Investigating the Fabrication of Perovskite Solar Cells by Ultrasonic Spray Coating: A Design of Experiments Approach

The incrementally rising efficiency of perovskite-based photovoltaic devices has established technology as a hot topic in past years. Transitioning this class of materials from laboratorial to commercial application is key to the future of clean energy generation. In the interest of this transition, scalable fabrication and reproducibility are challenges to be overcome. Additionally, being a highly dynamic field with fast-paced innovation, perovskite research lacks in structured comprehensive studies focusing on the processing parameters, especially when compared to commercial technologies, such as silicon-based devices. This study proposes a design of experiments (DoE) approach to analyze and optimize the fabrication of perovskite thin films by ultrasonic spray coating, a scalable technique. The investigation of deposition parameters one factor at a time (OFAT) and the more in-depth full factorial analysis of three key input variables allowed the assessment of the impact level of each factor on the quality and performance of the obtained films of the fabricated photovoltaic devices. Furthermore, the full factorial analysis reveals the presence of interactions between factors. The study revealed that a shorter distance between the air gun and the sample (2 cm) coupled with high gas pressure (7.6 bar) during the quenching step were the most influential parameters for the production of high-quality films, leading to an average efficiency of 14.8%.