Oriented Perovskite Growth Regulation Enables Sensitive Broadband Detection and Imaging of Polarized Photons Covering 300-1050 nm

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)(Sn0.5Pb0.5)(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)(Sn0.5Pb0.5)(5)I-16 crystal occurs in confined crystallographic orientation of the (202) facet upon the assistance of NH4SCN and NH4Cl, 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 approximate to 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 approximate to 3 x 10(8), linear dynamic range from 0.15 nW to 12 mW, noise current of 8.28 x 10(-13) A x Hz(-0.5), and specific detectivity of 1.53 x 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.

Automated summary

Traditional polarization-sensitive photodetectors have limitations due to complex fabrication processes, but a solution-processed polycrystalline film can achieve high resolution and speed for sensing polarized photons in the range of 300 to 1050 nm.