Read Books Online and Download eBooks, EPub, PDF, Mobi, Kindle, Text Full Free.
Optical Properties Of Colloidal Germanium Nanocrystals
Download Optical Properties Of Colloidal Germanium Nanocrystals full books in PDF, epub, and Kindle. Read online Optical Properties Of Colloidal Germanium Nanocrystals ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!
Book Synopsis Optical Properties of Colloidal Germanium Nanocrystals by :
Download or read book Optical Properties of Colloidal Germanium Nanocrystals written by and published by . This book was released on 2000 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: Highly crystalline germanium (Ge) nanocrystals in the size range 2--10 nm were grown in inverse micelles and purified and size-separated by high pressure liquid chromatography with on-line optical and electrical diagnostics. The nanocrystals retain the diamond structure of bulk Ge down to at least 2.0 nm (containing about 150 Ge atoms). The background- and impurity-free extinction and photoluminescence (PL) spectra of these nanocrystals revealed rich structure which was interpreted in terms of the bandstructure of Ge shifted to higher energies by quantum confinement. The shifts ranged from -0.1 eV to over 1 eV for the various transitions. PL in the range 350--700 nm was observed from nanocrystals 2--5 nm in size. The 2.0 nm nanocrystals yielded the most intense PL (at 420 nm) which is believed to be intrinsic and attributed to direct recombination at [Gamma]. Excitation at high energy (250 nm) populates most of the conduction bands resulting in competing recombination channels and the observed broad PL spectra.
Book Synopsis Nonlinear Optical Properties of Germanium Nanocrystals in Silica by : Annette Roslyn Dowd
Download or read book Nonlinear Optical Properties of Germanium Nanocrystals in Silica written by Annette Roslyn Dowd and published by . This book was released on 2000 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Ab Initio Investigations of the Intrinsic Optical Properties of Germanium and Silicon Nanocrystals by : Hans-Christian Weißker
Download or read book Ab Initio Investigations of the Intrinsic Optical Properties of Germanium and Silicon Nanocrystals written by Hans-Christian Weißker and published by . This book was released on 2004 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Optical Properties of Nanocrystals by : Zeno Gaburro
Download or read book Optical Properties of Nanocrystals written by Zeno Gaburro and published by SPIE-International Society for Optical Engineering. This book was released on 2002 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume provides an accessible and informative introduction to Dante's work (especially the Commedia) and its place in literary history. It shows how this work emerges from, and relates to, the cultural geography and history of the writer's time; what its major themes are; and how it has been interpreted and appropriated by subsequent writers and artists, particularly in the English-speaking world.
Book Synopsis Semiconductor Nanocrystals and Metal Nanoparticles by : Tupei Chen
Download or read book Semiconductor Nanocrystals and Metal Nanoparticles written by Tupei Chen and published by CRC Press. This book was released on 2016-10-14 with total page 526 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Book Synopsis Optical Properties of Semiconductor Nanocrystals by : S. V. Gaponenko
Download or read book Optical Properties of Semiconductor Nanocrystals written by S. V. Gaponenko and published by Cambridge University Press. This book was released on 1998-10-28 with total page 263 pages. Available in PDF, EPUB and Kindle. Book excerpt: Examines the optical properties of low-dimensional semiconductor structures, a hot research area - for graduate students and researchers.
Book Synopsis The Electronic and Optical Properties of Colloidal Lead-selenide Semiconductor Nanocrystals by : Jeffrey Matthew Harbold
Download or read book The Electronic and Optical Properties of Colloidal Lead-selenide Semiconductor Nanocrystals written by Jeffrey Matthew Harbold and published by . This book was released on 2005 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis The Synthesis and Characterization of Germanium Nanoparticles and Nanowires and the Study of Their Potential in Photovoltaics by : Stephen Corey Codoluto
Download or read book The Synthesis and Characterization of Germanium Nanoparticles and Nanowires and the Study of Their Potential in Photovoltaics written by Stephen Corey Codoluto and published by . This book was released on 2009 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The increasing energy demand of an overpopulated society has bolstered the interest in exploring renewable energy forms, one of which is solar energy. Current solar cell technology is neither an efficient nor cost-effective alternative to currently used fossil fuels. Nanostructured semiconductor building blocks are expected to play a central role in the development of next-generation cost-effective solar cell technology. Among the various materials that have been explored and studied, Ge holds particular promise due to it favorable band gap and good transport characteristic. A method to produce colloidal Ge nanocrystals, however, has not yet been established. Colloidal synthesis provides a scalable and cost-effective route to nanocrystalline semiconductor material as building blocks in low-cost PV energy conversion devices. This work describes the synthesis and characterization of Ge nanoparticles and Ge nanowires and their potential applications. Ge nanoparticles, 1.9 - 16.0 nm, are synthesized via colloidal synthesis by reducing germanium iodide using a strong reducing agent in various coordinating solvents. The effects of reaction and injection temperature, reaction time, and initial concentration are studied. A minimum temperature of 250 °C is required to crystallize Ge in a colloidal synthesis, below which only amorphous material is formed. An increase in reaction temperature from 250 to 300 °C has little effect on the final nanocrystal size and structure. A temperature of 200 °C was found to minimize crystal growth defects. Increasing or decreasing the injection temperature increased the crystal defects. The final crystalline products are analyzed using XRD, FTIR, TEM, HR-TEM, SEM, UV-vis spectroscopy, and PL to study oxidation, crystal structure, and optical properties. Spin coated germanium nanoparticles are combined with sputtered a-Si to create a polysilicon-Ge matrix which could direct charge transfer and decrease recombination of photogenerated charges. As a complementary nanocrystalline Ge building block nanowires were also synthesized by the thermal decomposition of DPG and TMG in supercritical hexane using a batch and a semicontinuous supercritical reactor. Up to 210 mg are synthesized and collected using this process with a diameter range of 20 nm to 60 nm and lengths up to 15 [MICRO SIGN]m. The continuously grown nanowire experimental yield is ~35%, compared to the batch experimental yield of 15%. The Ge nanowires were easily extracted from the collection vessel and characterized using TEM, SEM, and XRD to confirm the presence of Ge and to study the structure of the wires.
Book Synopsis Dekker Encyclopedia of Nanoscience and Nanotechnology by : James A. Schwarz
Download or read book Dekker Encyclopedia of Nanoscience and Nanotechnology written by James A. Schwarz and published by CRC Press. This book was released on 2004 with total page 988 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Colloidal Nanocrystals with Near-infrared Optical Properties by : Matthew George Panthani
Download or read book Colloidal Nanocrystals with Near-infrared Optical Properties written by Matthew George Panthani and published by . This book was released on 2011 with total page 382 pages. Available in PDF, EPUB and Kindle. Book excerpt: Colloidal nanocrystals with optical properties in the near-infrared (NIR) are of interest for many applications such as photovoltaic (PV) energy conversion, bioimaging, and therapeutics. For PVs and other electronic devices, challenges in using colloidal nanomaterials often deal with the surfaces. Because of the high surface-to-volume ratio of small nanocrystals, surfaces and interfaces play an enhanced role in the properties of nanocrystal films and devices. Organic ligand-capped CuInSe2 (CIS) and Cu(InXGa1-X)Se2 (CIGS) nanocrystals were synthesized and used as the absorber layer in prototype solar cells. By fabricating devices from spray-coated CuInSe nanocrystals under ambient conditions, solar-to-electric power conversion efficiencies as high as 3.1% were achieved. Many treatments of the nanocrystal films were explored. Although some treatments increased the conductivity of the nanocrystal films, the best devices were from untreated CIS films. By modifying the reaction chemistry, quantum-confined CuInSeXS2-X (CISS) nanocrystals were produced. The potential of the CISS nanocrystals for targeted bioimaging was demonstrated via oral delivery to mice and imaging of nanocrystal fluorescence. The size-dependent photoluminescence of Si nanocrystals was measured. Si nanocrystals supported on graphene were characterized by conventional transmission electron microscopy and spherical aberration (Cs)-corrected scanning transmission electron microscopy (STEM). Enhanced imaging contrast and resolution was achieved by using Cs-corrected STEM with a graphene support. In addition, clear imaging of defects and the organic-inorganic interface was enabled by utilizing this technique.
Book Synopsis Self-Assembly of Nanostructures by : Stefano Bellucci
Download or read book Self-Assembly of Nanostructures written by Stefano Bellucci and published by Springer Science & Business Media. This book was released on 2011-10-27 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the third volume in a series of books on selected topics in Nanoscale Science and Technology based on lectures given at the well-known Istituto Nazionale di Fisica Nucleare (INFN) schools of the same name. The present set of notes stems in particular from the participation and dedication of prestigious lecturers, such as Nunzio Motta, Fulvia Patella, Alexandr Toropov, and Anna Sgarlata. All lectures have been carefully edited and reworked, taking into account extensive follow-up discussions. A tutorial lecture by Motta et al. presents the analysis of the Poly(3-hexylthiophene) self assembly on carbon nanotubes and discusses how the interaction between the two materials forms a new hybrid nanostructure, with potential application to future solar cells technology. In their contribution, Patella et al. review quantum dots of III-V compounds, which offer appealing perspectives for more sophisticated applications in new generation devices such as single-photon emitters for nano-photonics and quantum computing. Focusing on self-assembled quantum dots, the chapter by Alexandr Toropov et al. provides a comprehensive review of some important aspects in the formation of quantum dots and presents the results of the authors’ extensive investigation of the features of droplet epitaxy. The fourth contribution, by Sgarlata et al., focuses on recent progress toward controlled growth of self-assembled nanostructures, dealing with the shaping, ordering and localization in Ge/Si heteroepitaxy and reviewing recent results on the self-organization of Ge nanostructures at Si surfaces.
Book Synopsis Optical and Material Properties of Colloidal Semiconductor Nanocrystals by :
Download or read book Optical and Material Properties of Colloidal Semiconductor Nanocrystals written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: PhD.
Book Synopsis Colloidal Synthesis and Characterization of Pristine and Compositionally Manipulated Germanium Nanocrystals by : Katayoon Tabatabaei
Download or read book Colloidal Synthesis and Characterization of Pristine and Compositionally Manipulated Germanium Nanocrystals written by Katayoon Tabatabaei and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A tremendous amount of research efforts were focused on conventional compound semiconductor nanomaterials. Group IV (Si and Ge) semiconducting materials in nanoscale are of significant research interest due to their unique and promising properties in a broad range of technological applications. While during the last two decades, Ge NCs as non-toxic alternatives over metal chalcogenides or group III-V quantum dots were studied by different research group to tune their optical and electronic properties by controlling their size, morphology, surface functionality and composition, still insufficient understanding is at their disposal to design and achieve well-defined and high quality Ge nanostructures for the targeting applications. Nanogermanium is a material that has great potential for technological applications and doped and alloyed Ge nanocrystals (NCs) are actively being considered. The presented work is focused on the microwave-assisted solution-based synthesis of germanium nanocrystals with insights to their formation, manipulating their composition using Group V element and achieving a better understanding of the synthetic chemistry of these materials.Chapter 1 provides an overview of fundamental concepts in the synthesis, nucleation, growth processes, surface chemistry and composition manipulation of NCs and in particular, germanium nanocrystals (Ge NCs). Chapter 2 presents the incorporation of bismuth (Bi), an n-type dopant, within or at the surface of Ge NCs. Bi classically shows no solubility in crystalline Ge. However, Ge could be doped kinetically with Bi in the nanoregime. The first colloidal synthesis in a microwave-assisted solution route and characterization of Bi-doped Ge NCs have been presented. The oleylamine capping ligand can be replaced by dodecanethiol without loss of Bi. A positive correlation between the lattice parameter and the concentration of Bi content (0.5 - 2.0 mol %) has been shown via PXRD and SAED. XPS, TEM, STEM and ICP-MS are consistent with the Bi solubility up to 2 mol %. The NC size increases with increasing amount of bismuth iodide employed in the reaction. Absorption data show that the band gap of the Bi-doped Ge NCs is consistent with the NC size. This work shows that a new element can be doped into Ge NCs via a microwave-assisted route in amounts as high as 1-2 mol % and leads to increased carriers. Colloidal chemistry provides an inroad to new materials not accessible via other means. Chapter 3 discusses a finer control of absolute size and crystallinity that can be achieved by the addition of molecular iodine (I2) and bromine (Br2) to germanium(II) iodide (GeI2). I2 and Br2 are shown to oxidize GeI2 to GeI4 in-situ, providing good control over size and crystallinity. The kinetics of Br2 oxidation of GeI2 are slightly different, but both I2 and Br2 provide size control of the Ge NCs. The samples are highly crystalline as indicated by powder X-ray diffraction (PXRD), selected area electron diffraction (SAED), transmission electron microscopy (TEM), and Raman spectroscopy. The solutions of I2, GeI2, and colloidal Ge NCs were investigated with Fourier- transform infrared (FTIR) and proton nuclear magnetic resonance (1H NMR) and showed no evidence for imine, hydrazine, or nitrile formation. Hydrogen and ammonia gases were detected after the reaction by gas chromatography (GC) and high-resolution mass spectrometry (HRMS). The presence of a germanium amine iodide complex was also confirmed with no evidence for a hydrazine-like species. These results suggest an efficient fine-tuning of size and crystallinity of Ge NCs using halogens in addition to the mixed-valence precursor synthetic protocol previously reported. Chapter 4 considers Bi halide precursors (BiCl3 and BiBr3) along with an organobismuth precursor (Bi(OTf)3 for their impact on size control of Bi-doped Ge NCs. In this work, using Bi halide precursors regardless of halide anion nature alters the NCs size. Higher precursor concentration also results in greater anisotropy in morphology. While BiI3 compared to BiCl3 and BiBr3 provides larger NCs sizes, especially in high concentration regime, all three halide precursors lead to size variation. However, using the organobismuth Bi(OTf)3 as a precursor maintains a relatively constant absolute size of the Ge NCs with low Bi precursor concentrations (0.0-1.0 mol %) and more significant changes can be observed with higher Bi content. The successful incorporation of Bi using Bi(OTf)3 into Ge NCs was determined by elemental mapping performed using scanning electron microscopy (SEM)-energy dispersive X-ray spectroscopy (EDS). It shows using the organobismuth precursor (Bi(OTf)3) promises to prevent a dramatic change of NCs sizes even when varying precursor concentration which is of paramount importance for many applications requiring a narrow and uniform size regime of doped Ge NCs. Finally, Chapter 5 presents the composition manipulation of Ge NCs, with another n-type group V element, antimony (Sb), a more common dopant for different semiconductor materials. Sb shows negligible solubility in bulk Ge, however, the kinetically controlled colloidal synthesis allows it to be incorporated in Ge or to reside on its surface. Oleylamine (OAm), OAm-trioctylphosphine (TOP)-capped Sb-doped Ge NCs have been synthesized for the first time by a microwave-assisted colloidal route. An enhancement of the lattice parameter of Ge NCs with increasing Sb concentration (0.0-1.0 mol %) is observed by PXRD. An increase in NCs diameters with higher content of SbI3 is shown by TEM. XPS and EDS confirm the presence of Sb before and after removal of OAm, TOP through hydrazine treatment and exchanging the Ge NCs surface with dodecanethiol suggesting either a strong Sb interaction with Ge surface or its incorporation within the lattice. Passivating the Ge surface by a binary ligand system of OAm, TOP results in formation of consistently larger NCs compared to OAm only. The TOP coordination to the Ge surface is confirmed by 31P NMR and SEM-EDS measurement. This Chapter presents successful synthesis of Sb-doped Ge NCs through colloidal chemistry and opens up new pathways to expand the composition chemistry of group IV semiconducting materials.
Book Synopsis Synthesis and Characterization of Embedded Ge Nanocrystals by : Qing Xu
Download or read book Synthesis and Characterization of Embedded Ge Nanocrystals written by Qing Xu and published by . This book was released on 2006 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Nanotechnology and Photovoltaic Devices by : Jan Valenta
Download or read book Nanotechnology and Photovoltaic Devices written by Jan Valenta and published by CRC Press. This book was released on 2015-06-01 with total page 441 pages. Available in PDF, EPUB and Kindle. Book excerpt: Silicon is an abundant element and is produced in large quantities for the electronic industry. The falling price of this commodity also feeds the growth of solar photovoltaics (PV). However, solar cells (SCs) based on bulk semiconductors have quite limited maximum attainable performance. Therefore, new principles and materials are being investigat
Book Synopsis System-Materials Nanoarchitectonics by : Yutaka Wakayama
Download or read book System-Materials Nanoarchitectonics written by Yutaka Wakayama and published by Springer Nature. This book was released on 2022-01-03 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is the first publication to widely introduce the contributions of nanoarchitectonics to the development of functional materials and systems. The book opens up pathways to novel nanotechnology based on bottom-up techniques. In fields of nanotechnology, theoretical and practical limitations are expected in the bottom-up nanofabrication process. Instead, some supramolecular processes for nano- and microstructure formation including molecular recognition, self-assembly, and template synthesis have gained great attention as novel key technologies to break through expected limitations in current nanotechnology. This volume describes future images of nanotechnology and related materials and device science as well as practical applications for energy and biotechnology. Readers including specialists, non-specialists, graduate students, and undergraduate students can focus on the parts of the book that interest and concern them most. Target fields include materials chemistry, organic chemistry, physical chemistry, nanotechnology, and even biotechnology.
Book Synopsis Optical Properties of Ion-doped ZnSe Colloidal Nanocrystals by : Chenli Gan
Download or read book Optical Properties of Ion-doped ZnSe Colloidal Nanocrystals written by Chenli Gan and published by . This book was released on 2007 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt:
