Author: 郭欣Publisher:
ISBN:
Category : Molecular beam epitaxy
Languages : en
Pages : 0
Book Description
Molecular Beam Epitaxy of Three Dimensional Topological Insulator Bi2Se3 Thin Films
Author: 郭欣Publisher:
ISBN:
Category : Molecular beam epitaxy
Languages : en
Pages : 0
Book Description
Molecular Beam Epitaxy of Three Dimensional Topological Insulator Bi₂se₃ Thin Films
Author: Xin GuoMolecular Beam Epitaxy
Author: Mohamed HeniniPublisher: Elsevier
ISBN: 0128121378
Category : Science
Languages : en
Pages : 790
Book Description
Molecular Beam Epitaxy (MBE): From Research to Mass Production, Second Edition, provides a comprehensive overview of the latest MBE research and applications in epitaxial growth, along with a detailed discussion and 'how to' on processing molecular or atomic beams that occur on the surface of a heated crystalline substrate in a vacuum. The techniques addressed in the book can be deployed wherever precise thin-film devices with enhanced and unique properties for computing, optics or photonics are required. It includes new semiconductor materials, new device structures that are commercially available, and many that are at the advanced research stage. This second edition covers the advances made by MBE, both in research and in the mass production of electronic and optoelectronic devices. Enhancements include new chapters on MBE growth of 2D materials, Si-Ge materials, AIN and GaN materials, and hybrid ferromagnet and semiconductor structures. - Condenses the fundamental science of MBE into a modern reference, speeding up literature review - Discusses new materials, novel applications and new device structures, grounding current commercial applications with modern understanding in industry and research - Includes coverage of MBE as mass production epitaxial technology and how it enhances processing efficiency and throughput for the semiconductor industry and nanostructured semiconductor materials research community
Molecular Beam Epitaxy of Topological Insulator Bi2Se3
Author: Yuxuan ChenPublisher:
ISBN:
Category :
Languages : en
Pages : 32
Book Description
In this thesis, I show my effort in growing atomically flat Bi2Se3 thin films using molecular beam epitaxy (MBE) method. Bi2Se3 is a kind of topological insulator, whose exotic surface states have been found in the samples that I grew.
Molecular Beam Epitaxy
Author: Hajime AsahiPublisher: John Wiley & Sons
ISBN: 111935501X
Category : Science
Languages : en
Pages : 510
Book Description
Covers both the fundamentals and the state-of-the-art technology used for MBE Written by expert researchers working on the frontlines of the field, this book covers fundamentals of Molecular Beam Epitaxy (MBE) technology and science, as well as state-of-the-art MBE technology for electronic and optoelectronic device applications. MBE applications to magnetic semiconductor materials are also included for future magnetic and spintronic device applications. Molecular Beam Epitaxy: Materials and Applications for Electronics and Optoelectronics is presented in five parts: Fundamentals of MBE; MBE technology for electronic devices application; MBE for optoelectronic devices; Magnetic semiconductors and spintronics devices; and Challenge of MBE to new materials and new researches. The book offers chapters covering the history of MBE; principles of MBE and fundamental mechanism of MBE growth; migration enhanced epitaxy and its application; quantum dot formation and selective area growth by MBE; MBE of III-nitride semiconductors for electronic devices; MBE for Tunnel-FETs; applications of III-V semiconductor quantum dots in optoelectronic devices; MBE of III-V and III-nitride heterostructures for optoelectronic devices with emission wavelengths from THz to ultraviolet; MBE of III-V semiconductors for mid-infrared photodetectors and solar cells; dilute magnetic semiconductor materials and ferromagnet/semiconductor heterostructures and their application to spintronic devices; applications of bismuth-containing III–V semiconductors in devices; MBE growth and device applications of Ga2O3; Heterovalent semiconductor structures and their device applications; and more. Includes chapters on the fundamentals of MBE Covers new challenging researches in MBE and new technologies Edited by two pioneers in the field of MBE with contributions from well-known MBE authors including three Al Cho MBE Award winners Part of the Materials for Electronic and Optoelectronic Applications series Molecular Beam Epitaxy: Materials and Applications for Electronics and Optoelectronics will appeal to graduate students, researchers in academia and industry, and others interested in the area of epitaxial growth.
MBE Growth of Alinn and Bi2se3 Thin Films and Hetero-Structures
Author: ZIYAN. WANGPublisher:
ISBN: 9781361285336
Category :
Languages : en
Pages :
Book Description
This dissertation, "MBE Growth of AlInN and Bi2Se3 Thin Films and Hetero-structures" by Ziyan, Wang, 王子砚, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Molecular Beam Epitaxy is an advanced method for the synthesis of single-crystal thin-film structures. However, the growth behavior varies case by case due to the complicated kinetic process. In this thesis, the epitaxial growth processes of AlxIn1-xN alloy and Bi2Se3 thin-films are studied. Heteroepitaxial growth of AlxIn1-xN alloy on GaN(0001) substrate is carried out in the Nitrogen-rich flux conditions. A series of transient growth stages are identified from the initiation of the deposition. A significant effect of source beam-flux on the incorporation rate of Indium atoms is observed and measured. A correlation between the incorporation rate and the growth conditions (flux ratio and growth temperature) is revealed by the dependence of the growth-rate of the film on beam fluxes. A mathematic model is then suggested to explain the effect, through which the measured results indicating a surface diffusing and trapping process is indicated. Unexpected behavior of the lattice-parameter evolution of the growth front during deposition is also observed, indicating a complex strain-relaxation process of the epilayers. For three-dimensional (3D) topological insulator of Bi2Se3, growths are attempted on various substrate surfaces, including clean Si(111)-(7x7), Hydrogen terminated Si(111), Bismuth induced Si(111) reconstructed surfaces, GaN(0001), and some selenide "psudo-substrates." The specific formation process of this quintuple-layered material in MBE is investigated, from which the Van der Waals epitaxy growth characteristics inherent to deposition of Bi2Se3 is determined, and the mechanism of the "two-step growth" technique for this material is further clarified. Among the various substrates, those that are inert to chemical reaction with Bi/Se are important for the growth. The epilayers' lattice-misfit with the substrate is also a crucial factor to the structural quality of the Bi2Se3 epifilms, such as the defects density and the single-crystalline domain size. The effect of a vicinal substrate on suppressing the twin-defects in film is also addressed. Using a suitable substrate and adapting an optimal condition, ultra-thin films of Bi2Se3 with a superior structural quality have been achieved. Multilayered Bi2Se3 structures with ZnSe and In2Se3 spacers are attempted. Finally the high-quality superlattices of Bi2Se3/In2Se3 are successfully synthesized. The hetero-interfaces in the superlattice structure of Bi2Se3/In2Se3 are sharp, and the individual layers are uniform with thicknesses being strictly controlled. The behaviors of strain evolution during the hetero-growth process are finally investigated. An exponential relaxation of misfit strain is observed. And the correlation between the residual strain and the starting surface in the initial growth stage is also identified. DOI: 10.5353/th_b4716348 Subjects: Aluminum alloys Indium alloys Bismuth compounds Selenium compounds Thin films Heterostructures Molecular beam epitaxy
Polarization Dependent Photocurrents in Thin Films of the Topological Insulator Bi2Se3
Author: Claudia M. LauPublisher:
ISBN:
Category :
Languages : en
Pages : 68
Book Description
Topological insulators are a new class of three-dimensional quantum materials whose interior or bulk is an insulator but whose surface is a conductor. Bi2Se3 is a prototypical topological insulator that physicists at MIT are manufacturing and studying. Various interesting properties of the topological insulator include the flow of pure spin currents and topological protection. Pure spin current, distinct from electric current, is a net flow of spin without a net flow of charge. Recent research at MIT has revealed that shining circularly polarized laser light on a topological insulator turns its surface's pure spin current into a spin-polarized electrical current. The band structure of the bulk of a topological insulator resembles that of an ordinary insulator; the conduction band and valence band are separated, with the Fermi level falling between them. However, for Bi2Se3, the conducting surface's dispersion relation can be modeled by a Dirac cone, which crosses the Fermi level. Electrons with opposing spins reside on opposite sides of the Dirac cone. Illuminating a topological insulator with either left or right circularly polarized light depopulates one side of the Dirac cone, leaving on the other side the desired spin-polarized electrical current. In the experiment performed for this thesis, thin films of Bi2Se3 were grown on substrates of sapphire via molecular beam epitaxy (MBE). Electrical devices on a micron scale were then fabricated on the thin film surface and used to measure surface currents. Steps of this experiment included characterizing the surface quality of a sapphire substrate using atomic force microscopy (AFM), making electrical devices with Bi2Se3 via the processes of optical lithography, ion milling, and electron beam metal deposition. Photocurrents across these electrical devices were induced by the manipulation of optics and lasers and measured using low noise electronics. Experimental results revealed that it was indeed possible to induce spin-polarized electrical currents on thin films of MBE grown Bi2Se3. The desired photocurrent was observed when the laser beam spot size was enlargened to illuminate the entirety of the Bi2Se3 device simultaneously. These results were not replicable when the laser was more tightly focused onto a smaller area. Scanning the focused laser beam across the Bi2Se3 confirmed that different photocurrents were being induced at different points; these results led us to the conclude that there was something inhomogenous about our device. The reason behind this device inhomogeneity is still under investigation.
Molecular Beam Epitaxy of Topological Insulator Thin Films
Author: Jörn KampmeierTopological Insulators
Author: Publisher: Elsevier
ISBN: 0444633189
Category : Science
Languages : en
Pages : 349
Book Description
Topological Insulators, volume six in the Contemporary Concepts of Condensed Matter Series, describes the recent revolution in condensed matter physics that occurred in our understanding of crystalline solids. The book chronicles the work done worldwide that led to these discoveries and provides the reader with a comprehensive overview of the field. Starting in 2004, theorists began to explore the effect of topology on the physics of band insulators, a field previously considered well understood. However, the inclusion of topology brings key new elements into this old field. Whereas it was thought that all band insulators are essentially equivalent, the new theory predicts two distinct classes of band insulators in two spatial dimensions and 16 classes in three dimensions. These "topological" insulators exhibit a host of unusual physical properties, including topologically protected gapless surface states and exotic electromagnetic response, previously thought impossible in such systems. Within a short time, this new state of quantum matter, topological insulators, has been discovered experimentally both in 2D thin film structures and in 3D crystals and alloys. It appears that topological insulators are quite common in nature, and there are dozens of confirmed substances that exhibit this behavior. Theoretical and experimental studies of these materials are ongoing with the goal of attaining the fundamental understanding and exploiting them in future practical applications. - Usable as a textbook for graduate students and as a reference resource for professionals - Includes the most recent discoveries and visions for future technological applications - All authors are prominent in the field
Advanced Topological Insulators
Author: Huixia LuoPublisher: John Wiley & Sons
ISBN: 1119407338
Category : Technology & Engineering
Languages : en
Pages : 416
Book Description
This book is the first pedagogical synthesis of the field of topological insulators and superconductors, one of the most exciting areas of research in condensed matter physics. Presenting the latest developments, while providing all the calculations necessary for a self-contained and complete description of the discipline, it is ideal for researchers and graduate students preparing to work in this area, and it will be an essential reference both within and outside the classroom. The book begins with the fundamental description on the topological phases of matter such as one, two- and three-dimensional topological insulators, and methods and tools for topological material's investigations, topological insulators for advanced optoelectronic devices, topological superconductors, saturable absorber and in plasmonic devices. Advanced Topological Insulators provides researchers and graduate students with the physical understanding and mathematical tools needed to embark on research in this rapidly evolving field.