Enabling Low‐Noise, High‐Detectivity, Stable, and Flexible Perovskite Mesh Nanowire Photodetectors by Phenylethylamine Iodine Doping Strategy

Abstract The poor stability, high noise, and low detectivity (D^*) of perovskite mesh nanowire (PMN) photodetectors (PDs) seriously hinder their practical applications. Here, a phenylethylamine iodine doping strategy (PIDS) is introduced to solve these problems. The PIDS leads to the formation of 2D perovskite PEA₂MA_x‐1Pb_xI_3x+1 (PEA = phenylethylamine, MA = methylamine) within MAPbI₃ PMN, which not only prevents water and oxygen erosion to thwart PMN degradation but also inhibits the transport of dark state carriers to reduce dark current. As a result, the noise, D^*, and stability of the PMN PD are simultaneously improved. The device exhibits low noise current (7.61 × 10⁻¹⁵ A Hz^−1/2) and high D^* of 3.2 × 10¹⁴ Jones, the highest D^* value for PMN PDs reported to date. Moreover, the unpacked device sustains 100% of its initial performance after 2880 h of storage in the air (45–55% humidity), enabling it as the most stable MAPbI₃ perovskite micro/nanostructure PD reported to date. Furthermore, the flexible device with PIDS exhibits comparable performance to that of the rigid device as well as great mechanical stability. Finally, the flexible device with PIDS demonstrates excellent optical imaging capability and a higher precision optical imaging potential than the commercial silicon photodiode S2386.