The dye sensitized solar cell (DSSC) is a third generation photovoltaic technology with conversion efficiencies as high as 14 %, which has been achieved through the optimization of the cell components and a better understanding of the mechanisms of charge generation and recombination processes involved in the solar cell functioning. The selection of the most promising components (e.g., the film material, the dye and the redox couple) related with their single properties is the starting point in the efficiency improvement process. Based on this observation, ZnO is one of the most promising alternatives to replace TiO₂ as electron transporting material in the DSSCs, this due to its higher electron mobility (comparing with TiO₂), where the ZnO-organic dyes combination promises an increase in the overall efficiency of the solar device.

Poor chemical stability of ZnO (compared to TiO₂) during the sensitization process has been reported as an important efficiency-limiting factor in ZnO-based DSSCs, related to the "acidic" character of the groups through which the molecule binds to the surface of the material. Piperidine-substituted perylene-monoanhydride derivatives not only show light absorption in a wide range of the electromagnetic spectra and high molar extinction coefficients, making them attractive molecular absorbers for this application, but also show to be a factible route to overcome the stability issue associated to the ZnO, anchoring the molecule at the semiconductor surface through the rupture of the anhydride moiety. In this work we study the suitability of sensitizers based on piperidine-substituted perylene-monoanhydride derivatives to interact with ZnO (evaluating their ability to show "aggregation"), and their performance in photovoltaic devices related to the optical and energetic features of these molecules, determined by spectroscopic and electrochemical techniques.