Investigations on knife and slot die coating and processing of polymer nanoparticle films for hybrid polymer solar cells

Hybrid solar cells have a high potential to become an inexpensive alternative to conventional photovoltaic. Their major advantage is the possibility to produce them by solvent based deposition in a cost efficient roll to roll (R2R) process. Due to their high optical absorption, high conductivity, tunable particle size and shape they could proof superior to fullerenes.Currently all hybrid cells are produced by spin-coating on laboratory scale. Coating technologies for pilot scale production are discussed. We present an experimental setup that was designed to investigate the coating and drying of hybrid layers with roll to roll compatible methods. Specific problems of processing semiconducting nanoparticle/polymer films such as minimization of hold-up are addressed. First results indicate that the processing conditions determine not only the morphology of the film but also its optoelectric properties such as light absorption, conductivity and eventually cell efficiency. Finally, we can report the preparation of knife and slot die coated hybrid solar cells with up to 1.18% PCE for knife coated devices.