Abstract
We have developed an electrospraying technique inspired from Marangoni flow seen in nature. We demonstrate our ability to synthesise highly crystalline uniform perovskite thin films with enhanced coverage and high absorption. Due to a difference in the vapour pressure of DMSO and NMP, a gradient force is developed that helps in propagating the incoming precursor droplet to coalesce and merge with other droplets thus inducing a dynamic self-assembly within the thin film. This results in thin films with high uniformity and good morphological and topological characteristics, that collectivelty resulted in a respectable PCE of greater than 14%. Optical studies are conducted in parallel to better understand the energy phase space of perovskite crystals. The high temperature tetragonal phase showed a high recombination rate of 180 ns, ideal for photovoltaic performances, while the low temperature measurements reveal considerable complexity in spectral and dynamic properties that demand further invesgtiation.