Template-confined growth of copper halides micro-wire arrays for highly polarization-sensitive deep-ultraviolet photodetectors with a polarization sensitivity of 4.45

Polarization-sensitive detectors operating in the deep-ultraviolet (DUV) region have been favored for their great meaning in the field of biological tissue morphology, image display systems and sensors. The advantages of intrinsic DUV light absorption, low-symmetry crystal structure and morphology anisotropy make Cs₃Cu₂I₅ micro-wire arrays the perfect choice for polarization-sensitive DUV photodetection. In this work, we demonstrate a polarization-sensitive DUV photodetector developed from the Cs₃Cu₂I₅ micro-wire arrays, which were prepared by a microchannel-confined crystallization strategy, and the optical and optoelectronic anisotropy of Cs₃Cu₂I₅ micro-wire arrays with adjustable sizes were systematically investigated. Owing to the high crystallinity and good carrier transportation ability of the Cs₃Cu₂I₅ micro-wires, the photodetector exhibits a large responsivity of ∼ 23.6 A/W and a fast response speed of 2.9/370.7 μs. Based on the intrinsic anisotropy of the asymmetric structure and external morphology anisotropy of the Cs₃Cu₂I₅ micro-wires, the photodetector exhibits an ultra-high polarization sensitivity of 4.45. Moreover, the photodetector can keep nearly the identical capability even after 40 days exposure in the open air. This work reveals the potential of Cs₃Cu₂I₅ as environmentally-friendly and stable candidates for polarization-sensitive DUV photodetectors, opening up possibilities for developing polarized DUV imaging technology.