摘要： Hybrid organic and inorganic perovskite solar cells suffer from the lack of long-term stability and this negatively impacts the widespread application of this emerging and promising photovoltaic technology. In this work, aiming to increase the stability of perovskite films based on CH3NH3PbI3 and to deep understand the formation of 2D structures, solutions of alkylammonium chlorides containing 8, 10 and 12 carbons were introduced during the spin-coating on the surface of 3D perovskite films leading to the in situ formation of 2D structures. It was possible to identify the chemical formulae of some 2D structures formed by XRD and UV-Vis analysis of the modified films. Interestingly, the increase in the stability of the CH3NH3PbI3 films due to the formation of a 2D+3D perovskite network was only possible in planar TiO2 substrates. The increase on stability of the CH3NH3PbI3 films follows the surfactant molecule order: octylammonium (8C) > decylammonium (10C) > dodecylammonium (12C) chlorides > standard. We observed an increase of 17.6 % in the lifetime of the devices assembled with modified perovskite film compared to our standard device, which is directly linked to the improvement of the charge carrier lifetimes obtained from Time-Correlated Single Photon Counting (TCSPC) measurements.