Reduced dimensionality hybrid perovskites are structures formed by the intercalation of inorganic and organic layers, where the inclusion of a large organic cation producing the separation of a determined number of inorganic layers (n), which can range from one (2D) to an infinity arrangement (3D). The number of inorganic perovskite layers confined between organic layers can be tailored by adjusting ratio between the small organic cation, i.e. CH3NH3⁺ which is adequate for perovskite formation, and a larger cation, making that the inorganic part becomes a 2D/3D structure. Actually, 2D/3D perovskite-based solar cells have been emerged as an alternative to pure 3D perovskites with the aim to improve their long term stability. Several studies have been reported on 2D/3D perovskites prepared using only aliphatic ammonium salts as phenylethylammonium iodide, butylammonium iodide. Recently, has been shown one year stable 2D/3D perovskite based devices fabricated using 5-ammonium valeric acid iodide.

The use of aromatic cations is scarce in crystallographic studies and null in photovoltaic applications. In this way, we use anilinium iodide (C₆H₅NH₃I=AnyI) as spacer cation in the preparation of a 2D and 2D/3D perovskite based solar cells (AnyI)₂(CH₃I)_n-1(PbI₂)n (n=1 to 5), with the aim of to take advantage of the electronic delocalization properties, applied to the charge transport. At the same time it has been carried out a comparative study using the well-known 2D/3D butylammoniumiodide (BAI) perovskite, that has been considered as reference. Photovoltaic performance measurements shows that power conversion efficiency increase systematically on going from n=1 to n=5 (0.66 to 5.96 %, respectively) and the performance of the device with anilinium exhibits a significantly higher performance than its respective reference prepared with butylammonium (0.01 to 3.02 for n=1 to n=5). Absorbance measurements of the films fabricated with BAI show a progression of the excitonic bands on going from n=1 to n=5. In the other hand, when we use the conjugated cation the progression of the exciton absorption peaks is not clearly observed and the absorption band edge is redshifted, near to 1.6 eV, since the film where n=2, suggesting that the excitons are practically ionized into free carriers, even for films with n=2.

Our results show that the application of electronic conjugated molecules in the synthesis of 2D/3D materials can generate a new kind of materials with improved photovoltaic and optoelectronic properties.