In Situ Encapsulated Moiré Perovskite for Stable Photodetectors with Ultrahigh Polarization Sensitivity

Abstract Nanostructures provide a simple, effective, and low‐cost route to enhance the light‐trapping capability of optoelectronic devices. In recent years, nano‐optical structures have been widely used in perovskite optoelectronic devices to greatly enhance the device performance. However, the inherent instability of perovskite materials hinders the practical application of these nanostructured optoelectronic devices. Here, in situ encapsulated moiré lattice perovskite photodetectors (PDs) by two nanograting‐structured soft templates with relative rotation angles is fabricated. The confinement growth of the two nanograting templates leads to crystal growth with moiré lattice structure, which improves the light‐harvesting ability of the perovskite crystal, thereby improving the device performance. The PD exhibits responsivity to 1026.5 A W⁻¹. The Moiré lattice‐perovskite‐based PD maintained 95% of the initial performance after 223 days. After being continuously sprayed with water moist for 180 min, the performance is maintained at 95.7% of its initial level. The nanograting structure endows the device with high polarization sensitivity of I_max/I_min as high as 9.1.