Investigation of Charge Transport Properties in a 2D Dion-Jacobson Halide Perovskite Based on Terphenyl Dications

Type II heterostructures formed by organic semiconducting ligands and inorganic layers in two-dimensional (2D) hybrid perovskites can offer separated charge transport channels for holes and electrons. In this work, we studied a new lead-based 2D Dion-Jacobson perovskite structure incorporating simple terphenyl diammonium salts as organic spacers. The investigations of the electronic and photophysical properties, combined with theoretical calculations, indicate that this 2D perovskite structure forms a type II heterostructure producing intercalated separate pathways for electrons and holes that can migrate within the inorganic and organic sublayers, respectively. The charge transport properties of this unusual type II 2D perovskite heterostructure have also been successfully investigated for the first time by the space charge limited current (SCLC) method, and maximum electron and hole mobilities based on single-crystal devices were evaluated to be 0.3 cm² V^-1 s^-1 and 7.0 × 10^-4 cm² V^-1 s^-1, respectively. This work gives valuable insights into the charge transport mechanisms of type II heterostructures and paves the way toward optoelectronic device applications for such Dion-Jacobson-type 2D perovskites.