Single Layer of Crown\nEther Enables Efficient, Stable,\nand Pb Leakage-Free Inverted Perovskite Solar Cells

Significant challenges in ensuring long-term stability,\naddressing\nenvironmental safety issues, and improving efficiency have hindered\nthe commercialization of inverted Pb-based halide perovskite solar\ncells (PeSCs). One reasonable approach to addressing these issues\nis to place an effective buffer layer between the perovskite active\nlayer and the electrode. In this study, we demonstrate the use of\ncrown ether, di-<i>tert</i>-butyl dibenzo-18-crown-6, as\na single buffer layer to improve the efficiency, long-term stability,\nand environmental safety of PeSCs for the first time. The crown ether\nbuffer layer suppressed Ag diffusion from the Ag metal electrodes,\nthereby improving the performance and lifetime of the device. In addition,\nit effectively captures Pb ions that may leak into the environment\nduring the whole lifetime of devices, thereby enhancing the environmental\nsafety of PeSCs. Furthermore, PeSCs incorporating crown ethers as\nbuffer layers demonstrated enhanced stability in a nitrogen atmosphere\nand achieved a high power conversion efficiency of 22.8%. Consequently,\nthis crown ether buffer layer offers an effective and straightforward\nstrategy capable of achieving efficient, stable, and environmentally\nsafe PeSCs.