Multifunctional Aminoglycoside Antibiotics Modified SnO2 Enabling High Efficiency and Mechanical Stability Perovskite Solar Cells

Abstract SnO2 as an electron transport layer (ETL) has been widely used in regular planar perovskite solar cells (PSCs) owing to its high optical transmittance, less photocatalytic activity, and low‐temperature processing. However, SnO2‐based PSCs still face many challenges which greatly impair their efficiency and stability of PSCs. Herein, a novel and effective multifunctional modification strategy is proposed by incorporating streptomycin sulfate (STRS) molecules with multiple functional groups into SnO2 ETL. STRS can significantly suppress SnO2 nanoparticle agglomeration, improve the electronic property of SnO2, as well as reduce nonradiative recombination. At the same time, interfacial residual tensile stress is released and the interfacial energy level alignment becomes more matched. As a result, the STRS‐modified PSCs achieve a higher efficiency of 22.89% compared to 20.61% of the control device and exhibit a hysteresis‐free feature. The humidity and thermal stability of PSCs based on STRS‐SnO2 are significantly improved. Furthermore, the efficiency of flexible devices increased from 19.74% to 20.79%, and the devices still maintain >80% of initial PCE after 4500 bending cycles with a bend radius of 5 mm. This study provides a low‐cost, facile, and efficient strategy for achieving high efficiency and stability in PSCs.