Unified Approach to Sensitive and Fast Perovskite Photodetectors Featuring an Ultrawide Linear Dynamic Range

Abstract Organic–inorganic halide perovskite photodetectors (PDs) offer excellent performance, yet some critical parameters, like linear dynamic range (LDR) and low‐light detection, remain underexplored. Here, a formamidinium lead iodide (FAPbI 3 ) perovskite PD is reported with a wide LDR and enhanced low‐light sensitivity. Two hole‐transport layers (HTLs), spiro‐OMeTAD and C8‐BTBT, are employed to systematically investigate their effects on the PD's key performance parameters. While spiro‐OMeTAD provides superior charge extraction, it requires doping, potentially compromising long‐term stability. In contrast, the small molecule‐based semiconductor C8‐BTBT provides greater stability and suitable hole mobility. Both HTL‐based devices exhibit excellent light sensitivity, detecting light down to a few pW cm −2 . Devices with doped HTL exhibit a wide LDR reaching 200 dB. Furthermore, theoretical simulations highlight the critical impact of conductivity, energy level alignment, and ion migration on the PD's performance. This work elucidates the HTL's role in the device performance, aiding in selecting an appropriate HTL for specific applications.