Hold 1
Improving Nanomedicine Performance: Do Nanomedicine Nanomechanics Influence Biological Response?
Hussein Abukar Hussein, s164014, og Magnus Koreska Sass Kindberg, s163984
Vejleder: Andrew Urquhart, Nanotech
Resume:
Liposome molecules show prominent use in the future of nanomedicine, amongst others in the battle against cancer. In nanomedicine, things such as circulation and clearance time in the human body has major impact on the efficiency of drug delivery. Size and surface structure has shown to have an influence circulation time as well as the molecules' unfavorable interaction with proteins native to the body, enabling "flagging" for the immune system as well as disabling our molecules from fulfilling its purpose. In this project we would like to investigate whether the physical properties of liposomes vary from empty to liposomes loaded with doxorubicin (known as doxils), and if possible, how these interact in comparison to harder nano-carriers. During this project we will analyze the physical properties of loaded and unloaded liposomes with aid of dynamic light scattering, zeta potential, osmotic pressure, fluorescence and atomic force microscopy. If possible, we would like to compare our results to the physical properties of a harder nano carrier, such as gold.
Hold 2
Semiconductor-based quantum technologies
Kasper Hecht Alexander, s163985, Alexander Gerard Niels Kittel, s164010, og Marcus Fruelund Schmidt, s163986
Vejledere: Nika Akopian og Lorenzo Leandro, Fotonik
Resume:
In our physics project about semiconductor-based quantum technologies, we will be aiding a research group at DTU Photonics in constructing a new lab setup. Using a quantum dot as a single-photon source, our goal is to consistently lock the emission line’s wavelength to that of the D2 transition of isotopically pure rubidium, counteracting charge fluctuations near the quantum well or initial differences between the D2 line of Rb and our emitted PL line. To achieve this, we make use of Zeeman splitting by subjecting the excited quantum dot to a powerful magnetic field and leading the emitted photon through a Rb vapour cell working in super-100 Celsius. As such, the energy of the PL emission can be shifted and locked to that of the Rb D2 transition – and by making use of an algorithm to dynamically change the magnetic field, can be made insusceptible to nearby charge fluctuations. The result of all this is a single-photon source which consistently produces a photon of the same wavelength – that of the D2 Rb transition of about 780 nm.
Hold 3
Adjustable Self-regulating Microfluidic Circuits
Stefan Kei Akazawa, s153333, og Emil Visby Østergaard, s163995
Vejledere: Kaare Hartvig Jensen and Keunhwan Park, Fysik
Resume:
A fluid channel in which the flow rate to pressure relationship can be pre-designed, could have many valuable applications. A patient in need of a constant yet slow dose rate of medicine during the day, could have a small device, which with a small pressure could supply medicine to their body at a constant rate. A chemist, could have a liquid being added to a solvent, without maintenance, or worries of erratic changes in flow rate. This type of mechanism in which the flow to pressure relationship is so well defined, could be designed using a system of soft valves. Whereas a regular channel has a linear resistance (Rhyd = ∆P/Q), and therefore has some inherent limitations in flow design, a soft valve will have a flow-pressure relationship looking something like figure (1a). The non-linearity, can be purposed by coupling multiple soft valves together, in a ”flow circuit” to create a specialized rate pressure relationship. Such a system could be accustomed to fit many uses. The design of the valves will initially be a combination of flexible beams and a half sphere for breaking the flow inspired by (Park 2017), by use of 3d printing and soft, elastic PDMS material. A cross section of this design is shown in figure (1b). As the pressure on the system increases, the flow rate will increase and the valve will start to close making the hydraulic resistance larger. These two counteracting effects result in a nonlinear pressure-flow relationship. The initial challenge in valve production, is beam flexibility. The plastic of the 3d printer, will often be too stiff and brittle for the beam and in it’s stead the silicone PDMS material, will be tested. The theory in which, we will build the systems, is that any pressure flow function needed, could be described as a Fourier series of parallel coupled valves. While the projects primary focus is parallel valve systems, the possibilities of serial coupling implementation will also be investigated. Serial coupling has some added complexities compared to parallel, due to each valve flow being dependant on preceding and succeeding valves in it’s series. The first part of the project will be spent designing the soft valve and setting up a test system as modelled in figure (1c). When the valve design is finished, Navier-Stokes equation will be solved for the system using Lubrication theory, to the specific geometry of the valve. The end goal will be to have a theoretical model for the flow through a group of our own, easily reproducible designed soft valves.
Hold 4
Semiconductor quantum dots
Benjamin Falkenberg Gøtzsche, s163996, Frederik Ryberg Madsen, s164005, og Martin Voss, s163970
Vejledere: Jesper Mørk og Kristoffer Bitsch Joanesarson, Fotonik
Resume:
Dette projekt tager udgangspunkt i kvantemekanikkens teoretiske begreber og de praktiske land- vindinger det har medført inden for teknologi. Projektets titel omhandler kvanteprikker, altså en 3-dimensional afgrænsning af de kvantefænomener der opstår ved den veldokumenterede model kaldet ”partikel i en boks”, hvor der er tale om en partikel indfanget i en potentialebrønd opstået af grænseflader mellem 2 forskellige materialer med forskellige potentialer. Omfanget af det forudliggende arbejde omhandler en forståelse for denne simplificerede model, hvor den generelle teori vil blive inddraget og gennemgået for derefter at kunne implementeres til den egent- lige, 3-dimensionale model. Derudover vil der være en undersøgelse af, hvornår noget klassificerer sig som kvantemekanik, altså hvilke fysiske antagelser og afgrænsninger der skal være for at der egentligt er snak om fysiske fænomener i kvantiserede størrelser. Det er ingen overraskelse at der ligger en masse teori bag emnet. Indledningen af dette projekt vil derfor bestå i at undersøge, forstå og diskutere betydningen af disse kvantemekaniske teoremer og teorier. Det vides at kvanteprikkers egentlige beskrivelse står som en partiel differentialligning der hurtigt bliver meget kompleks og uoverskuelig, hvis den skulle løses analytisk - hvis det overhovedet er muligt at det kan løses analytisk. Derfor kan det være nyttigt at løse ligningerne numerisk ved simulering. Dette vil blive gjort i et væsentligt omfang i projektet, hvor programmet COMSOL med dets indbyggede model vil bruges til at undersøge fænomener og størrelser i et kvantepunkt placeret på et såkaldt wetting-layer. Når dette forløb er overstået og dokumenteret, vil teorien benyttes med de fundne løsninger til at bevæge os over til det mere praktiske, hvor en videnskab med kvanteprikker vil undersøges, som løsning til de problemer der måtte opstå. Dette kunne være indenfor laserteknologi, solceller eller andet. Dette vil forhåbentlig forene teori og praksis, og tydeligheden skulle gerne fremkomme af rap- porten, hvor der vil forekomme en progressiv rød tråd fra den basale beskrivelse af teori i én dimension, videre i tre dimensioner og fører til at reflektere over dens betydning i fysisk forstand, hvor det til sidst vil implementeres på en egentlig problemstilling.
Hold 5
Bestemmelse af metode til korrekt og stabil måling af temperatur i katalytiske μ-reaktorer
Kristine Børsting, s153299, og Bianca Laura Hansen, s163993
Vejledere: Robert Jensen og Peter Vesborg, Fysik
Resume:
I dette projekt undersøges det, hvorfor termometret i en μ-reaktor giver forkerte målinger. Termometret i μ- reaktoren er et RTD-termometer, som udnytter lineariteten mellem elektrisk modstand og temperatur for platin. Hypotesen for fejlmålingerne er fænomenet elektromigration. Hvorvidt målefejlene skyldes elektromigration undersøges igennem en række forsøg. Først fotograferes en række ny-fremstillede μ-reaktorer vha. elektronmikroskopi. Prøverne undersøges dels ved at opvarme dem med en strøm, der løber igennem opvarmningspanellerne i chippen igennem længere tid og dels via en temperaturkontrolleret ovn. Herefter fotograferes prøverne igen. Under opvarmningen i ovnen ønskes det også at lave en modstands-temperatur sammenhæng til at holde op mod den forventede sammenhæng for platin. Hvis der er store ændringer på strukturen i platintråden, kan det skyldes elektromigration. Næste trin er så at køre en række målinger ved forskellig probe-strøm med henblik på at prøve at finde en sammenhæng mellem denne strøm og hastigheden hvormed RTD’en tager skade. Baseret på disse resultater kan der lægges en videre plan. Dette vil gå ud på dels at prøve at gøre platin laget tykkere, dels at prøve om RTD’en er mere robust, hvis den opvarmes i vakuum frem for atmosfærisk luft. Hvis elektromigrations-hypotesen ikke kan forklare fejlmålingerne vil det også være oplagt at underøge, hvis temperaturfejlene kan skyldes en kemisk reaktion. Ved dette tænkes enten, at titan diffunderer op i platinet, eller at der er sket en oxidation af platinet.
Hold 6
Simulering af Metalliske nanopartikler
Paul Christian Dahl Sinding, s154033
Vejleder: Jakob Schiøtz, Fysik
Resume:
Visse metalliske nanopartikler har den egenskab, at de kan binde sig til et oxidsubstrat ved selv at udvide deres krystalstruktur. Denne effekt observeres, når nanopartiklen og substratet har tætliggende gitterkonstanter, som dog ikke er helt ens. I disse tilfælde er der en tendens til, at nanopartiklen frivilligt øger distancen mellem atomerne for at minimere deres energi. Dette resulterer i, at nanopartiklerne får samme gitterkonstant som substratet, og er bundet til det. Grundet nanopartiklernes størrelse (ca 1000 atomer) er det ikke hensigtsmæssigt at anvende DFT (Density Functional Theory) på problemet. I stedet må der konstrueres en række effektive-potentialer, der gennem simulation kan beskrive atomernes opførsel i substratet, i nanopartiklen, og i grænsefladen mellem de to. Det er disse potentialer og deres opførsel, dette fagprojekt beskæftiger sig med.
Hold 7
Detektion og analyse af aerosoler
Veronica Humlebæk Jensen, s163980, Narwan Kabir Noori, s164019, og Jonathan Friis Schouenborg, s162692
Vejleder: Kristian Mølhave, Nanotech
Resume:
Formålet med dette fagprojekt, er at karakterisere aerosoler ud fra deres størrelse, form og sammensætning. Aerosolerne opsamles på en membran vha. en Impactor, hvorefter de visualiseres med en SEM (Skanning Electron Microscope) . Selve aerosolerne på membranen analyseres ved brug af forskellige billedanalyse-metoder, hvortil der lægges fokus på: Thresholding, Otsu’s method samt Adaptive Thresholding Tecnique. Til slut sammenlignes metoderne og der vurderes, hvilken metode der giver de bedste resultater.
Hold 8
Plasma diffusion in a fusion powerplant
Johan Christian Ehlers, s153725, og David Bak Weimar, s163988
Vejledere: Jens Juul Rasmussen og Volker Naulin, Fysik
Resume:
Nuclear fusion power seems to be one of the best possibilities to create a clean energy source in the future. However, many technological challenges have to be overcome in order to create a stable fusion process. In the study of fusion power, plasma is a central topic since all relevant fusion processes take place in plasma. The understanding of plasma and how plasma behaves in magnetic confinement is therefore necessary to understand how to sustain fusion. This paper will examine some general features of diffusion of plasma and the influence on the plasma confined in a tokamak fusion reactor. The focus will mainly be on the collision-driven diffusion, which will be modelled using partial differential equations. In particular we will consider a non linear, one dimensional version of the continuity equation with a source term, which will be solved numerically in different settings in order to obtain knowledge about the plasma diffusion. To begin with the diffusion will be considered in one thermodynamic variable - namely the density - and we will investigate how diffusion influences the plasma profile in a cylindrical geometry. This model may be extended to a two field model involving the dynamics of both the density field and the temperature field. The two field model is essential since the collision frequency, which determines the diffusion coefficient, depends on both the density and the temperature. Finally the numerical solution will be compared to an analytic result to estimate the precision of the solutions.
Hold 9
Nano-fabrication of quantum photonic devices
Benjamin Lundgren Larsen, s164006, og Kristian Seegert, s162588
Vejledere: Nika Akopian og Daniel Chastanet, Fotonik
Resume:
The project will focus on manufacturing of nanowires for quantum photonic devices. The aim of the project is to establish optimal parameters for growing uniform nanowires. The nanowires will primarily consist of wurtzite (ZnS) with small zinc (Zn) segments. The atomically sharp interface between the wurtzite and zinc will create crystal phase quantum dots (due to the lower bandgap of Zn and a negative offset) that should have limited problems with material diffusion. Figuring out a method to create these nanowires will allow uniform devices with precisely controlled properties. Crystal quantum dots makes a promising candidate for quantum bit building blocks due to their potential use in quantum computing and cryptography. The production will take place in DTU Danchips cleanroom. And the required processes to fabricate nanowires will include a multitude of techniques like e-beam lithography, dry etching and SEM. the InP wafer will be patterned with e-beam lithography. InP nanowires will be grown, hereafter PECVD (plasma enhanced chemical vapour deposition) will be used to create the zinc blend. SEM (scanning electron microscopy) will be used to characterise the nanowires grown.
Hold 10
Experimental Characterization of photonic crystal nanolasers
Lau Morten Kaas, s164015, Emil Munksgaard Larsen, s165461, og Kristian Frellesen Nielsen, s164008
Vejledere: Yi Yu, Kristoffer S. Mathiesen og Jesper Mørk, Fotonik
Resume:
This project aims to experimentally investigate semiconductor nanolasers realised using the photonic crystal membrane platform. The photonic crystal has an active region consisting of semiconductor quantum dots, where various spontaneous and stimulated transistions occur, and providing a good photon confinement. The photonic crystal functions as a wavelength-scale cavity enabling the laser to obtain both a low threshold current and operation energy due to the extremely small size of the active region. The carrier and photon densities are important for describing the laser performance, so these quantities are obtained by numerical solution of the conventional semiconductor laser rate equations. The obtained numerical solutions to the rate equations will be compared and fitted to the experimental data, and especially threshold current and output energy will be investigated, as well as the spontaneous emission factor of the laser. The final part of the project is open as of yet, but may contain further experimental work on varying different parameters of the crystal or additional numerical investigations of the laser performance.
Hold 11
Energy Harvesting for Sensors
Emil Thomas Christoffersen, s163978, og Frederik Krogh Ohms, s164007
Vejleder: Astri Bjørnetun Haugen, Energy
Resume:
For small, low-power-consumption devices, batteries are currently the only pragmatic option. But batteries require replacing, which is not always practical. Harvesting ambient energy is a way to reduce the worlds need of disposable energy sources. The direct piezoelectric effect permits current to be created from mechanical displacement. This promises a sustainable and convenient solution for devices such as sensors, IoT and pacemakers. We will discuss the basic theory of piezoelectricity, focusing on electromechanics and operation mode. Afterwards we will outline the different possible setups for a PEH (piezoelectric energy harvester) and examine design parameters, such as resonance frequency, damping, bandwidth and proof mass. Finally, this will be used to create an understanding of how a PEH might be tailored to a specific application. Four setups will be constructed to best highlight how different design parameters impact power generation, at and away from the resonance frequency. The setups will be tested to determine their resonance frequency, bandwidth and their mechanical impendence. Furthermore, the power generation will be measured, as the final basis of the PEH’s energy harvesting capabilities. We will examine a real-world potential application of PEH technology, to power a sensor, and using the knowledge gained from our experiment we will design an appropriate PEH, which could sufficiently harvest energy from the ambient environment to power the device. We expect to find that a MFC (micro-fiber composite) PEH can meet the energy demands of devices such as sensors. Problems with the technology is largely space, price and efficiency where batteries generally outperform PEHs. PEHs have the advantage of being self-sustaining which makes them useful in certain, specific situations, such as long-lifetime sensors and medical implants.
Hold 12
Semiconductor-based quantum technologies
Nicolai Krumhardt Enggren, s163998, og Jeppe Mikkelsen Roulund, s164012
Vejleder: Lorenzo Leandro, Fotonik
Resume:
For creating a 100%-secure Quantum Network, single photon sources are essential since would prevent eavesdroppers from observing sent information undetected due to the no cloning theorem[1]. A nanowire quantum dot is a promising solution to the problem of generating single photons, because it, for example, offers a much higher photon extraction rate than quantum dots without waveguides[2, 3]. In this project we will consider two different approaches to constructing of a Mach-Zehnder interferometer; A fiber-based and a free-space setup. The decided setup will then be used for measuring the first and second order correlation function in nanowire quantum dots. For the measurement of the second order correlation we'll utilize the Hong-Ou-Mandel effect to determine the indistinguishability of the emitted photons[4]. These measurements are important for determining the quality of nanowire quantum dots as a single photon source because a second order correlation of g(2)(0) < 0.5 would only be possible in a quantum mechanical system such as a single photon source[5]. In the duration of the project we will evaluate the pros and cons of multiple experimental setups, taking in to consideration the needs of the lab. Afterwards we will finalize the setup design and buy the necessary equipment. This will allow us to build the final setup that we will use to measure on already available quantum dots.
Hold 13
Diffusion of dopants in nanostructured, black silicon for application in solar cells
Olga Solodovnikova, s163967, Andreas Raimund Stilling-Andersen, s163997
Vejledere: Beniamino Iandolo og Rasmus Schmidt Davidsen, Nanotech
Resume:
Black silicon (b-Si), i.e. silicon with an anisotropic nanostructured surface, is a promising new material for solar cells as its nanostructured surface makes it virtually unreflective, increasing the cell’s efficiency. The larger surface area of b-Si compared to normal Si causes an increase in surface charge carrier recombination, however this issue has been substantially reduced using an aluminum oxide passivation layer. We will produce b-Si using a ICP reactive ion process. Industrially, silicon cells consist of a p-type (boron doped) silicon substrate into which phosphorous is diffused, creating the p-n junction which allows the cell to function. The efficiency of the cell therefore also depends on the minority carrier concentration, which in turn depends on the doping concentration and quality. The nanostructured b-Si surface inhibits a uniform diffusion of the dopant compared to the flat Si surface used in normal cells. Our goal is therefore to investigate and optimize the diffusion of the dopants in b-Si to improve efficiency. The industrial standard of phosphorous diffusion on p-type silicon wafers is to use a liquid POCl3 source at a high temperature in order to deposit a phosphosilicate glass (PSG) layer followed by a drive-in oxidation step using O2/N2 to drive the dopants deeper into the silicon. We will therefore investigate the effect of the parameters of this process in order to optimize the diffusion of the dopants into the b-Si surface. Specifically, we will measure the sheet resistance and minority carrier lifetime as they affect the efficiency.
Hold 14
Chip fabrication for TEM enabling of electrochemical processes
Sofie Tidemand-Lichtenberg, s163968
Vejleder: Kristian Mølhave, Nanotech
Resume:
To enable studies of electrochemical processes in the TEM, one needs to fabricate a chip consisting of two elements, a top and a bottom chip, making it possible to examine liquids. The project is divided into two parts; fabrication and data processing. The first part of the project, takes place in the cleanroom, optimizing the different aspects of the fabrication process and the chips. Both the top and bottom chip consist of a double polished silicon wafer, with a silicon nitride film on both sides. A window in the nitride on the top side of the wafer is created. Afterwards the exposed silicon is etched down to the bottom layer of the nitride, creating a window in the wafer, with only the bottom layer of nitride film. On the top chip, a series of electrodes are deposited. These electrodes make it possible to implement different experiments and applications, e.g. electrodeposition, lithiation process in a nano battery, conductivity measurements etc. As mentioned earlier, the fabrication process will be optimized. Among other things, the photoresist, will be changed from a manually to an automatically applied resist. In addition, the mask is changed from a bight field to a dark field, and the thickness of the wafers are changed from 350 µm to 400 µm. In the second part of the project, the chips are used to examine the movement of particles in liquids. A liquid with, for example, gold particles are deposited between the bottom and the top chip, and inserted into the TEM using a holder designed for this particular purpose. A series of images are then taken within a short time interval. The images are later stacked in ImageJ, creating a film, making it possible to track the particles over time. The movement of the particles makes it possible to evaluate the diffusion constant, making it possible to examine whether the particles move in a Brownian motion or not. Finally the new chips and the measurements are combined, where the functionality of the new mask is tested, with a series of measurements of the electrokinetic movements of particles in a liquid, when an electrical voltage is applied.
Hold 15
Experimental characterization of photonic crystal nanolasers
Adam Kamakh Asaad, s163044, Mikkel Blumensaadt Brand, s163966, og Jacob Boelskift Maretti, s164018
Vejledere: Kristoffer S. Mathiesen, Thorsten Svend Rasmussen og Jesper Mørk, Fotonik
Resume:
In this report, the basic physical theory behind diode lasers is treated. How different parameters affect how the laser behaves theoretically will be described, and the rate-equations for diode lasers will be solved numerically by computer programming. This will be done for both steady and non-steady states conditions. Samples of optically pumped photonic crystal nanolasers fabricated in DTU’s cleanroom, Danchip will be studied. The different fabrication parameters will be studied to see how they affect the threshold current and the gain factor for the nanolasers. A small investigation of the fabrication theory might be done and combined with the laser theory trying to optimize how well the fabricated lasers perform in terms of threshold current and gain factor. The results from the lab will be analyzed and applied to the rate-equations, thus finding the beta factor; internal loss and gain factor. As our conclusion, we will propose a way to improve the performance of the laser to reduce the threshold current based on experimental results and simulations of the rate equations.
Hold 16
High-energy X-ray measurements of solution-state samples
Asmund Kjellegaard Ottesen, s153285, og Dirk Warm, s163999
Vejledere: Kristoffer Haldrup og Jan Kehres, Fysik
Resume:
X-ray diffraction is a great way of measuring the atomic and molecular structure of crystals and has led to a better understanding of chemical bonds. But the synchrotron and X-ray laser are both expensive and often far away which makes it difficult to make experiments. With this project we want to characterize a new setup of X-ray diffractometers and investigate how the instrument functions. What makes this new setup unique is that it detects the X-ray photons by pixel at multiple angles at once, rather than having a single detector making a series of measurements at a different angles. So this high energy diffractometer makes it possible to have much faster experiments. With diffraction on a sample, a scattering pattern can be constructed be measuring the angles and intensities of the diffracted beams. This information is directly related to the three-dimensional view of the structure. When we have characterized the setup and found the best experimental parameters, we can then investigate the structure of a liquid. First we want to determine the structure of a known reference, in this case water. If possible we can then measure the reference with a solvent and compare the results. This will reveal the solvents molecular structure.
Hold 17
Crystalgrowth of magnetic nanoparticles
Mathias Hoeg Boisen, s164000, Frederik Laust Durhuus, s163969, og Lau Halkier Wandall, s163987
Vejledere: Cathrine Frandsen, Mathias Kure og Marco Beleggia, Fysik
Resume:
The main purpose of the project is to study how magnetic nanoparticles aggregate into clusters, driven by magnetic interactions. This is done through the simulation of the dynamic evolution of uniformly magnetized spheres distributed with initial arbitrary positions and orientations. The particles are treated as classical dipoles, interacting through torque and gradient force, as given by standard electromagnetic theory. The differential equations in question will be simulated in 1D, 2D and, if time permits, 3D. By introducing an energy loss from inelastic collisions and friction with surrounding fluid, the particles will ultimately settle into stable configurations. Knowledge of these configurations is relevant for the analysis and fabrication of magnetic nanoparticle systems. A potential application is gaining control of the aggregation process through external stimuli, for instance an external magnetic field, facilitating the construction of magnetic nanoparticle configurations. The resulting configurations, could in turn be bonded to e.g. cancer cells and heated through a hysteresis loop induced by a variable external field, causing local eradication of harmful tissue.
Hold 18
Fotokatalyse af vand til hydrogen, oxygen og hydrogenperoxid
Aslak Rønnow Franzen, s163047, og Thorlákur Matthias Örnólfsson, s163990
Vejledere: Brian Seger og Shiyu Gan, Fysik
Resume:
The world needs more efficient methods of energy conversion. There is currently a lot of researchregarding the electrochemical reduction of oxygen to hydrogen peroxide, which is a very pro-mising method. In places with poor acces to sustainable electricity however, a photoelectricalreaction would be more suitable. Before the photoelectrichemical method can be used to producehydrogen peroxide commercially, there has to be a reasonable efficiency of hydrogen peroxideevolution. In this project gold nanoparticles will be used as a catalysist for the hydrogen peroxi-de reaction. Different methods of depositioning the gold nanoparticles and the thickness andposition of the nanoparticles will be tested to find the configuration with the higest efficiency ofhydrogen peroxide evolution.
Hold 19
Computational screening of materials for Battery technologies
Nanna Lysgaard Andersen, s163982, Christoffer Højgaard Egeberg, s160719, og William Sandholt Hansen, s163979
Vejleder: Juan Maria García Lastra, Energy
Resume:
This project has a focus on batteries based on lithium-ion technologies. The aim of the project is to improve various factors including the long term stability and energy density of the batteries, without sacrificing other aspects such as safety and costs. Specifically, the project will focus on the properties of Li2CrO2F as a cathode in a lithium battery. The project is part of a larger computational screening that investigates various Li2XO2F materials, with differing X transition metals such as iron, nickel, and chromium. The advantage of performing a computational screening instead of physical experiments is that it is less expensive and time consuming. The main focus is the stability of the catode during recharge of the battery. The unit structure examined is Li18Cr9O18F9. As the battery is recharged, lithium ions will be pulled out of the structure, successively reducing the number of ions in the structure. This affects the stability of the structure. The most stable structures for unit cells containing 18 to 13 Li atoms are determined by energy potential calculations. A finite number of various structures are compared to find the most stable structure through energy minimalization.
Hold 20
Plasmonic nanoparticles-assisted solar cells
Mikkel Theis Hansen, s163976, og Alexander Juul Nielsen, s164009
Vejleder: Andrei Lavrinenko, Fotonik
Resume:
With an increasing demand for green energy, efficient and stable energy solutions are needed more than ever. Solar cells are safe, stable and widely used for green energy production. Research seeks to improve efficiency without compromising longevity or stability. A main hurdle in increasing efficiency, is increasing the absorption in the semiconductor. Plasmonic nano-assisted solar cells are promising contenders in the race to achieve maximum absorption. This project aims to optimize the shape, size, material and distribution of the plasmonic particles, in order to increase absorption. Modern-day computing allows for numerical simulation of complex electrodynamic situations where an analytical solution is unattainable. The readily available simulation tools allow multiple parameter optimization without using vast amounts of time fabricating numerous devices.
Hold 21
Designing high-Q nanolaser by simulation and an analogy between quantum confinements of electrons and photons
Lasse Thorø Glente, s163972, Lise Grüner Hanson, s155830, og Søren Anton Steffensen Kuhberg, s163991
Vejleder: Il-sug Chung, Fotonik
Resume:
In this project, we model a one-dimensional photonic crystal in COMSOL. In the photonic crystal, the light is contained in a certain area. This resembles a cavity for an optoelectronic nanolaser, which can be used for power-efficient and fast CPU chips in communication. Our optical confinement can be seen as an analogy to quantum wells, which is used to obtain a better understanding of the photonic crystal. The goal of the numerical simulation is to get a maximal Q-factor by varying parameters of the crystal. The simulated crystal is a one-dimensional bar with periodic air holes. The bar contains a cluster of defects to confine the electric field. Furthermore, we find the optimal position of electrical carrier channels to avoid changing the optical properties while keeping the channels as close as possible.
Hold 22
Smart Active Materials
Emil Alstrup Jensen, s164013, Adam Mark Roth-Zawadzki, s163975, og Joakim Kryger-Baggesen, s163992
Vejledere: Nini Pryds og Vincenzo Esposito, Energy
Resume:
Must be re-written
Hold 23
Nanomechanics for graphene membranes
Frederik Grunnet Kristensen, s164003, Rasmus Kronborg Finnemann Wiuff, s163977, og Christoffer Vendelbo Sørensen, s163965
Vejledere: Mads Brandbyge og Tue Gunst, Nanotech
Resume:
Background: Since the isolation and characterisation of Graphene in 2004 by Andre Geim and Konstantin Novoselov, scientists have marvelled over the physical properties and potential application of Graphene. Being a relatively new material, many aspects and ideas are being investigated and researched at all times. Graphene yield extreme tensile strength as well as extreme electric conductivity, yet its structure is fairly simple. Graphene consists solely of carbon atoms thus making it, as carbon atoms are greatly understood in terms of chemical bonding, easy to simulate using specialised software. As graphene is a very versatile material the possibilities for research in simulation enviroments are virtually limitless. Therefore it is basically possible to make experiments limited only by imagination, in order to discover new properties and possible applications of graphene. This saves ressources before entering the lab, where where the simulated reality is tested. Purpose: A graphene layer on top of a substrate with different sized and shaped holes, would form a nanomembrane. It is expected possible to create such a nanomembrane at the size of few tens of nanometers at Nanotech with Block-copolymer lithography or TEM structuring of a substrate. In a virtual enviroment, it is possible to simulate phonons in the graphene atop of these holes in the membrane. The purpose of this project is to simulate phonons in the nanomembrane and find the optimal conditions for producing phonons in the terahertz spectrum. Method: We will employ the software Atomistic ToolKit (ATK) to calculate phonon properties of membranes as well as performing molecular dynamics of the excited membrane. The software will enable prompt setup of relevant structures so that more time is free to analysis and actual simulations.
Hold 24
Tunable water metamaterials
Ole Sørbø Borup, s163971, Christian Koefoed Schou, s163994, og Johan Bertram Thjalfe Ulvenberg, s165459
Vejleder: Andrei Lavrinenko, Fotonik
Resume:
Projektet handler om vand som metamateriale og dets egenskaber. Ved at konfigurere formen, temperaturen og retningen af periodisk opstilte vandreservoir, kan man opnå drastiske ændringer i de magnetiske og elektriske egenskaber. Konkret vil vi bruge simuleringer i programmet Comsol til at undersøge egenskaberne ved forskellige konfigurationer. En mulig anvendelse af vand som metamateriale er optimering af solceller, hvor det kan bruges til at øge absorptionen, og dermed udbyttet, hvis de rette parametre er valgt.