Selective laser patterning for integrative serious connection has been industrially established in inorganic thin film solar cells based on glass substrates since a few years. In organic solar cells (OSC) the used materials significantly differ in terms of their patterning behavior. Due to their processability by wet chemical methods inverted architectures are often preferred in organic solar cells which allow the patterning by ultrashort laser pulses in substrate and superstrate configuration. Starting with an introduction of the ablation mechanisms taking place in OSC thin films, an overview of the current state-of-the-art in laser patterning of organic solar cells is presented. Besides progress in research also current achievements in industrial applications are illustrated.
Flexible organic photovoltaics have gained increasing interests during the last decades. Toward increasing the
efficiency and decreasing the cost per Watt, they are on their way to the market. The approach of laser patterning
technology has been expected to motivate the industrialization of organic photovoltaics. In this paper high repetition
picosecond laser radiation fabricated trenches of ITO on flexible PET (Polyethylene terephthalate) substrate are
presented. In order to obtain clean removal ITO layer without damaging PET substrate, 1064nm, 532nm and 355nm
wavelengths with different laser fluencies and scanning strategies are applied and optimized. The results reveal the
different principles for ablation of ITO layer with different wavelengths. The ITO layer is successfully and selectively
removed by 1064nm laser radiation with 0.63J/cm<sup>2</sup> fluence and 4m/s scanning speed.