Excitons in ultrathin organic-inorganic perovskite crystals

The new family of layered organic-inorganic perovskite crystals (OIPCs) is a unique addition to the set of available 2D materials. It is a crystalline inorganic solid that is surrounded by well-ordered organic ligands, both of which can be modified separately. This hybrid character endows the material with an unusual degree of tunability and flexibility. Here, the authors present their results on the synthesis and extensive characterization of 2D OIPC single-crystalline bilayers of (C₄H₉NH₃)₂PbI₄. These materials could significantly expand the range of van der Waals heterostructures that can be produced by their combination with, e.g., graphene, h-BN layers, transition metal dichalcogenide layers, etc.