which allows for the facile tuning of optical properties that are promising for next-generation optoelectronic applications. Among these remarkable properties are large absorption coefficient, high photosensitivity, and tunable optical spectrum from ultraviolet/visible to infrared region, all of which are very attractive and favorable for photodetection applications. The book covers both fundamental and frontier research in order to stimulate readers' interests in developing novel ideas for semiconductor photodetectors at the center of future developments in materials science, nanofabrication technology and device commercialization. The book provides a knowledge sharing platform and can be used as a reference for researchers working in the fields of photonics, materials science, and nanodevices.
Author :
Publisher :
ISBN 13 :
Total Pages : 143 pages
Book Rating : 4.:/5 (925 download)
Download or read book Science-based Design of Stable Quantum Dots for Energy-efficient Lighting written by and published by . This book was released on 2015 with total page 143 pages. Available in PDF, EPUB and Kindle. Book excerpt: II-VI quantum dots, such as CdSe and CdTe, are attractive as downconversion materials for solid-state lighting, because of their narrow linewidth, tunable emission. However, for these materials to have acceptable quantum yields (QYs) requires that they be coated with a II-VI shell material whose valence band offset serves to confine the hole to the core. Confinement prevents the hole from accessing surface traps that lead to nonradiative decay of the exciton. Examples of such hole-confined core/shell QDs include CdTe/CdSe and CdSe/CdS. Unfortunately, the shell can also cause problems due to lattice mismatch, which ranges from 4-6% for systems of interest. This lattice mismatch can create significant interface energies at the heterojunction and places the core under radial compression and the shell under tangential tension. At elevated temperatures (~240°C) interfacial diffusion can relax these stresses, as can surface reconstruction, which can expose the core, creating hole traps. But such high temperatures favor the hexagonal Wurtzite structure, which has lower QY than the cubic zinc blende structure, which can be synthesized at lower temperatures, ~140°C. In the absence of alloying the core/shell structure can become metastable, or even unstable, if the shell is too thick. This can cause result in an irregular shell or even island growth. But if the shell is too thin thermallyactivated transport of the hole to surface traps can occur. In our LDRD we have developed a fundamental atomistic modeling capability, based on Stillinger-Weber and Bond-Order potentials we developed for the entire II-VI class. These pseudo-potentials have enabled us to conduct large-scale atomistic simulations that have led to the computation of phase diagrams of II-VI QDs. These phase diagrams demonstrate that at elevated temperatures the zinc blende phase of CdTe with CdSe grown on it epitaxially becomes thermodynamically unstable due to alloying. This is accompanied by a loss of hole confinement and a severe drop in the QY and emission lifetime, which is confirmed experimentally for the zinc blende core/shell QDs prepared at low temperatures. These QDs have QYs as high as 95%, which makes them very attractive for lighting. Finally, to address strain relaxation in these materials we developed a model for misfit dislocation formation that we have validated through atomistic simulations.
Author : Peng Yu
Publisher : Springer Nature
ISBN 13 : 3030358135
Total Pages : 329 pages
Book Rating : 4.0/5 (33 download)
Download or read book Quantum Dot Optoelectronic Devices written by Peng Yu and published by Springer Nature. This book was released on 2020-04-16 with total page 329 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book captures cutting-edge research in semiconductor quantum dot devices, discussing preparation methods and properties, and providing a comprehensive overview of their optoelectronic applications. Quantum dots (QDs), with particle sizes in the nanometer range, have unique electronic and optical properties. They have the potential to open an avenue for next-generation optoelectronic methods and devices, such as lasers, biomarker assays, field effect transistors, LEDs, photodetectors, and solar concentrators. By bringing together leaders in the various application areas, this book is both a comprehensive introduction to different kinds of QDs with unique physical properties as well as their preparation routes, and a platform for knowledge sharing and dissemination of the latest advances in a novel area of nanotechnology.
Download or read book Process-Dependent Properties in Colloidally Synthesized?Giant? Core/Shell Nanocrystal Quantum Dots written by and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Due to their characteristic bright and stable photoluminescence, semiconductor nanocrystal quantum dots (NQDs) have attracted much interest as efficient light emitters for applications from single-particle tracking to solid-state lighting. Despite their numerous enabling traits, however, NQD optical properties are frustratingly sensitive to their chemical environment, exhibit fluorescence intermittency ('blinking'), and are susceptible to Auger recombination, an efficient nonradiative decay process. Previously, we showed for the first time that colloidal CdSe/CdS core/shell nanocrystal quantum dots (NQDs) comprising ultrathick shells (number of shell monolayers, n,> 10) grown by protracted successive ionic layer adsorption and reaction (SILAR) leads to remarkable photostability and significantly suppressed blinking behavior as a function of increasing shell thickness. We have also shown that these so-called 'giant' NQDs (g-NQDs) afford nearly complete suppression of non-radiative Auger recombination, revealed in our studies as long biexciton lifetimes and efficient multiexciton emission. The unique behavior of this core/shell system prompted us to assess correlations between specific physicochemical properties - beyond shell thickness - and functionality. Here, we demonstrate the ability of particle shape/faceting, crystalline phase, and core size to determine ensemble and single-particle optical properties (quantum yield/brightness, blinking, radiative lifetimes). Significantly, we show how reaction process parameters (surface-stabilizing ligands, ligand:NQD ratio, choice of 'inert' solvent, and modifications to the SILAR method itself) can be tuned to modify these function-dictating NQD physical properties, ultimately leading to an optimized synthetic approach that results in the complete suppression of blinking. We find that the resulting 'guiding principles' can be applied to other NQD compositions, allowing us to achieve non-blinking behavior in the near-infrared. Lastly, in addition to realizing novel light-emission properties by refining nanoscale architectures at the single-NQD level, we also investigate collective properties by assembling our core/shell NQDs into larger scale arrays.
Author : Siddharth Sampat
Publisher :
ISBN 13 :
Total Pages : 182 pages
Book Rating : 4.:/5 (972 download)
Download or read book Exploring Ultrafast Dynamics of Excitons and Multiexcitons in "giant" Nanocrystal Quantum Dots written by Siddharth Sampat and published by . This book was released on 2016 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this work, we have performed extensive time resolved photoluminescence (PL) studies to further the understanding of charge dynamics in semiconductor nanocrystal quantum dots (QDs). Recent developments in QD synthesis have introduced a new set of QD known as “giant” quantum dots (gQDs) that consist of a CdSe core coated with up to 19 monolayers of a CdS shell. The thick shell layer is grown using a SILAR method resulting in a defect free, alloyed CdSe/CdS interface. This has been attributed to gQDs exhibiting excellent optical properties such as high excitonic quantum yield (QY), prolonged photostability and inhibition of flourescence intermittency (“blinking”), which is regularly observed in conventional QDs. In gQDs, however, owing to unique fabrication methods and material selection, the Auger process is strongly suppressed resulting in efficient radiative recombination of photogenerated excitons as well as high PL QY of charged excitonic and multiexcitonic species. We perform extensive single gQDs studies that establish the role played by gQD shell thickness and core size in governing their optical properties. It is found that both the core and shell dimensions can be tuned in order to achieve the smallest gQDs with the highest vii Auger suppression resulting in photostable dots with high QYs. Next, we perform a study of multiexcitonic species in gQDs that are encapsulated in an insulating SiO2shell. These silica-coated gQDs exhibit strong PL from charged excitons, biexcitons as well as triexcitons. This observation has led to an accurate description of excitonic and multiexcitonic behavior which is modeled using a statistical scaling approach. As a demonstration of the practical applicability of gQDs, energy transfer of excitons as well as multiexcitons to different substrates is studied. Finally, a back gated silicon nanomembrane FET device is discussed that exhibits a large photocurrent increase when sensitized with QDs.
Author : Rodolph Donovan
Publisher :
ISBN 13 : 9781681173207
Total Pages : 304 pages
Book Rating : 4.1/5 (732 download)
Download or read book Quantum Dots - Theory and Applications written by Rodolph Donovan and published by . This book was released on 2016-04-01 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt: A quantum dot is a nanoparticle made of any semiconductor material such as silicon, cadmium selenide, cadmium sulfide, or indium arsenide. Quantum dots may be able to increase the efficiency of solar cells. In normal solar cells, a photon of light generates one electron. Experiments with both silicon quantum dots and lead sulfide quantum dots can generate two electrons for a single photon of light. Therefore, using quantum dots in solar cells could significantly increase their efficiency in producing electric power. Quantum dots (QD) are nanoscale semiconductor devices that tightly confine either electrons or electron holes in all three spatial dimensions. They can be made through several possible routes including colloidal synthesis, plasma synthesis, or mechanical fabrication. The electronic properties of the quantum dots fall between those of bulk semiconductors and those of discrete molecules of comparable size, and optoelectronic properties such as band gap, can be tuned as a function of particle size and shape for a given composition. Because of the high tunability of properties, QDs are of interest in many research applications such as transistors, solar cells, LEDs, and diode lasers. For instance, the ability of QDs to precisely convert and tune a spectrum makes them ideal for LCD displays. Previous LCD displays can waste energy converting red-green poor, blue-yellow rich white light into a more balanced lighting. By using QDs, only the necessary colors for ideal images are contained in the screen. The result is a screen that is brighter, clearer, and more energy-efficient. Researchers are also working on the use of quantum dots in displays for applications ranging from your cell phone to large screen televisions that would consume less power than current displays. By placing different size quantum dots in each pixel of a display screen, the red, green, and blue colors used to generate the full spectrum of colors would be available. The book Quantum Dots - Theory and Applications covers some new research results in the field of fundamental excitations, decoherence, charge states, epitaxial techniques and photoluminescence experiments related to devices made with quantum dots also includes numerous applications of quantum dots.
Download or read book Giant Multishell CdSe Nanocrystal Quantum Dots with Suppressed Blinking written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
