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.