High performance flexible Sn-Pb mixed perovskite solar cells enabled by a crosslinking additive

Flexible perovskite solar cells (PSCs) have drawn increasing attention due to their promising applications for wearable electronics and aerospace applications. However, the efficiency and stability of flexible PSCs still lag behind their rigid counterparts. Here, we use N,N-dimethyl acrylamide (DMAA) to in situ synthesize cross-linking polymer for flexible Sn–Pb mixed PSCs. DMAA can gather at grain boundary as a scaffold to regulate the crystallization of perovskite and reduce defects. The rigid and flexible Sn–Pb mixed PSCs showed efficiencies of 16.44% and 15.44%, respectively. In addition, the flexible Sn–Pb mixed PSCs demonstrated excellent bending durability, which retained over 80% of the original efficiency after 5000 bending cycles at a radius of 5 mm.