Infiltration of methylammonium metal halide in highly porous membranes using sol-gel-derived coating method

Abstract Organic–inorganic halide perovskites (OIHPs) has emerged as promising optoelectronic materials for solar cells and light-emitting diodes. OIHPs are usually coated on a flat surface or mesoporous scaffold for the applications. Herein, we report a facile sol-gel-derived solution route for coating methylammonium lead iodide (MAPbI 3 ) perovskite layers onto various nanoporous structures. We found that lead-acetate solution has superior infiltration property onto surface of oxide membranes, and it can easily be converted to MAPbI 3 by sequential transform to PbO, PbI 2 , and finally MAPbI 3 . Excellent pore-filling and full coverage of the nanostructures with the final MAPbI 3 perovskite material are demonstrated via this sol-gel-derived solution route, using mesoporous TiO 2 , TiO 2 nanorods, and high-aspect ratio nanopores in anodic aluminum oxide membranes. Given that this sol-gel-based method fills nanopores better than other conventional coating methods for OIHPs, this method may find wide applications in nanostructured OIHPs-based optoelectronic systems.