Transformations in Perovskite Photovoltaics: Film Formation, Processing Conditions, and Recovery Outlook

Abstract: Organometallic halide perovskites have garnered considerable attention in recent times due to their promising optoelectronic attributes, particularly within the realm of solar photovoltaics (PV). How perovskite films form is of utmost significance in shaping their structural and functional characteristics. In this context, the application of methylamine vapour during the precursor deposition and subsequent treatment during the film formation stages emerges as crucial for the development of high-quality perovskite films for solar cell applications. The utilization of methylamine vapour annealing is pivotal in improving the crystallinity, morphology, and overall integrity of perovskite films. This work investigates the characteristics of perovskite films based on methylamine lead iodide, focusing on aspects such as crystallographic structure and vibrational modes, which are directly linked to the performance of the devices. The maximum power conversion efficiencies (PCE) obtained are 19.5% and 18.6% using 1-step and 2-step processes are obtained. The effect of factors like trap states, film homogeneity, and interfaces on the device performance are explored through capacitance measurements, photoluminescence, and electroluminescence behaviour. The recombination behaviour of the perovskite films is correlated with the crystallographic properties. These findings provide valuable insights into the influence of different processing techniques, such as methylamine vapour treatment and vacuum annealing, on rejuvenating perovskite solar cells.