Preparation of a TiO2 Porous Layer by Molding of Polymer Beads for Perovskite Solar Cells Application

The perovskite based solar cells is a new generation solar cell type, the perovskite crystals act as photo-charge-generating materials with organic and inorganic elements more commonly referred to as "halide hybrid perovskite" (ABX3 with A the organic part, B the inorganic part and X an halogen). In addition, they are low-cost materials that are easy to develop, which is a major advantage for this type of cell. There are different types of perovskite-based solar cells (PSC) with different designs. This work focuses on the so-called "monolithic" PSC configuration, which is composed of different porous layers; including TiO2 deposited from commercial pastes by "screen-printing" technique into perovskite crystals infiltrate. In this cell graphite (p type) is used as cathode while FTO (Fluorine Tin Oxide, n type) on glass is used as anode. The aim is to obtain a TiO2 layer with a higher porous volume with respect to the one done commercially, so the quantity of photo-active materials that infiltrates it can be increased and in this sense higher efficiency could be reached. Indeed, up to 13 % has been obtained for the optimized cells with the new configuration of porous TiO2 layer obtained by bead molding in comparison with a 8 % for reference cells (commercially produced porous layer). Keywords: perovskites solar cells, TiO2 porous layer, polymer beads, sol-gel method.