Perovskite Ink Engineering for Scalable Process Based Solar Cells

Perovskite solar cells (PSCs) with huge attention based on high efficiency are now establishing as one of the most promising photovoltaic (PV) technologies. Nowadays, only a few researches for upscaling and commercialization through eco-friendly solvent and process approaches are being attempted. Herein, we introduced for a rheological engineering-based locally supersaturated perovskite ink (LSPI) strategy for slot-die process-based PSC which can be suitable for roll-to-roll systems. Here, a perovskite precursor ink with a low-toxic dimethyl sulfoxide (DMSO) single solvent was applied, and a small amount of 1,2- Dichlorobenzene (DCB) was used as an additive to modulate the rheological properties of the ink. The addition of DCB decreased the high surface tension of the DMSO-based ink to enable uniform wet-film formation and produce locally supersaturated colloids (i.e., perovskite seeds that helped growth into dense and large grains by heterogeneous nucleation with low Gibbs-free energy). As a result, this LSPI approach enabled slot-die coated PSCs with higher efficiency. The devices also showed better stability. These studies could be highly beneficial for low-cost, high efficiency, and high stability perovskite solar cell applications.