Multiple Stabilization Effects of Benzylhydrazine on Scalable Perovskite Precursor Inks for Improved Perovskite Solar Cell Production

Perovskite precursor inks suffer various forms of degradation, such as iodide anion oxidation and organic cation breakdown, hindering reliable perovskite solar cell manufacturing. Here we report that benzylhydrazine hydrochloride (BHC) not only retards the buildup of iodine as previously reported but also prevents the breakdown of organic cations. Through investigating BHC and iodine chemical reactions, we elucidate protonation and dehydration mechanisms, converting BHC to harmless volatile compounds, thus preserving perovskite film crystallization and solar cell performance. This inhibition effect lasts nearly a month with minimal BHC, contrasting control inks without BHC where organic cations fully react in less than a week. This enhanced understanding, from additive stabilization to end products, promises improved perovskite solar cell production reliability. A method of stabilizing perovskite ink is proposed. This method uses benzylhydrazine hydrochloride (BHC) to stabilize the organic cations of perovskite ink, and remove harmful water impurities, while also reducing iodine back to iodide as has already been discovered. The downstream products of BHC and iodine are investigated via 1D and 2D NMR spectroscopy and found to be chemically benign. All scalable perovskite solar cells are made with BHC ink and found to have nearly 20 % efficiency.