Polarization‐Sensitive Photodetector Using Patterned Perovskite Single‐Crystalline Thin Films

Abstract Hybrid organic–inorganic perovskite single crystals, compared with their polycrystalline counterparts in thin films, are free from grain boundaries and have fewer defects, and therefore are promising in high‐performance optoelectronic devices. Recently, the crystal‐structure anisotropy in perovskites has been utilized to achieve polarization‐sensitive photodetectors. Here, it is shown that under 532 nm linearly polarized illumination, although MAPbBr₃ (MA=CH₃NH₃⁺¹) single crystals possess weak in‐plane anisotropy, nanogratings made on the crystal surface lead to high polarization photodetection sensitivity of ≈2.2 comparable with that of the isotropic perovskite crystals and nanowires, while enhancing both the photodetection responsivity and external quantum efficiency. The surface nanopattern induced polarization sensitivity may find interesting applications in future optoelectronic devices.