Perovskite solar cells (PSCs) have come to the forefront of photovoltaic technology due to their impressive power conversion efficiency (PCE) of up to 25%. This high efficiency comes together with great advances regarding large-scale deposition methods and a critical enhancement of device stabilities. However, important challenges remain in the shadows for commercialization of this technology. This thesis addresses issues related with the stability under real operation condicions and those associated with the interfacial interactions. For both purposes, two main perovskite materials based in methylammonium lead halides (MAPbX3) were optimized: MAPbI3 and MAPbBr3. Coupled with a wide number of instrumentak techniques for bulk and interfacial characterization, a robust method to fabricate PSCs under moisture conditions was developed using iodide derivatives. On the other han, interfacial engineering with lithium additives in MAPbBr3 devices promoted a decrease in recombination mechanisms allowing to achieve a record open circuit poetential approaching 1.6 V.
