Enhanced Weak-Light Detection of Perovskite Photodetectors through Perovskite/Hole-Transport Material Interface Treatment.

Enhancement in weak-light detection and other photodetection properties was observed for organic-inorganic halide perovskite photodetectors as a result of benzylammonium iodide (BzAI) treatment at the methylammonium lead triiodide (MAPbI) and hole-transport layer (HTL) interface. After treatment, growth of the two-dimensional Ruddlesden-Popper perovskite phase was observed at the MAPbI surface, which shifted the overall surface work function upwards and thus effectively facilitated charge transfer across the MAPbI/HTL interface. As a result, the fully fabricated device with 10 mg/mL (BzAI/isopropanol) treatment exhibited shorter rise time () and decay time () of 53 and 38 μs, respectively, compared to and of 214 and 120 μs, respectively, for the pristine MAPbI sample. In addition, the BzAI-treated device exhibited larger linearity compared to the pristine MAPbI sample, demonstrating a high and stable specific detectivity of 1.49 × 10 to 2.14 × 10 Jones under incident light intensity of 10 to 10 mW/cm, respectively.