1,8-Octanedithiol Additive Engineering for Improved Perovskite Adduct Phase Control in Durable and Efficient Photodetector

Abstract

To secure the stable driving characteristics of photodetector, the durability of perovskite photosensitive layer is required to be improved. In this paper, a stabilizing strategy with anti-solvent additive is proposed via 1,8-octanedithiol as Lewis acid-base interaction accelerator. It includes the rapid perovskite phase conversion, which induces the coordination bond between double thiol ends of the additive and Pb2+ of MAPbI3. The stabilized film has a narrow roughness deviation, increased average grain size of ∼228.33 nm, and the least hydrophilic surface energy of 62.26 mJ/m2. Based on the synergic effect of it, the perovskite photodetector is fabricated with ∼252 nm MAPbI3 layer. The optimized photodetector has a dark current density of 2.00 × 10−7 A/cm2 under −0.1 V bias. Also, a responsivity of 0.366 A/W and detectivity of 1.45 × 1012 cmHz1/2W−1 is found under 680 nm. The ∼90% maintained detectivity after ∼260 h suggest the possibility of the durable perovskite photodetector operation. © 2023 Elsevier B.V.