Modelling And Design Of Nanostructured Optoelec...
Theory, modelling, and computational methods for semiconductor materials and nanostructures is a topic of rapid growth and great international interest. A lot of the world-wide effort over the past 50 years in establishing the theoretical foundation of methodologies for calculations of structural, electronic, optical and transport (electrical and thermal) properties of semiconductor nanostructured materials [1-61] are now coming to fruition [62-67].
Modelling and Design of Nanostructured Optoelec...
Among the many empirical methods available, the multi-band k.p (k.p), empirical tight binding (ETB), and empirical pseudopotential (EPM) methods are proving invaluable in the design and modelling of modern optoelectronic devices and semiconductor nanostructures.
Electronic structure methods, such as multiband k.p, Empirical Tight Binding and Empirical Pseudopotential, coupled with empirical methods for the determination of the crystal structure (Valence Force Field, Bond Order Potentials) have recently seen much improvement in both the methodology, parameterizations and computational speed. The next step will certainly be that of condensing and interfacing all the individual efforts to produce tools that are of more general use to the wider community. It is therefore now very timely to devote two closely coupled CECAM Workshops to the use of empirical methods for semiconductor nanostructure design and modelling, with the first (ACAM) Workshop focused primarily on computational/technical issues, numerical implementations and parametrisation strategies, followed immediately by the second (STFC Daresbury) Workshop highlighting the scientific issues and demands related to empirical nanostructure design and modelling.
Research Interests Thermal energy conversion, storage, and transport in nanostructured materials; thermoelectric power generation; thermal storage media; heat transfer, and phonon optics. Custom-design of colloidal nanoparticles, chemical precursors
Nanophotonics has emerged as a major technology and applications domain, exploiting the interaction of light-emitting and light-sensing nanostructured materials. These devices are lightweight, highly efficient, low on power consumption, and are cost effective to produce. The authors of this book have been involved in pioneering work in manufacturing photonic devices from carbon nanotube (CNT) nanowires and provide a series of practical guidelines for their design and manufacture, using processes such as nano-robotic manipulation and assembly methods. They also introduce the design and operational principles of opto-electrical sensing devices at the nano scale. Thermal annealing and packaging processes are also covered, as key elements in a scalable manufacturing process. Examples of applications of different nanowire based photonic devices are presented. These include applications in the fields of electronics (e.g. FET, CNT Schotty diode) and solar energy.
The aim of this Special Issue is to bring together original research and review articles concerning the issues arising in the synthesis, characterizations and application of low-dimensional and nanostructured materials. The Virtual Special Issue will serve as a point of reference for the design, synthesis and characterization of novel materials and devices and a platform for exchanging ideas to promote rigorous scientific research and practical design.
Currently, nanostructured surface research is slow and fragmented due to the use of trial-and-error design methods; these often rely on the knowledge and intuition of researchers. Nanostructured surface experiments require the precise selection of various fabrication parameters, such as the flow rate of various gases, ion etching time, chamber pressure, etc. Moreover, the fabrication process is time consuming: one step in such an experiment requires 16 hours of chemical vapor deposition.
Controlling the surface chemistry of nano building blocks and their interfaces with ligands is one of the outstanding challenges for the rational design of all-inorganic nanostructured solids. We carried out a combined theoretical and experimental study to characterize, at the atomistic level, buried interfaces in solids of InAs nanoparticles capped with Sn2S64- ligands. These prototypical nanocomposites are known for their promising transport properties and unusual negative photoconductivity. We found that inorganic ligands dissociate on InAs to form a surface passivation layer. A nanocomposite with unique electronic and transport properties is formed, that exhibits type II heterojunctions favourable for exciton dissociation. We identified how the matrix density, sulfur content and specific defects may be designed to attain desirable electronic and transport properties, and we explain the origin of the measured negative photoconductivity of the nanocrystalline solids.
3.054 Cellular Solids: Structure, Properties, Applications ()Not offered regularly; consult department(Subject meets with 3.36)Prereq: 3.013Units: 3-0-9Discusses processing and structure of cellular solids as they are created from polymers, metals, ceramics, glasses, and composites; derivation of models for the mechanical properties of honeycombs and foams; and how unique properties of honeycombs and foams are exploited in applications such as lightweight structural panels, energy absorption devices, and thermal insulation. Covers applications of cellular solids in medicine, such as increased fracture risk due to trabecular bone loss in patients with osteoporosis, the development of metal foam coatings for orthopedic implants, and designing porous scaffolds for tissue engineering that mimic the extracellular matrix. Includes modelling of cellular materials applied to natural materials and biomimicking. Offers a combination of online and in-person instruction. Students taking graduate version complete additional assignments.Staff
3.36 Cellular Solids: Structure, Properties, Applications ()Not offered regularly; consult department(Subject meets with 3.054)Prereq: 3.013 or permission of instructorUnits: 3-0-9Discusses processing and structure of cellular solids as they are created from polymers, metals, ceramics, glasses, and composites; derivation of models for the mechanical properties of honeycombs and foams; and how unique properties of honeycombs and foams are exploited in applications such as lightweight structural panels, energy absorption devices, and thermal insulation. Covers applications of cellular solids in medicine, such as increased fracture risk due to trabecular bone loss in patients with osteoporosis, the development of metal foam coatings for orthopedic implants, and designing porous scaffolds for tissue engineering that mimic the extracellular matrix. Includes modelling of cellular materials applied to natural materials and biomimicking. Offers a combination of online and in-person instruction. Students taking graduate version complete additional assignments.Staff
Topology Optimization based inverse design and numerical modelling of wave propagation phenomena and electromagnetism. WP3: Theory and Topology Optimization. In NanoPhoton, I work with Topology Optimization to design EDC structures and topological structures for a wide range of applications. To this end I research and develop novel topology optimization based tools and methods, working among others to integrate fabrication limitations and design robustness directly in the design procedure to facilitate the reliable fabrication of designs, hereby bridging the gap between numerical models and experiments
I am working on the design, fabrication and characterization of nanostructured device for optical signal processing applications. Currently, I am working on a new type of optical receiver that can be used for simple and cost effective detection of advanced modulation formats such as QPSK and 16-QAM.
During my PhD I will continue the research on state-of-the-art nanolasers in the III-V on Si integrated platform developed at the Quantum and Lasers Photonics Group at DTU. The work will involve modelling, design optimization, fabrication, and characterization of the nanolasers and focusses on improving the performance as well as gaining a deeper understanding of the underlying physics.
Abstract: Surfaces and interfaces are at the heart of modern-day technology, playing a central role in a variety of fields including sensing, energy conversion, and nano-electronics. Recent advancements in ab-initio methods, materials informatics, and computing power present us with an exciting opportunity to predictively discover and design materials surfaces and interfaces. In this talk, through the example of two-dimensional materials, I will show how ab-initio simulations, combined with multi-scale modeling techniques and genetic algorithms can be used to computationally discover, synthesize, and functionalize nanostructured surfaces. I will show how such studies can be performed in a high throughput fashion to create databases of surfaces and their properties; drastically reducing the time needed to invent new materials for surface sensitive applications. In this light, I will show how we have identified scores of robust and synthesizable materials' surfaces for photocatalysis.
Metamaterials are artificial media structured on the sub-wavelength scale. While conventional materials derive their electromagnetic characteristics from the properties of atoms and molecules - metamaterials enable us to design our own 'meta-molecules' and interactions between them and thus access new ground-breaking functionalities. Metamaterials are expected to have an impact across the entire range of technologies where electromagnetic radiation is used, and provide a flexible platform for modelling and mimicking fundamental physical effects as diverse as superconductivity and cosmology and for templating electromagnetic landscapes to facilitate observations of otherwise difficult to detect phenomena.We report an overview on our recent results on new phenomena in metamaterials underpinned by meta-molecular interactions. This will include results on light localization in metamaterial arrays, metamaterial "lasing spaser", quantum Purcell enhancement of luminescence and spectral mode collapse.Furthermore we will introduce a range of novel functionalities observed in nanostructured photonic metamaterials containing nonlinear and active media such as switchable chalcogenide glass, carbon nanotubes, graphene and semiconductor quantum dots. 041b061a72