Scalable Fabrication of Efficient Perovskite Solar Modules on Flexible Glass Substrates

Perovskite materials are good candidates for flexible photovoltaic applications due to their strong absorption and low‐temperature processing, but efficient flexible perovskite modules have not yet been realized. Here, a record efficiency flexible perovskite solar module is demonstrated by blade coating high‐quality perovskite films on flexible Corning Willow Glass using additive engineering. Ammonium chloride (NH 4 Cl) is added into the perovskite precursor solution to retard the nucleation which prevents voids formation at the interface of perovskite and glass. The addition of NH 4 Cl also suppresses the formation of PbI 2 and reduces the trap density in the perovskite films. The implementation of NH 4 Cl enables the fabrication of single junction flexible perovskite solar devices with an efficiency of 19.72% on small‐area cells and a record aperture efficiency of 15.86% on modules with an area of 42.9 cm 2 . This work provides a simple way to scale up high‐efficiency flexible perovskite modules for various applications.