Download or read book Valley Dynamics and Excitonic Properties in Monolayer Transition Metal Dichalcogenides written by Louis Bouet and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The possibility of isolating transition metal dichalcogenide monolayers by simple experimental means has been demonstrated in 2005, by the same technique used for graphene. This has sparked extremely diverse and active research by material scientists, physicists and chemists on these perfectly two-dimensional (2D) materials. Their physical properties inmonolayer formare appealing both fromthe point of view of fundamental science and for potential applications. Transition metal dichalcogenidemonolayers such asMoS2 have a direct optical bandgap in the visible and show strong absorption of the order of 10% per monolayer. For transistors based on single atomic layers, the presence of a gap allows to obtain high on/off ratios.In addition to potential applications in electronics and opto-electronics these 2D materials allow manipulating a new degree of freedom of electrons, in addition to the spin and the charge : Inversion symmetry breaking in addition to the strong spin-orbit coupling result in very original optical selection rules. The direct bandgap is situated at two non-equivalent valleys in k-space, K+ and K-. Using a specific laser polarization, carriers can be initialized either in the K+ or K- valley, allowing manipulating the valley index of the electronic states. This opens up an emerging research field termed "valleytronics". The present manuscript contains a set of experiments allowing understanding and characterizing the optoelectronic properties of these new materials. The first chapter is dedicated to the presentation of the scientific context. The original optical and electronic properties of monolayer transition metal dichalcogenides are demonstrated using a simple theoreticalmodel. The second chapter presents details of the samples and the experimental setup. Chapters 3 to 6 present details of the experiments carried out and the results obtained. We verify experimentally the optical selection rules. We identify the different emission peaks in the monolayer materials MoS2, WSe2 and MoSe2. In time resolved photoluminescence measurements we study the dynamics of photo-generated carriersand their polarization. An important part of this study is dedicated to experimental investigations of the properties of excitons, Coulomb bound electron-hole pairs. In the final experimental chapter, magneto-Photoluminescence allows us to probe the electronic band structure and to lift the valley degeneracy.

Download or read book Two Dimensional Transition Metal Dichalcogenides written by Alexander V. Kolobov and published by Springer. This book was released on 2016-07-26 with total page 545 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book summarizes the current status of theoretical and experimental progress in 2 dimensional graphene-like monolayers and few-layers of transition metal dichalcogenides (TMDCs). Semiconducting monolayer TMDCs, due to the presence of a direct gap, significantly extend the potential of low-dimensional nanomaterials for applications in nanoelectronics and nano-optoelectronics as well as flexible nano-electronics with unprecedented possibilities to control the gap by external stimuli. Strong quantum confinement results in extremely high exciton binding energies which forms an interesting platform for both fundamental studies and device applications. Breaking of spatial inversion symmetry in monolayers results in strong spin-valley coupling potentially leading to their use in valleytronics. Starting with the basic chemistry of transition metals, the reader is introduced to the rich field of transition metal dichalcogenides. After a chapter on three dimensional crystals and a description of top-down and bottom-up fabrication methods of few-layer and single layer structures, the fascinating world of two-dimensional TMDCs structures is presented with their unique atomic, electronic, and magnetic properties. The book covers in detail particular features associated with decreased dimensionality such as stability and phase-transitions in monolayers, the appearance of a direct gap, large binding energy of 2D excitons and trions and their dynamics, Raman scattering associated with decreased dimensionality, extraordinarily strong light-matter interaction, layer-dependent photoluminescence properties, new physics associated with the destruction of the spatial inversion symmetry of the bulk phase, spin-orbit and spin-valley couplings. The book concludes with chapters on engineered heterostructures and device applications such as a monolayer MoS2 transistor. Considering the explosive interest in physics and applications of two-dimensional materials, this book is a valuable source of information for material scientists and engineers working in the field as well as for the graduate students majoring in materials science.

Download or read book Exciton and Valley Properties in Atomically Thin Semiconductors and Heterostructures written by Kha Xuan Tran and published by . This book was released on 2019 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two dimensional van der Waals (vdW) materials recently emerged as promising candidates for optoelectronic, photonic, and valleytronic applications. Monolayer transition metal dichalcogenides (TMD) are semiconductors with a band gap in the visible frequency range of the electromagnetic spectrum. Their unique properties include evolution from indirect band gap in bulk materials to direct band gap in monolayers, large exciton binding energy (few hundred meV), large absorption per monolayer (about 10%), strong spin-orbit coupling, and spin-valley locking. Moreover, two or more TMD monolayers can be stacked on top of one another to create vdW heterostructures with exciting new properties. Optical properties of semiconductors near the band gap are often dominated by the fundamental optical excitation: the exciton (Coulomb-bound electron-hole pair). Excitons in TMD monolayers (intralayer exciton) exhibit a large binding energy and a very short lifetime. The excitons in TMD monolayers are formed at the boundary of the Brillouin zone at the K and K' points. The time-reversal symmetry dictates that spins are oriented with opposite directions, leading to distinct optical selection rules for the excitons at these two valleys, a property known as the spin-valley locking. Valley polarization is often characterized by circularly polarized photoluminescence (PL). We show that the degree of valley polarization in a WSe2 monolayer depends on the degree of disorder evaluated by the Stokes shift between the PL and absorption spectra. Intrinsic valley dynamics associated with different optical resonances can only be evaluated using resonant nonlinear optical spectroscopy. We discovered exceptionally long-lived intra-valley trions in WSe2 monolayers using two-color, polarization resolved pump-probe spectroscopy. A different type of excitons (interlayer excitons) may rapidly form in TMD heterostructures with a type-II band alignment. Because of the spatial indirect nature, interlayer excitons have a much longer lifetime, which is tunable by the twist angle between the two layers. Especially, we discover that multiple interlayer excitons formed in a small twist angle heterobilayer exhibit alternating circular polarization - a feature uniquely pointing to Moiré potential as the origin. We assign these peaks to the ground state and excited state excitons localized in a Moiré potential and explain how the spatial variation of optical selection rule within the moiré superlattice can give rise to multiple peaks with alternative circular polarization. The twist angle dependence, recombination dynamics, and temperature dependence of these interlayer exciton resonances all agree with the localized exciton picture. Our results suggest the feasibility of engineering artificial excitonic crystal using vdW heterostructures for nanophotonics and quantum information applications

Download or read book Quantum Coherent Dynamics of Excitons and Valley Pseudospins in Atomically Thin Semiconductors written by Kai Hao (Ph. D.) and published by . This book was released on 2018 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt: Monolayer transition metal dichalcogenides (TMDCs) are new emerging van der Waals materials. Several TMDC materials go through with a transition from indirect to direct gap semiconductors when reduced to monolayer thickness limit with emission in the visible to near-infrared range, making them attractive materials for optoelectronic applications. Their near-gap optical properties are dominant by excitons (bound electron-hole pairs), charged excitons (known as trions) or higher order bound states (e.g., neutral and charged biexcitons). In this dissertation, we explored the quantum coherent dynamics of exciton, trions and their associated valley index using a powerful ultrafast spectroscopy tool known as the two-dimensional coherent spectroscopy (2DCS). We investigated the underlying mechanisms that determined the valley coherence associated with excitons and trions. In monolayer TMDCs, there are two inequivalent K and K' points in momentum space, where the band extrema are located and the excitons are formed. The excitonic states in the two valleys are selectively coupled to light with opposite helicity. This valley contrasting optical selection rules allow one to address and manipulate the valley index readily, a unique property and advantage of TMDC materials for valleytronic applications. The valley coherence can be quantitatively evaluated in polarization resolved zero-quantum 2D spectra. We found that the exciton valley coherence is limited by the electron-hole exchange interaction in the system. In contrast, for the charged exciton (trion) states, where the inter-valley scattering is suppressed, it is the intra-valley pure dephasing limits the inter-valley coherence time. These results provide the insight of valley coherence dynamics in monolayer TMDCs and suggest possible approaches to improve the valley coherence time. Next, we investigate the coherence coupling between excitons and trions created in one valley. The trions are charged quasiparticles which contribute to the charge transport directly. Thus, the coupling between exciton and trion states can significantly influent the interpretation of transport measurements. We demonstrate that these two types of quasiparticles are coherently coupled to each other by the observation of the quantum beating of the cross-diagonal peaks in one-quantum 2D spectra. The coherence time between them can be extracted by monitoring the amplitude decay of the beating signal. We found that the coherent coupling dephasing rate between the exciton and trion equals to the sum of the exciton and trion dephasing rate, indicating uncorrelated dephasing process for excitons and trions. At longer time scale, the phonon-assisted energy transfer couples the two states incoherently. Finally, we studied the higher order correlated states in monolayer TMDCs. We used polarization resolved 2DCS to reveal bounded inter-valley neutral biexcitons and charged biexcitons as new peaks which spectrally shifted in 2D spectra. The binding energies of these biexcitons are ∼20 and ∼5 meV respectively. Unlike linear optical spectroscopy studies, the 2D spectra separate the different quantum pathways. Hence, these spectra provide unambiguous evidence of the biexciton states. The extracted binding energy of the biexciton states agrees with theoretical calculation and resolves controversies in the literature. Biexciton formation is important for applications such as lasers and generations of entangled photon pairs.

Download or read book SPIN AND VALLEY DEPENDENT EXCITONS IN ATOMICALLY THIN TRANSITION METAL DICHALCOGENIDES written by Zefang Wang and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Transition metal dichalcogenides (TMDCs) exhibit remarkable electronic properties when thinned down to the monolayer limit. Among them, atomically thin semiconducting TMDCs, such as MoS2, MoSe2, WSe2, etc., attract board interest due to their unique electronic and optoelectronic properties. Electrons in 2D TMDCs acquire not only spin but also valley degree of freedom, and the spin and valley are coupled due to broken inversion symmetry and strong spin-orbit coupling. Opposite valleys are associated with opposite Berry curvature, giving rise to interesting valley physics and valleytronic applications. Another unique aspect of atomically thin TMDCs is strong excitonic effect. Owing to quantum confinement, monolayer semiconducting TMDCs become direct bandgap semiconductor in contrast to indirect bandgap in their bulk counterparts, and the excitonic effect gets greatly boosted due to the reduced dimensionality. Strong excitonic effect gives rise to strong light-matter interaction, making optical spectroscopy a powerful tool to access intriguing spin and valley properties of 2D TMDCs.In this dissertation, we explore the spin and valley dependent properties of monolayer TMDCs with optical and electrical transport techniques with high quality devices. In the first part, we study the electronic band structure in K/K valleys of Brillouin zone of monolayer WSe2 and MoSe2 by optical reflection and photoluminescence spectroscopy on dual gate field-effect transistors. Our experiment reveals the distinct spin polarization in the conduction band of these compounds by a systematic study of the doping dependence of A and B excitonic resonances. We obtained conduction band spin splitting delta_c is approximately 40meV for WSe2 and delta_c is approximately -30meV for MoSe2, which are in good agreements with first principle calculations.In the second part, we examined Landau level structure in monolayer WSe2 at the presence of out-of-plane magnetic field. It is proposed by theory that the Berry curvature in valley degree of freedom together with strong spin-orbit interaction can generate unconventional Landau levels under a perpendicular magnetic field. We applied handedness-resolved optical reflection spectroscopy and observed fully valley- and spin-polarized LLs in high quality WSe2 monolayer field-effect transistor and therefore derived LL structure. We also measured a sizeable doping-induced mass renormalization driven by strong Coulomb interactions.In the third part, we continued to explore the strong Coulomb interactions by studying the valley magnetic response in 2D TMDCs. We measured doping dependency of the valley Zeeman splitting of the charged exciton emission in monolayer WSe2 under an out-of-plane magnetic field. A nonlinear valley Zeeman effect correlated with an over fourfold enhancement in the g-factor, is observed. This enhancement occurs when Fermi level crosses the spin-split upper conduction band, corresponding to a change of spin-valley degeneracy from two to four, and can be understood as a consequence of a sharp increase in the exchange interaction when the number of electron species doubles. This interaction-enhanced valley magnetic response suggests 2D TMDCs as a new platform for exploring strongly interacting electron system with multiple internal degrees of freedom.In the final part, a study on interlayer exciton in bilayer WSe2 is presented. Interlayer excitons are sought for creating high exciton density and optoelectronic applications due to their long lifetime. Here we demonstrate highly tunable interlayer excitons by an out-of-plane electric field in bilayer WSe2. Continuous tuning of the exciton dipole from negative to positive orientation has been achieved and a large linear field-induced redshift up to ~100meV has been observed in exciton resonance energy. The Stark effect is accompanied by an enhancement of exciton lifetime by more than two orders of magnitude to >20ns. The exciton density as high as 1.210^11 cm^(2) can be created by moderate continuous-wave optical pumping. Our result has paved the way for realization of degenerate exciton gases in 2D TMDCs.

Download or read book Two dimensional Coherent Spectroscopy of Monolayer Transition Metal Dichalcogenides written by Chandriker Kavir Dass and published by . This book was released on 2015 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two-dimensional semiconductors have long been studied for their unique optical and electronic properties, but with the work of Novoselov and Geim on van der Waals materials, two-dimensional semiconductors have seen a surge of renewed interest. This dissertation focuses on monolayer transition metal dichalcogenides (TMDCs), a class of two-dimensional materials that can easily be fabricated by mechanical exfoliation, much like graphene. In their bulk form, these materials have indirect band gaps, but transition to direct gap semiconductors in the monolayer limit. The band-edge optical response of TMDCs, like WSe2 and MoS2, is dominated by exciton absorption occurring at the ±K-points of the Brillouin zone. Because of the unique electronic structure of these materials, these two points form distinct valleys in the band structure which can be exploited to produce valley polarization. Exciton quantum dynamics are characterized by two fundamental parameters, one of which is the dephasing rate, [gamma], which describes quantum dissipation arising from the interaction of the excitons with their environment (i.e. other excitons, impurities, etc...). This dissertation focuses on measuring the fundamental property of dephasing time (which is inversely proportional to the dephasing rate and homogeneous linewidth) in monolayer WSe2 through the use of two-dimensional coherent spectroscopy. Our measurements have revealed a homogeneous linewidth consistent with dephasing times in the sub-picosecond regime. We also characterize the role of exciton-exciton and exciton-phonon interactions, on the homogeneous linewidth, through excitation density and temperature dependent studies. These studies have revealed strong many-body effects and nonradiative population relaxation as the primary dephasing mechanisms. Microscopic calculations show that in perfect crystalline samples of monolayer TMDCs, the radiative lifetimes are also in the sub-picosecond regime due to the large oscillator strengths inherent in these materials. This result is consistent with the short dephasing times found experimentally.

Download or read book Quantum Theory of the Optical and Electronic Properties of Semiconductors written by Hartmut Haug and published by World Scientific. This book was released on 1994 with total page 496 pages. Available in PDF, EPUB and Kindle. Book excerpt: This textbook presents the basic elements needed to understand and engage in research in semiconductor physics. It deals with elementary excitations in bulk and low-dimensional semiconductors, including quantum wells, quantum wires and quantum dots. The basic principles underlying optical nonlinearities are developed, including excitonic and many-body plasma effects. The fundamentals of optical bistability, semiconductor lasers, femtosecond excitation, optical Stark effect, semiconductor photon echo, magneto-optic effects, as well as bulk and quantum-confined Franz-Keldysh effects are covered. The material is presented in sufficient detail for graduate students and researchers who have a general background in quantum mechanics.

Download or read book Two Dimensional Transition Metal Dichalcogenides written by Narayanasamy Sabari Arul and published by Springer. This book was released on 2019-07-30 with total page 355 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents advanced synthesis techniques adopted to fabricate two-dimensional (2D) transition metal dichalcogenides (TMDs) materials with its enhanced properties towards their utilization in various applications such as, energy storage devices, photovoltaics, electrocatalysis, electronic devices, photocatalysts, sensing and biomedical applications. It provides detailed coverage on everything from the synthesis and properties to the applications and future prospects of research in 2D TMD nanomaterials.

Download or read book Probing Excitonic Mechanics in Suspended and Strained Transition Metal Dichalcogenides Monolayers written by Hongchao Xie and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the past decade, the interest in two-dimensional (2D) materials, especially for atomically thin transition metal dichalcogenide (TMD) semiconductors, had dramatically thrived for both fundamental science and practical applications. The reduced dielectric screening in 2D mainly attributes to the strong excitonic effect in atomically thin TMD semiconductors. This pronounced exciton feature can maintain at room temperature, which indicates strong light-matter interaction and possible optoelectronic application using monolayer semiconductors. Meanwhile, the absence of inversion symmetry and out-of-plane mirror symmetry jointly endows carriers in monolayer TMDs with a new valley degree of freedom (DOF). Namely, in hexagonally-arranged lattice of 2D materials, electrons that residing at band edges of K and K valleys can carry opposite valley magnetic moments and Berry curvatures, which allows the further control of valley-indexed carriers with polarized light, electrical and magnetic fields. Besides, the large strain sustainability of monolayer TMDs gives rise to mechanically tunable band gap with 70 meV redshift per 1% strain up to recorded 10% applied strain. Thus, the interaction of macroscopic mechanical means with valley electrons makes monolayer TMD semiconductor a promising platform to implement novel valley-controlled mechanical devices. This motivates the experimental studies demonstrated in this dissertation.In this dissertation, we investigate the valley contrasting coupling between optoelectronic carriers (exciton & flowing electrons) and mechanics in a monolayer TMD semiconductor. In the first parts (Chapter 1&2), I will present emerging properties of TMD monolayers and discuss interesting physics that can study after suspending or straining these atomically thin materials. The fabrication and measurement of typical TMD suspended devices will also be demonstrated in details. In the secondary part (Chapter 3), we demonstrate robust exciton bistability by continuous-wave optical excitation in a suspended monolayer WSe2 at a much lower intensity level of 103 W/cm2. The observed bistability is originated from a photothermal mechanism, which can provide both optical nonlinearity and internal passive feedback in a simple cavity-less structure. This is supported by detailed excitation wavelength and power dependence studies of the sample reflectance, as well as by numerical simulation including the temperature-dependent optical response of monolayer WSe2. Furthermore, under a finite magnetic field, the bistability becomes valley dependent and controllable not only by light intensity but also by light helicity due to the exciton valley Zeeman effect, which open up an exciting opportunity in controlling light with light using monolayer materials.In the following part (Chapter 4), we report the observation of exciton-optomechanical coupling in a suspended monolayer MoSe2 mechanical resonator. In particular, we have observed light-induced damping and anti-damping of mechanical vibrations and modulation of the mechanical spring constant by moderate optical pumping near the exciton resonance with variable detuning. The observed exciton-optomechanical coupling strength is also highly gate-tunable. Our observations can be fully explained by a model based on photothermal backaction and gate-induced mirror symmetry breaking in the device structure. The observation of gate-tunable exciton-optomechanical coupling in a monolayer semiconductor may find novel applications in nanoelectromechanical systems (NEMS) and in exciton-optomechanics.In the last part of this dissertation (Chapter 5), we present the study of magnetization purely originated from the valley DOF in strained MoS2 monolayers. By breaking the three-fold rotational symmetry in single-layer MoS2 via a uniaxial stress, we have demonstrated the pure electrical generation of valley magnetization in this material, and its direct imaging by Kerr rotation microscopy. The observed out-of-plane magnetization is independent of in-plane magnetic field, linearly proportional to the in-plane current density, and optimized when the current is orthogonal to the strain-induced piezoelectric field. These results are fully consistent with a theoretical model of valley magnetoelectricity driven by Berry curvature effects. Furthermore, the effect persists at room temperature, opening possibilities for practical valleytronic devices.

Download or read book Coherent Light Matter Interactions in Monolayer Transition Metal Dichalcogenides written by Edbert Jarvis Sie and published by Springer. This book was released on 2017-11-11 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents optical methods to split the energy levels of electronic valleys in transition-metal dichalcogenides (TMDs) by means of coherent light-matter interactions. The electronic valleys found in monolayer TMDs such as MoS2, WS2, and WSe2 are among the many novel properties exhibited by semiconductors when thinned down to a few atomic layers, and have have been proposed as a new way to carry information in next generation devices (so-called valleytronics). These valleys are, however, normally locked in the same energy level, which limits their potential use for applications. The author describes experiments performed with a pump-probe technique using transient absorption spectroscopy on MoS2 and WS2. It is demonstrated that hybridizing the electronic valleys with light allows one to optically tune their energy levels in a controllable valley-selective manner. In particular, by using off-resonance circularly polarized light at small detuning, one can tune the energy level of one valley through the optical Stark effect. Also presented within are observations, at larger detuning, of a separate contribution from the so-called Bloch--Siegert effect, a delicate phenomenon that has eluded direct observation in solids. The two effects obey opposite selection rules, enabling one to separate the two effects at two different valleys.

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.

Download or read book Trion Formation Dynamics in Monolayer Transition Metal Dichalcogenides written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Here, we report charged exciton (trion) formation dynamics in doped monolayer transition metal dichalcogenides, specifically molybdenum diselenide (MoSe2), using resonant two-color pump-probe spectroscopy. When resonantly pumping the exciton transition, trions are generated on a picosecond time scale through exciton-electron interaction. As the pump energy is tuned from the high energy to low energy side of the inhomogeneously broadened exciton resonance, the trion formation time increases by ~50%. This feature can be explained by the existence of both localized and delocalized excitons in a disordered potential and suggests the existence of an exciton mobility edge in transition metal dichalcogenides.

Download or read book 2D Materials written by Phaedon Avouris and published by Cambridge University Press. This book was released on 2017-06-29 with total page 521 pages. Available in PDF, EPUB and Kindle. Book excerpt: Learn about the most recent advances in 2D materials with this comprehensive and accessible text. Providing all the necessary materials science and physics background, leading experts discuss the fundamental properties of a wide range of 2D materials, and their potential applications in electronic, optoelectronic and photonic devices. Several important classes of materials are covered, from more established ones such as graphene, hexagonal boron nitride, and transition metal dichalcogenides, to new and emerging materials such as black phosphorus, silicene, and germanene. Readers will gain an in-depth understanding of the electronic structure and optical, thermal, mechanical, vibrational, spin and plasmonic properties of each material, as well as the different techniques that can be used for their synthesis. Presenting a unified perspective on 2D materials, this is an excellent resource for graduate students, researchers and practitioners working in nanotechnology, nanoelectronics, nanophotonics, condensed matter physics, and chemistry.

Download or read book Quantum Confined Excitons in 2 Dimensional Materials written by Carmen Palacios-Berraquero and published by Springer. This book was released on 2018-11-02 with total page 125 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the first established experimental results of an emergent field: 2-dimensional materials as platforms for quantum technologies, specifically through the optics of quantum-confined excitons. It also provides an extensive review of the literature from a number of disciplines that informed the research, and introduces the materials of focus – 2d Transition Metal Dichalcogenides (2d-TMDs) – in detail, discussing electronic and chemical structure, excitonic behaviour and response to strain. This is followed by a brief overview of quantum information technologies, including concepts such as single-photon sources and quantum networks. The methods chapter addresses quantum optics techniques and 2d-material processing, while the results section shows the development of a method to deterministically create quantum dots (QDs) in the 2d-TMDs, which can trap single-excitons; the fabrication of atomically thin quantum light-emitting diodes to induce all-electrical single-photon emission from the QDs, and lastly, the use of devices to controllably trap single-spins in the QDs –the first step towards their use as optically-addressable matter qubits.

Download or read book Semiconductors written by Martin I. Pech-Canul and published by Springer. This book was released on 2019-01-17 with total page 596 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a practical guide to optical, optoelectronic, and semiconductor materials and provides an overview of the topic from its fundamentals to cutting-edge processing routes to groundbreaking technologies for the most recent applications. The book details the characterization and properties of these materials. Chemical methods of synthesis are emphasized by the authors throughout the publication. Describes new materials and updates to older materials that exhibit optical, optoelectronic and semiconductor behaviors; Covers the structural and mechanical aspects of the optical, optoelectronic and semiconductor materials for meeting mechanical property and safety requirements; Includes discussion of the environmental and sustainability issues regarding optical, optoelectronic, and semiconductor materials, from processing to recycling.

Download or read book Defects in Two Dimensional Materials written by Rafik Addou and published by Elsevier. This book was released on 2022-02-14 with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt: Defects in Two-Dimensional Materials addresses the fundamental physics and chemistry of defects in 2D materials and their effects on physical, electrical and optical properties. The book explores 2D materials such as graphene, hexagonal boron nitride (h-BN) and transition metal dichalcogenides (TMD). This knowledge will enable scientists and engineers to tune 2D materials properties to meet specific application requirements. The book reviews the techniques to characterize 2D material defects and compares the defects present in the various 2D materials (e.g. graphene, h-BN, TMDs, phosphorene, silicene, etc.). As two-dimensional materials research and development is a fast-growing field that could lead to many industrial applications, the primary objective of this book is to review, discuss and present opportunities in controlling defects in these materials to improve device performance in general or use the defects in a controlled way for novel applications. Presents the theory, physics and chemistry of 2D materials Catalogues defects of 2D materials and their impacts on materials properties and performance Reviews methods to characterize, control and engineer defects in 2D materials

Download or read book Condensed Matter in a Nutshell written by Gerald D. Mahan and published by Princeton University Press. This book was released on 2011 with total page 592 pages. Available in PDF, EPUB and Kindle. Book excerpt: An introduction to the area of condensed matter in a nutshell. This textbook covers the standard topics, including crystal structures, energy bands, phonons, optical properties, ferroelectricity, superconductivity, and magnetism.