Toward clean production of plastic perovskite solar cell: Composition-tailored perovskite absorber made from aqueous lead nitrate precursor

Highlights: • A low-toxicity production of plastic perovskite solar cells is demonstrated. • The kinetics of intermediate ion exchange among NO₃⁻ and mixed cation/anion is deeply investigated. • The hybrid-composition perovskite made from aqueous lead nitrate precursor shows high crystallinity and less defects. • A record-high PCE of brookite-TiO₂ scaffold-type plastic perovskite solar cells of 16.50% is achieved. -- Abstract: Even though the power conversion efficiency (PCE) of plastic perovskite solar cells (P-PSCs) is increased to 18.40%, the majority of solvent systems implemented for deposition of perovskites are hazardous to handle, which will greatly hinder the future development of plastic photovoltaic devices. In this study, composition-tailored hybrid perovskite from a low-toxicity aqueous lead nitrate precursor was fabricated by regulating the conversion kinetics. We systematically investigated the interplay among NO₃⁻ and mixed cation/anion in the intermediate ion exchange and renovated the interpretation of hybrid-composition perovskite conversion. The fully ambient-processed hybrid-composition perovskite with high crystallinity and less defects was applied in a brookite TiO₂ scaffold-based P-PSCs, which achieved a record-high PCE of scaffold-type P-PSC of 16.50%. The interaction of environmentally-friendly aqueous lead nitrate precursor with hybrid ions advanced the understanding of perovskite conversion mechanism and had a great potential to realize the low-toxic fabrication process by using water as a processing solvent in the ambient atmosphere.