M. Staszuk

Application Examples for the Different Measurement Modes of Electrical Properties of the Solar Cells

The aim of the paper was to apply the newly developed instruments ‘Corescan’ and ‘Sherescan’ in order to measure the essential parameters of producing solar cells in comparison with the standard techniques. The standard technique named the Transmission Line Method (TLM) is one way to monitor contacting process to measure contact resistance locally between the substrate and metallization. Nowadays, contact resistance is measured over the whole photovoltaic cell using Corescanner instrument. The Sherescan device in comparison with standard devices gives a possibility to measure the sheet resistance of the emitter of silicon wafers and determine of both P/N recognition and metal resistance. The Screen Printing (SP) method is the most widely used contact formation technique for commercial silicon solar cells. The contact resistance of manufactured front metallization depends of both the paste composition and co-firing conditions. Screen printed front side metallization and next to co-fired in the infrared conveyor furnace was carried out at various temperature from 770◦C to 920◦C. The silver paste used in the present paper is commercial. The investigations were carried out on monocrystalline silicon wafers. The topography of co-fired in the infrared belt furnace front metallization was investigated using the atomic force microscope and scanning electron microscope (SEM). There were researched also cross sections of front contacts using SEM microscope. Front contacts of the solar cells were formed on non-textured silicon surface with coated antireflection layer. On one hand, based on electrical properties investigations using Sherescan instrument it was obtained the knowledge of the emitter sheet resistance across the surface of a wafer, what is essential in optimizing the emitter diffusion process. On the other hand, it was found using Corescan instrument that the higher temperature apparently results in a strongly decreased contact resistance.

Preliminary Studies on the Properties of Novel Polymeric Composite Materials Based on Polysuccinates

This study aimed to prepare novel biodegradable polymeric composites based on poly(3-allyloxy-1,2-propylene) succinate (PSAGE). These composite materials are composed of poly(ester-anhydride) (PEA) microspheres embedded in polyester matrix prepared by crosslinking PSAGE with oligo(1,2-propylene maleate) and methacrylic monomers. Methyl methacrylate and one of hydrophilic oligo(ethylene glycol) dimethacrytes with different length of oligooxyethylene chains were used as polymerizable solvents. Incorporation of microspheres that degrade faster than crosslinked polyester matrices enables formation of porous structure. The obtained materials are liquid before curing and harden in several minutes with moderate exothermic effect. The effect of the composition of polyester matrices and kind of PEA microspheres used on selected properties, such as water sorption, mechanical strength, porosity, and hydrolytic degradation behavior, was investigated. The morphology of the cured composite materials subjected to hydrolytic degradation was evaluated by SEM.

Refinement effect of RE in light weight Mg–Li–Al alloys

The effect of 2xa0mass% rare earth elements (RE) as in mischmetal state on the structure, thermal behaviour and mechanical properties of Mg–xLi–4Al (xu2009=u20094, 8 and 12 by mass percentage). The thermo-derivative analysis was implemented using the UMSA platform (Universal Metallurgical Simulator and Analyzer) with cooling rate approx. ≈xa00.6xa0°Cxa0s−1 that correspond to natural cooling. Microstructural evaluations were identified by X-ray diffraction, scanning electron microscopy, light microscope and energy-dispersive X-ray spectroscopy. Obtained results from the thermal derivative analysis allowed determining the solidification pathways for Mg–Li–Al–RE alloy. The addition of grain refinement causes changes in crystallisation process. The addition of RE elements affected an enhancement in mechanical properties, which was associated with the development of intermetallic compounds; the maximum increases in hardness at level 240% was observed for single α-phase alloy and at level 19% for αu2009+u2009β alloy.

Rare earth-doped lead titanate zirconate grown on carbon fibers by microwave-assisted hydrothermal synthesis

This study aimed to develop a flexible carbon fiber/oxide layer coating composite with improved electrical properties for use in electronic devices. For this, lead titanate zirconate, cerium-doped lead titanate zirconate, and yttrium-doped lead titanate zirconate were grown on carbon fibers via microwaves-assisted hydrothermal synthesis. The performed synthesis presented advantages when compared to conventional routes used in nanoparticles obtention since it allows the morphological control even at low temperatures. Carbon fiber was selected as substrates due to their thermal stability, excellent mechanical properties, chemical characteristics that allow the creation of functional groups on their surface, and good microwave radiation absorption. The composites were investigated by X-ray diffraction, spectroscopy Raman, and field emission scanning electron microscopy. The electrochemical evaluations were made by four-point probe method, cyclic voltammetry, and electrochemical impedance spectroscopy. The syntheses were successful and the carbon fiber coated with lead zirconate titanate had promissory results, with a boost in the electrical conductivity and better capacitance behavior when compared to the undoped carbon fiber, showing to be a good alternative for applications in electrical devices.

Structure and Properties of the Multicomponent and Nanostructural Coatings on the Sintered Tool Materials

This chapter presents a general characteristic of sintered tool materials, in particular sintered sialons, nitride ceramics, injection-moulded ceramic-metallic tool materials and cemented carbides and a general characteristic of their surface treatment technology and especially chemical vapour deposition (CVD) and physical vapour deposition (PVD) techniques. The results of our investigations in technology foresight methods concerning the development prospects of surface engineering of sintered tool materials are presented. In the next subsection, we discuss the outcomes of multifaceted research carried out with advanced materials engineering methods, including high-resolution transmission electron microscopy, into the structure and properties of multicomponent, graded and multilayer coatings on the investigated tool materials, including the newly developed injection moulded ceramic-metallic tool materials. Special attention was drawn to a one-dimensional structure of the studied PVD and CVD coatings and its impact on the properties of coatings.

Study of the Electrochemical Properties of 316LVM Steel with TiO 2 Layer Deposited by Means of the ALD Method

ALD is a variation of CVD, which, for example, found application in depositing two-component compounds, such as SiO2 or TiO2. In the case of layers applied to the surfaces of products intended for contact with blood, important determinants include, aside from chemical composition, achieving an appropriate thickness and adequate sealing. A secure layer of the right thickness forms an effective barrier that protects the metal nanomaterial from the effects of corrosive environments (Shan et al. in Surf Coat Technol 202:2399–2402, 2008 [1]). Thin oxide layers based on such elements such as Ti or Si (up to 250 nm) are more hemocompatible, which significantly reduces the risk of complications related to the disseminated intravascular coagulation (DIC) process, for example. Aside from improved hemocompatibility, another important issue related to creating surface layers is the ability to achieve an appropriate set of electrochemical parameters. For this reason, tests were performed concerning the electrochemical properties of the TiO2 layers deposited on the surfaces of AISI 316LVM steel samples using ALD under varied process parameters. First, potentiodynamic and potentiostatic measurements were taken, which enabled pitting and crevice corrosion resistance to be assessed. Secondly, impedance measurements were performed to enable interpretation of the processes and phenomena occurring at the TiO2 layer—electrolyte (synthetic plasma) interface. Complementary examination of surface topography was performed using a scanning electron microscope (SEM).

Application of the Finite Element Method for Modelling of the Spatial Distribution of Residual Stresses in Hybrid Surface Layers

The presented investigations concern PVD/CVD surface treatment performed on samples of heat treated cast magnesium and aluminium alloys and properties modelling of obtained coatings using the finite element method (FEM). In order to identify the structure and fractures of the analysed surface coatings, investigations using the scanning electron microscope Zeiss Supra 35 were performed. Evaluation of the adhesion of the PVD/CVD coatings was carried out using a scratch test. The obtained coatings—Ti/Ti(C,N)-gradient/CrN; Ti/Ti(C,N)-gradient/(Ti,Al)N; Ti/(Ti,Si)N-gradient/(Ti,Si)N as well coatings: Cr/CrN-gradient/CrN; Cr/CrN-gradient/TiN and Ti/DLC-gradient/DLC are characterized by a clear heterogeneity of the surface associated with the presence of microparticles in the structure in form of droplets broken out of the target during the deposition process, as well immersions occurring in the surface due to the loss of some droplets during solidification. It was also found that the applied coatings are characterized with a mono-, di-, or multi-layer structure according to the applied layer system; the individual layers are applied uniformly and tightly adhere to the substrate and to each other. The obtained results of the numerical FEM analysis, have enabled a full integration of the material engineering knowledge and informatics tools, confirming compliance of the simulation model with the obtained experimental results.