Highly efficient and stable perovskite solar cells based on E-beam evaporated SnO2 and rational interface defects passivation

Abstract Owing to the significant roles in balancing carrier transport, bandgap alignment, and perovskite crystallization, realizing high‐quality electron transport layers (ETLs) and their effective electronic contact with the perovskite photoactive layer is crucial for future commercialization of perovskite solar cells (PSCs). Here, a high‐quality SnO2 ETL is firstly deposited at room temperature via the low‐cost electron beam evaporation (E‐beam) technology to help achieve an impressive PCE of 18.88% for rigid PSCs and a PCE of 15.73% for flexible devices. Then we introduced a novel passivating ligand molecule, 11 Maleimidoundecanoic acids (11MA), to help induce functional defects passivation at the interface of SnO2/Perovskite to coordinate with Pb2+ in perovskite and Sn4+ in SnO2 via the functional groups (‐C = O, ‐COOH). As a result, 11MA could help achieve the best PCE of 20.94% with negligible hysteresis for rigid devices. Also, doping 11MA in the perovskite photoactive layer further enhanced the PCE to 22.08% with much improved 2000 hours ambient stabilities. Finally, we fabricated different large‐area rigid devices (10, 40, 100, and 600 mm2) toward speeding up the commercialization of PSCs by industrial E‐beam technology and rational defects passivation strategies.