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The Coach6 software and the CoachLabII+ measuring console coupled with a computer and equipped with appropriate voltage and current sensors were used to determine the current-voltage and power-voltage characteristics of the photovoltaic cells. The current-voltage and power-voltage characteristics for a single cell and cells connected in series and in parallel were tested depending on the light intensity. Using a simplified theoretical model of a photovoltaic cell based on the one-diode equivalent circuit and Shockley diode equation, the ideality factor, diode saturation current and source current were determined, fitting the appropriate theoretical relationship to the measurement results. Based on the current-voltage and power-voltage characteristics, the short-circuit current, open circuit voltage, maximum power, fill factor, conversion efficiency and load resistance were determined. The dependence of the determined parameters on the light intensity was discussed.

The article presents the basic properties of liquid crystals with particular emphasis on their use in the construction of liquid crystal displays. The basic properties of liquid crystal displays, their structure and principle of operation are discussed. The selected examples show the benefits of using liquid crystal displays in vehicle transportation and aviation.

Real-time dielectric relaxation spectroscopy for a molecular beam deposited glass forming liquids is proposed as a versatile approach for the study of the dynamic glass transition in geometric confinement. To achieve the highest sensitivity down to monomolecular organic layers in a wide frequency range (0.1 - 10^7 Hz) during simultaneous deposition and desorption, we have used μm spaced interdigitated electrodes under ultrahigh vacuum conditions. Experiments using glycerol deposited on fused silica at -40◦C revealed a dielectric glass transition process for a layer thickness as low as 0.7 nm. While its peak position hardly changes upon thickness reduction, a clear broadening of the relaxation peak is observed that implies an increasing heterogeneous mobility scenario for the thinnest films caused by molecules being part of a reduced (at the substrate) or enhanced (free surface) mobility layer. This finding is supported by desorption experiments that reveal a strong retardation of the desorption rate for films below 1 nm. ispartof: European Physical Journal. Special Topics vol:189 issue:1 pages:181-186 ispartof: location:Grenoble status: published