High‐Performance Flexible Perovskite Solar Cells Enabled by Low‐Temperature ALD‐Assisted Surface Passivation

Abstract Flexible perovskite solar cells (PeSCs) hold great potential as a leading technology for large‐scale roll‐to‐roll production of highly efficient renewable energy sources. To achieve long‐term bendability and competitive photovoltaic properties for flexible PeSCs, an efficient strategy is reported for a fully indium‐free flexible composite electrode, consisting of solution‐processed silver nanowires (AgNWs) conductive network, a sol–gel‐derived ZnO protective layer for smoothing the surface, and an atomic‐layer‐deposited TiO 2 passivation layer for eliminating the perovskite decomposition. The synergetic interplay of this electrode stack results in good electrical conductivity, optical transparency, mechanical robustness, and low‐temperature processability. With collective optimization of this composite electrode, flexible PeSCs on plastics realize a power conversion efficiency of 17.11%, which is comparable to that of conventional indium‐tin‐oxide‐based device (18.26%). Moreover, flexible PeSCs using this composite electrode are repeatedly bendable, retaining 77% of their initial efficiency after 2000 bending cycles at a radius of 6 mm. Because of the ease of use and remarkable improvement in efficiency, this flexible composite electrode will help to enable the low‐cost roll‐to‐roll processing of flexible PeSCs.