Manipulating Formation Kinetics in Low‐Toxicity Solvent Methanol‐Based Inks for Perovskite Solar Cells via Multifunctional Pore‐guiding Agents
Jiarong Wu, Yujie Liu, Runkang Wang, Jiafan Zhang, Lei Gu, Haoyi Zhang, Lixia Ren, Shengzhong (Frank) Liu, Peng ZhaiABSTRACT
Perovskite solar cell (PSC) technology is moving closer to commercialization, but the ecotoxicity of the solvents involved in perovskite processing remains a barrier. From the perspective of green chemistry and circular economy, we have pioneered the development of an environmentally friendly method for preparing alcohol‐based PSCs, which combines the advantages of green mixed‐alcohol solvents and lead acetate (Pb(Ac) 2 ). However, the photovoltaic performance usually deteriorates due to the sluggish ion diffusion and exchange during the conversion of Pb(Ac) 2 /perovskite. In this work, our study identifies that the slow iodine homogenization that occurs through I − diffusion into the initial Ac‐rich phase to replace Ac − , i.e., Ac − /I − exchange, will retard the overall conversion rate of Pb(Ac) 2 /perovskite. Herein, a multifunctional pore‐guiding additive, methylsulfonyl hydrazine (Ms‐Hz), is introduced into the Pb(Ac) 2 /alcohols precursor to simultaneously modulate the nanostructure of Pb(Ac) 2 films and passivate defects in perovskite. The resultant porous Pb(Ac) 2 scaffold can play a decisive role in improving the overall conversion rate. Consequently, the target MAPbI 3 PSCs achieves a champion power conversion efficiency (PCE) of 22.26% with enhanced stability, comparable to its toxic PbI 2 /DMF counterpart. This work demonstrates the potential of multifunctional foaming agents in developing high‐performance alcohol‐based PSCs.