2D Hybrid Perovskites Employing an Organic Cation Paired with a Neutral Molecule

Two-dimensional (2D) hybrid perovskites harness the chemical and structural versatility of organic compounds. Here, we explore 2D perovskites that incorporate both a first organic component, a primary ammonium cation, and a second neutral organic module. Through the experimental examination of 42 organic pairs with a range of functional groups and organic backbones, we identify five crystallization scenarios that occur upon mixing. Only one leads to the cointercalation of the organic modules with distinct and extended interlayer spacing, which is observed with the aid of X-ray diffraction (XRD) pattern analysis combined with cross-sectional transmission electron microscopy (TEM) and elemental analysis. We present a picture in which complementary pairs, capable of forming intermolecular bonds, cocrystallize with multiple structural arrangements. These arrangements are a function of the ratio of organic content, annealing temperature, and substrate surface characteristics. We highlight how noncovalent bonds, particularly hydrogen and halogen bonding, enable the influence over the organic sublattice in hybrid halide perovskites.

Automated summary

Two-dimensional hybrid perovskites incorporating organic compounds exhibit multiple structural arrangements depending on the ratio of organic content, annealing temperature, and substrate surface characteristics. Through experimental examination, researchers identify five crystallization scenarios, with only one leading to the cointercalation of organic modules. Noncovalent bonds, such as hydrogen and halogen bonding, play a crucial role in influencing the organic sublattice in these hybrid perovskites.