Two-Dimensional Metal Halide Perovskites Created by Binary Conjugated Organic Cations for High-Performance Perovskite Photovoltaics.

Studies indicated that two-dimensional (2D) metal halide perovskites (MHPs) embodied with three-dimensional (3D) MHPs were a facile way to realize efficient and stable perovskite solar cells (PSCs) and perovskite photodetectors (PPDs). Here, high-performance PSCs and PPDs, which are based on 2D/3D MHPs bilayer thin films, where the 2D MHPs are created by binary conjugated organic cations, are reported. Systemically studies reveal that the above novel 2D/3D MHPs bilayer thin films possess an enlarged crystal size, balanced charge transport, reduced charge carrier recombination, smaller charge-transfer resistance, and accelerated charge-extraction process compared to the 2D/3D MHPs bilayer thin films, where the 2D MHPs are created by a single conjugated organic cation.