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One of the components in a particle accelerator is the photo-injector. In this, the electron beam is generated, accelerated and focused. To achieve the focusing process a solenoid composed of superconducting material connected to a power supply in a certain way is necessary. In the assembly of the photo-injector for the bERLinPro project occurred an error in the connection of the solenoid. Creating an unknown circuit inside of a close system, with high vacuum. This circuit does not allow a process of stabilization of the voltage in not less than 45 min, when desired is less than one minute. In this project is intended toRead More →

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Organic-inorganic hybrid metal-halide perovskites are very interesting materials and can be used as an absorber in photovoltaic device. Efficiencies of solar cells based on metal halide perovskites above 20% have been reported, however, the long-term stability of related solar cells is still challenging. The robustness of triple cation perovskite films seems to indicate the way to obtain a long-term stability. The samples used on the experiments consisted on a substrate with a layer of porphyrin. Their characterization by surface photovoltage (SPV) technique was performed by analyzing its transport length in interaction with the perovskite. The procedure included the measurements before and after the perovskite layerRead More →

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Due to their unique physical properties and reactivity, metallic nanoparticles (MNPs) play an important role in the design of novel nanodevices, especially in the field of molecular electronics. The optical properties of small MNPs are often determined by the so-called plasmon resonance, which involves the coherent motion of conduction band electrons driven by an external electromagnetic field. In this project, we specifically investigate absorption spectra and electron dynamics upon photoexcitation, for example the difference electron density isosurfaces during excitation by a laser-pulse at the plasmon frequency. Therefore we study the plasmonic response of small, atomistically modeled MNPs using real-time time-dependent density functional theory (RT-TDDFT), asRead More →

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Transparent conductive oxides are an important material in the photovoltaic and semiconductor industry. In the past years, Hydrogen doped Indium Oxide (IOH) has shown outstanding electrical and optical properties compared to Aluminum doped Zinc Oxide (AZO). Therefore, it has a high potential as a transparent front contact in CIGS solar cells and modules where this material is commonly used. In this project, we are investigating the properties of pulsed DC-sputtered IOH before and after an annealing on varying substrate layers to successfully implement the material in CIGS. This will help to improve the efficiency of the devices due to a better management of the sunlight.     TheRead More →

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  “We live in the silicon era.” Silicon is still by far the most widely used PV material. The latest 2017 world record solar cell for Silicon heterostructures (HIT) achieved an ECE of 26.63%. At its hearth, the materials used are amorphous-Silicon hydrogen passivated and crystalline silicon (aSi:H-cSi). Such an interface showcases interesting electrical and electro-chemical properties. Evidence of its potential capabilities for reducing defect densities and their photon absorption with its two energy band gaps have been observed. Both phenomena, if correctly engineered, are known to help increase efficiency[1]. Our curiosity driven investigation by surface photovoltage (SPV) spectroscopy and by SPV transient measurements mayRead More →

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SnWO4 thin film photoelectrodes for solar water splitting Solar water splitting offers a solution for solar energy storage problem, since the generated hydrogen can be stored as a renewable fuel. However, a suitable photoelectrode material for water oxidation reaction is still elusive. The reason for this is that the semiconducting materials have to meet the stringent requirements. For example, the elements of the electrode have to be earth-abundant and allow stability in aqueous solution. Furthermore, the photoelectrode has to absorb most of the visible spectrum of the sun to ensure a high solar-to-hydrogen efficiency. In this work, a new promising n-type semiconductor α-SnWO4 was examined.Read More →

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Why it’s important? Development of photovoltaic and other energy materials requires a lot of experiments and comprehensive processing of data is vital for successful research in this fields.  Unfortunately, sometimes measurement systems software couldn’t provide all necessary features, e.g. combining data from different samples, excluding inaccurate data, etc. That’s why we are currently developing complex data analysis program for state-of-the-art Hall Measurement system. Program itself is complex project in Python high-level programming language with a lot of different plotting and calculation options, such as calculating charge carrier concentration, mobility and many other parameters. It’s also possible to analyze AC field measurements, which is useful forRead More →

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Superconductive materials, usually niobium, are used in cavities of particle Accelerators.  In order to measure some key parameters of niobium, such as surface resistance, critical magnetic field and penetration depth, at radio frequency( as particle accelerators are working in that range) a test setup is used, which is called as quadrupole resonator.  A superconducting sample is mounted to the test setup, quadrupole resonator creates the desired frequency and here with the magnetic field. In order to calculate those key parameters, temperature and dissipated power are measured. Later, those measurements are used to calculate and determine the key parameters with the help of MatLab. My projectRead More →

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Superconducting radio-frequency photoelectron injectors (SRF photoinjectors) are promising electron sources for high brightness accelerators with high average current and short pulse duration. The task of the GunLab facility is to ensure safe operation of the SRF gun, check the theoretical model for the beam dynamics by measurements and to find an optimum working point for BERLinPro. Data acquisition and analysis for GunLab is important to have a better understanding of the gun performance and the efficiency of the diagnostic tools. During this two –month research work, different experimental measurements were made for the dipole and quadrupole magnets and then coding, analyzing data with Matlab softwareRead More →

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Nafion® is the most used polymer in Proton Exchange Membrane Fuel Cells (PEMFC) that work in the temperature range of 80-130 ºC. The PEMFC efficiency is controlled by a Nafion’s thermal transition, labeled α (Tα ~ 110 ºC). Above the α-transition, irreversible modifications of the Nafion chemical interactions is responsible for a dramatic degradation of Nafion proton conductivity that can lead to the fuel cell collapse. Such transition has been rarely studied by infrared spectroscopy (IR). The IR would allow understanding the specific interactions among Nafion’s functional groups underlying α-transition. Thus, this investigation would help boosting PEMFC technology as well as advancing the development high-performance polymerRead More →