Roles of surfactants in perovskite solar cells.

In photovoltaics, perovskite solar cells (PSCs) have shown efficiency improvement with scalable and low-cost fabrication. This work investigates the additions of surfactants to PSCs during and after cell fabrication, and how these surfactants enhance the performance of both PSCs and hybrid PSCs. Various types of surfactants were surveyed, including amphoteric, cationic, and non-ionic, in addition to other chemicals that are showing surfactant-like behavior. Surfactants were found to improve coverage area, and reduce roughness, defects, oxygen, moisture and pinholes. They also provided better control over film thickness, grain/spherulite size, and crystal orientation. The mechanisms behind these improvements were explained, and different studies in literature were categorized based on common themes.