Flexible semi‐transparent organic photovoltaic (OPV) modules were manufactured by roll‐to‐roll slot–die coating of three functional layers [ZnO, photoactive layer, and poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)] and either the screen printing or inkjet printing of the top electrodes. A poly(3‐hexylthiophene):[6,6] phenyl C61‐butyric acid methyl ester (P3HT:PCBM) layer deposited from non‐chlorinated solvents was used as the absorber layer. The modules were realized by slot–die coating of the layers onto a laser‐patterned polyethylene terephthalate/indium‐tin oxide (PET/ITO) substrate, followed by laser structuring of all coated layers. The top electrodes were realized by high‐resolution printing, which, combined with laser patterning of other layers, enables manufacturing of the modules with high geometrical fill factor (92.5 %). The modules have an active area of 156 cm2, and contain 13 serially interconnected cells. Two semitransparent electrodes (ITO from the bottom and PEDOT:PSS/Ag‐grid from the top side) allow the absorption of photons incident from both sides. The performance of the modules was evaluated and compared among the modules by considering the following factors: (i) roll‐to‐roll slot–die coated vs. spin‐coated layers, (ii) inkjet‐printed vs. screen‐printed top electrodes, (iii) top vs. bottom illumination. The demonstrated technology is one of the proven feasible ways towards industrial manufacturing of the OPV modules.

Abstract:We have experimentally studied the polarization-dependent transmission properties of a nanoslit in a gold film as a function of its width. The slit exhibits strong birefringence and dichroism. We find, surprisingly, that the transmission of the polarization parallel to the slit only disappears when the slit is much narrower than half a wavelength, while the transmission of the perpendicular component is reduced by the excitation of surface plasmons. We exploit the slit's dichroism and birefringence to realize a quarter-wave retarder.

A retarding field energy analyzer (RFEA) with grids created by laser-cutting a honeycomb mesh in a 50 μm thick molybdenum foil is presented. The flat grids span an area of 1 cm and have high transmission (20 μm wide walls between 150 μm wide meshes). The molybdenum grids were tested in a 3-grid RFEA configuration with an analyzer depth of 0.87 mm.

Nonencapsulated CIGSSe solar cells, with a silver grid, were exposed to different temperatures for various periods in order to measure the effect of the heat exposure in CIGSSe modules. The heat treatment time and temperature were varied during the experiments, which were executed at atmospheric conditions. In all the cases, after reaching a temperature of about 300°C, theIVmeasurement showed a reduction of 2-3% in terms ofVOCandJSC. This is confirmed, respectively, by Raman and EQE measurements as well. The efficiency drop was −7%, −29%, and −48%, respectively, for 30 seconds, 300 seconds, and 600 seconds of exposure time. With temperatures larger than 225°C, the series resistance starts to increase exponentially and a secondary barrier becomes visible in theIVcurve. This barrier prevents the extraction of electrons and consequently reducing the solar cells efficiency. Lock-in thermography demonstrated the formation of shunts on the mechanical scribes only for 300 and 600 seconds exposure times. The shunt resistance reduction is in the range of 5% for all time periods.

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