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 →

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 →

  “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 →

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 →

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 →

    Figure 1 :  The mini solar module after scribing.   The laser scribing, which means digging lines within the layers of the solar cells, is a significant process within the fabrication scheme for solar cells modules. Scribing is done in order to contact the cells within the module, upscale the area of ​​these manufactured modules for industrial applications and save the efficiency in the meantime. My project is concerned with the scribing of the absorber material layer of CIGS thin film solar cells. This involves optimization of the parameters of the lasers beams, pico and nanosecond ones , and comparing, qualitatively and quantitatively,Read More →