Author: Lewis H. Fowler-Gerace Publisher: ISBN: Category : Languages : en Pages : 0
Book Description
Spatially indirect excitons (IXs), also known as interlayer excitons, are bound pairs of an electron and a hole in spatially separated layers. IXs can propagate over long distances before they recombine into light, and they can cool down below the temperature of quantum degeneracy within their lifetimes, which can be controlled by gate voltage up to microseconds and beyond. These properties make IXs a promising platform for studying fundamental physics phenomena and as the medium for highly efficient signal processing devices. IXs were originally studied in gallium arsenide (GaAs) heterostructures, where IXs have shown evidence for Bose-Einstein condensation, and proof of principle has been demonstrated for excitonic transistors and excitonic integrated circuits. IXs only exist at low temperatures in GaAs systems due to the low IX binding energy on the order of 10 meV. In the transition-metal dichalcogenide (TMD) heterostructure system, the IX binding energy is predicted to be more than two orders of magnitude higher, making IXs stable at room temperature and allowing for the possibility of high temperature IX superfluidity. To date, observation of some of the key IX behaviors, namely the long-range IX transport and evidence of IX condensation, has remained elusive in the TMD system. This dissertation characterizes the IX spectrum in a MoSe2/WSe2 heterostructure, demonstrates the realization and control of long-range IX propagation using a new mechanism beyond the know mechanism for IX control in GaAs heterostructures, and separately identifies a quantum origin for the propagation of IXs generated by resonant excitation in the TMD heterostructure.
Author: Erica Calman Publisher: ISBN: Category : Languages : en Pages : 53
Book Description
Excitons are quasi-partciles consisting of an electro-statically bound electron and hole which have long been observed in semiconducting and insulating materials. A spatially indirect exciton (IX) is an exciton in which the electron and the hole are spatially separated. This is achieved through the use of a static electric field and engineered semiconductor heterosteructures. Indirect excitons interact with one another and can effeciently re-radiate, so they provide a means for light to interact with light in solid media, and can thus be used for ecient optical signal processing. However, the most common material for studying indirect excitons (GaAs) cannot support excitons at temperatures above ~ 100 K. This limitation, due to hermal fluctuations having enough energy to cause exciton dissocation prevents the creation of practical devices for excitonic signal processing. This dissertation demonstrates an increase in the binding energy and thus operating temperature of indirect excitons by utelizing van der Waals transition metal dichalcogenide heterostructures. These atomically thin materials have binding energies on the order of 0:5 eV which support excitons at 300 K.
Author: Publisher: Elsevier ISBN: 0443193932 Category : Science Languages : en Pages : 270
Book Description
Semiconductors and Semimetals series, highlights new advances in the field, with this new volume presenting interesting chapters. Each chapter is written by an international board of authors. - Provides the latest information on cancer research - Offers outstanding and original reviews on a range of cancer research topics - Serves as an indispensable reference for researchers and students alike
Author: Eui-Hyeok Yang Publisher: Elsevier ISBN: 0128184760 Category : Technology & Engineering Languages : en Pages : 502
Book Description
Synthesis, Modelling and Characterization of 2D Materials and Their Heterostructures provides a detailed discussion on the multiscale computational approach surrounding atomic, molecular and atomic-informed continuum models. In addition to a detailed theoretical description, this book provides example problems, sample code/script, and a discussion on how theoretical analysis provides insight into optimal experimental design. Furthermore, the book addresses the growth mechanism of these 2D materials, the formation of defects, and different lattice mismatch and interlayer interactions. Sections cover direct band gap, Raman scattering, extraordinary strong light matter interaction, layer dependent photoluminescence, and other physical properties. - Explains multiscale computational techniques, from atomic to continuum scale, covering different time and length scales - Provides fundamental theoretical insights, example problems, sample code and exercise problems - Outlines major characterization and synthesis methods for different types of 2D materials
Author: Zongyu Huang Publisher: CRC Press ISBN: 1000562840 Category : Science Languages : en Pages : 166
Book Description
Monoelemental 2D materials called Xenes have a graphene-like structure, intra-layer covalent bond, and weak van der Waals forces between layers. Materials composed of different groups of elements have different structures and rich properties, making Xenes materials a potential candidate for the next generation of 2D materials. 2D Monoelemental Materials (Xenes) and Related Technologies: Beyond Graphene describes the structure, properties, and applications of Xenes by classification and section. The first section covers the structure and classification of single-element 2D materials, according to the different main groups of monoelemental materials of different components and includes the properties and applications with detailed description. The second section discusses the structure, properties, and applications of advanced 2D Xenes materials, which are composed of heterogeneous structures, produced by defects, and regulated by the field. Features include: Systematically detailed single element materials according to the main groups of the constituent elements Classification of the most effective and widely studied 2D Xenes materials Expounding upon changes in properties and improvements in applications by different regulation mechanisms Discussion of the significance of 2D single-element materials where structural characteristics are closely combined with different preparation methods and the relevant theoretical properties complement each other with practical applications Aimed at researchers and advanced students in materials science and engineering, this book offers a broad view of current knowledge in the emerging and promising field of 2D monoelemental materials.
Author: Arash Rahimi-Iman Publisher: Springer Nature ISBN: 303069352X Category : Science Languages : en Pages : 288
Book Description
This book introduces the wider field of functional nanomaterials sciences, with a strong emphasis on semiconductor photonics. Whether you are studying photonic quantum devices or just interested in semiconductor nanomaterials and their benefits for optoelectronic applications, this book offers you a pedagogical overview of the relevant subjects along with topical reviews. The book discusses different yet complementary studies in the context of ongoing international research efforts, delivering examples from both fundamental and applied research to a broad readership. In addition, a hand-full of useful optical techniques for the characterization of semiconductor quantum structures and materials are addressed. Moreover, nanostructuring methods for the production of low-dimensional systems, which exhibit advantageous properties predominantly due to quantum effects, are summarized. Science and engineering professionals in the interdisciplinary domains of nanotechnology, photonics, materials sciences, and quantum physics can familiarize themselves with selected highlights with eyes towards photonic applications in the fields of two-dimensional materials research, light–matter interactions, and quantum technologies.
Author: Lewis H. Fowler-Gerace
Author: Erica Calman
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Author: Eui-Hyeok Yang
Author: James Howarth
Author: Zongyu Huang
Author: Simone Latini
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Author: Willy Knorr
Author: Arash Rahimi-Iman