Nanoimprinted Quasi-2D Perovskites toward High-Performance Polarization-Sensitive Photodetectors

The demand for high-performance polarization-sensitive perovskite photodetectors (PSPPDs) has driven research to develop new materials that enable efficient light harvesting and polarization detection. Herein, a PSPPD based on nanoimprinted quasi-2D halide perovskite thin films with vertical gradient phase distribution is reported. The nanoimprinting method is utilized to create nanoscale linear patterns on the surface of the film. It enables polarized light detection and enhances absorption. According to the results of transient absorption analysis, a vertical gradient phase distribution along the longitudinal direction of quasi-2D perovskite (PEA)₂(MA)_n-1Pb_nI_3n+1 (PEA⁺ = C₆H₅CH₂CH₂NH₃⁺, MA⁺ = CH₃NH₃⁺, n = 3) is confirmed, which facilitates efficient carrier transfer and separation, leading to improved device performance. These PSPPDs demonstrate outstanding photo-response with a large responsivity of ≈90 A W⁻¹ and a high detectivity reaching the order of 10¹² Jones. The photoluminescence of the quasi-2D perovskite film exhibits an anisotropy ratio of 2.05, and the PSPPD reaches a polarization sensitivity of 1.68. These findings offer insight into the feasibility of developing perovskite materials for PSPPDs, which have potential applications in imaging, sensing, and communication technologies.