Scientific blog
PhD report (June 2015) A.Mzyk 
Monday, 6 July, 2015, 13:19
Posted by Aldona Mzyk
In June, I have worked on cell growth on micropatterned surfaces with different geometries obtained by laser interference lithography. Results of the PhD thesis research concept continuation will be presented at the ESB 2015 conference which will be held in Krakow this summer .
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Ph.D finish - MTrybula 
Tuesday, 30 June, 2015, 12:45
Posted by Marcela Trybula
The main subject of the research were three liquid ternary Al-Li-Zn alloys of compositions corresponding to three intermetallic phases present in the solid state of the Al-Li-Zn system. Foundation for analysis of the ternary system was laid bythe investigation of three constituent binaries: Al-Li, Li-Zn and al-Zn.
This thesis focuses on describing the relationship between structure and thermodynamic, and transport properties of the selected liquid Al-Li-Zn alloys. This relationship was analyzed using a wide variety of experimental and computational methods. Experimental measurements of thermodynamic functions were performed using the galvanic cell method. Physicochemical properties were investigated using the draining crucible method (DC). Within the computational methods applied, classical and ab initio molecular dynamics simulations can be mentioned. Chemical short-range order characteristics was obtained by computing the short-range order parameter from ab initio molecular dynamics results. The topology of local atom arrangement was investigated using the Common Neighbor Analysis (CNA) and Voronoi Analysis (VA). Physicochemical properties analysis was supplemented by the data obtained using semi-empirical models.
The studies performed gave a coherent and detailed description of Al-Li-Zn alloys liquid phase, including physicochemical, thermodynamic and structural properties. The applied methodology allowed to confimr the hypothesis stated.
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PhinisheD 
Wednesday, 17 June, 2015, 15:10
Posted by Krzysztof Glowinski
On the important day, the eleventh of May, I finally defended my dissertation.
The defense was quick and smooth :)
Since this is the end of this story, let me just summarize my work in a nutshell:

The most basic aspect of analysis of grain boundaries is their geometry. With recent development of experimental techniques for three-dimensional (3D) microstructure imaging, it became relatively easy to collect large sets of boundary parameters. This dissertation is devoted to development of effective tools for analysis of such 3D data sets with all five so-called macroscopic boundary parameters taken into consideration. New reliable and fast-to-calculate parameters for recognizing whether a given boundary can be classified as tilt, twist, symmetric, or 180-tilt are defined. (It is shown that existing solutions are inapplicable to error-affected experimental data or do not take into account crystal symmetry.) Using the new parameters, the frequencies of occurrence of characteristic boundaries are estimated for real materials. A basic characteristic of a boundary network is a distribution of boundaries with respect to their macroscopic parameters. To avoid artifacts caused by the currently used computation method, it is proposed to utilize kernel density estimation (KDE) and to determine boundary distributions based on distance functions defined in the five-dimensional space of boundary parameters. Based on diverse example distributions obtained for several metals, it is shown that with new computational approach, the resulting distributions are clearly more accurate. A scheme of interpretation of the distributions is also proposed. It includes evaluation of their statistical reliability, identification of their symmetries, and verification whether extrema in such distributions correspond to boundaries of characteristic geometry. KDE is also adapted to computation of boundary-plane distributions independent of misorientations. In parallel to developing the abovementioned methods, a package of computer programs including implementations of the new approaches has been created.
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Now, the end of PhD distress 
Friday, 12 June, 2015, 01:19
Posted by Piotr Drzymala
Finally, I got PhD degree. The book entitled "Microstructural conditions of plastic deformation of Mg-based AZ31 alloy" is printed and available. In the next months I'm going to focus on cooperation with some supervisors of the projects.
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ZStarowicz Summary 
Thursday, 11 June, 2015, 16:57
Posted by Zbigniew Starowicz
Finally the studies are finished. The scientific degree of Doctor of Phylosophy has been defended. The thesis entilted "Eleboration and characterisation of plasmonic structures for photovoltaic applications" was published. Here is summary of my disertation:
Modern solar cells in their architecture more often combine the reduced amount of photoactive materials with increased energy conversion efficiency, in order to minimized the cost of solar energy. With the reduction of cell thickness in the thin-film technologies and new concepts of cells, based on nanomaterials, it is no longer possible to use heretofore known methods, such as surface texturisation or antireflection coatings, for reducing the optical losses. It is necessary to elaborate new materials and structures for coupling of light with objects in nonoscale. Such capabilities provide plasmonic metal structures.
The aim of this work was to develop and execute plasmonic structures based on silver nanoparticles that could be applied in solar cells. Basic phenomena that cause the validity of the use of such structures are strong light scattering and strengthening the near electric field around the nanoparticle at the surface plasmon resonance conditions. Silver was selected due to the occurrence of plasmon resonance in the significant from the point of view of photovoltaic wavelengths range, low parasitic absorption and good flexibility of fabrication of various types of nanostructures.
Within the presented dissertation a special emphasis was put on the methods of producing silver nanostructures potentially useful in photovoltaics and their microstructural aspects, as well as the resulting properties. Plasmonic properties strongly dependent on parameters such as the size and shape of the nanoparticles and the local environment, therefore, good control of these microstructure parameters is highly required. Three methods of preparation have been selected, which were additionally assisted by computer simulations. These were the photochemical deposition, nanoisland formation from the thin layers (Metal Island Film, MIF) and the deposition from colloids by electrostatic self-assembly process.
During the work the various research methods were used to characterize the microstructure of nanoparticles collections and structure of tested materials (SEM, AFM, TEM, XRD, XPS, Raman and infrared spectroscopy) as well as to determine optoelectronic properties (ellipsometry, UV-VIS-NIR spectroscopy, I-V characteristics, EQE). Significant progress in understanding the research field and connected issues were enabled by computer simulations for specifying the interaction of nanoparticles with light.
In terms of the photochemical methods result of this work was determination of conditions for embedding small silver nanoparticles on the surface of titanium dioxide. The average size of the nanoparticles is below 50 nm, which is changed with the change of concentration of the precursor of silver and the intensity of the laser light. The main feature of these nanoparticles was strongly strengthening short electric field. The possibility of using this kind of organic particles in the cells. Within the MIF method the deposition parameters of the Ag layers were studied as factors influencing the microstructure of resulted nanoislands. However, the main emphasis was on concept of application of nanoparticles on the front surface of the cell. For this configuration, the optimal size of the nanoparticles and surface coverage were investigated using computer simulations. Then the process of adsorption of nanoparticles from colloidal suspensions were investigated. The measured properties of obtained samples were used to re-define computer simulations taking into account actual features analyzed systems. The final result was the application of nanoparticles in silicon solar cells, yielding the highest heretofore improvement of the cell current response for structures obtained by this method.

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