摘要
Photodetectors selective to the polarization empower breakthroughs in sensing technology for target identification. However, the realization of polarization-sensitive photodetectors based on intrinsically anisotropic crystal structure or extrinsically anisotropic device pattern requires complicated epitaxy and etching processes, which limit scalable production and application. Here, solution-processed PEA 2 MA 4 (Sn 0.5 Pb 0.5 ) 5 I 16 (PEA= phenylethylammonium, MA= methylammonium) polycrystalline film is probed as photoactive layer toward sensing polarized photon from 300 to 1050 nm. The growth of the PEA 2 MA 4 (Sn 0.5 Pb 0.5 ) 5 I 16 crystal occurs in confined crystallographic orientation of the (202) facet upon the assistance of NH 4 SCN and NH 4 Cl, enhancing anisotropic photoelectric properties. Therefore, the photodetector achieves a polarization ratio of 0.41 and dichroism ratio ( I max / I min ) of 2.4 at 900 nm. At 520 nm, the I max / I min even surpasses the one of the perovskite crystalline films, 1.8 and ≈1.2, respectively. It is worth noting that the superior figure-of-merits possess a response width of 900 kHz, I on / I off ratio of ≈3 × 10 8 , linear dynamic range from 0.15 nW to 12 mW, noise current of 8.28 × 10 −13 A × Hz −0.5 , and specific detectivity of 1.53 × 10 12 Jones, which demonstrate high resolution and high speed for weak signal sensing and imaging. The proof of concept in polarized imaging confirms that the polarization-sensitive photodetector meets the requirements for practical application in target recognition.
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