Improved Performance and Stability of Perovskite Solar Modules by Regulating Interfacial Ion Diffusion with Nonionic Cross-Linked 1D Lead-Iodide

Long-term stability has become the major obstacle for the successful large-scale application of perovskites devices. Owing to the ionic nature of metal-halide perovskites, the interfacial ion diffusion can induce irreversible degradation under operational conditions, which presents a great challenge to realize stable perovskite solar modules. Here, a diphenylphosphine oxide compound, ethane-1,2-diylbis(diphenylphosphine oxide) (DPPO) is introduced to coordinate with lead iodide and form a cross-linked 1D Pb 3 I 6 -DPPO (1D-PbI 2 ) complex. These judiciously designed cross-linked nonionic low-dimensional lead halide/organic adducts can passivate the defects of perovskite while acting as a robust ion diffusion barrier, thus significantly improving the electronic quality and intrinsic stability of perovskite films. As a result, high-performance inverted (p-i-n) solar modules with a champion efficiency approaching 19% (a certified stabilized efficiency of 17.8%) for active device areas above 17 cm 2 without the use of antisolvents, accompanied by outstanding operational stability under heat stress and continuous illumination are achieved.