Silicon has been the most widely used material for broadband photodetectors. However, the weak response in ultraviolet (UV), especially in deep-UV region, and the large dark current are still their critical drawbacks for practical applications. In this study, a strategy of decorating Cs₃Cu₂I₅ nanocrystals (NCs) on Si nanowire arrays (NWAs) to form a hybrid structure was proposed to overcome the above two issues. Because of the wide and direct bandgap of Cs₃Cu₂I₅ with intrinsic UV light absorption, the photodetection ability of the hybrid detector in UV region was substantially enhanced owing to the efficient down-conversion of the UV incident light. Moreover, driven by a designed Schottky junction from asymmetric electrodes, the hybrid detector can be operated without external power supply. Typically, at 265 nm light excitation, the Si NWA-Cs₃Cu₂I₅ NCs hybrid device achieved a high photoresponsivity of 83.6 mA W⁻¹, a specific detectivity of 2.1 × 10¹² Jones, and a large on/off ratio of 3.72 × 10³ at 0 V, nearly 350 times higher than the bare Si NWA device. More importantly, the unencapsulated photodetector demonstrates an outstanding operational stability over the aging test for 10 h, and can endure a high humidity (75%, 7 days) and a long-term storage for 300 days in air ambient. Since the different deep-UV light sensitivity of the devices modified with/without Cs₃Cu₂I₅ NCs, a monolithically deep-UV light recognition system was therefore fabricated. It is anticipated that the present strategy provides a new avenue for the preparation of UV-enhanced broadband photodetectors, opening up opportunities for development of integrated optoelectronic systems in the future.

硅一直是宽带光电探测器使用最广泛的材料。然而，在紫外线（UV）中，特别是在深紫外线区域中的响应较弱，以及大的暗电流仍然是其在实际应用中的关键缺点。在这项研究中，提出了一种在Si纳米线阵列（NWAs）上装饰Cs ₃ Cu ₂ I ₅纳米晶体（NCs）以形成杂化结构的策略，以克服上述两个问题。由于Cs ₃ Cu ₂ I _5的带隙宽而直接通过固有的紫外光吸收，由于紫外入射光的有效下转换，混合探测器在紫外区域的光电探测能力大大增强。此外，由非对称电极设计的肖特基结驱动，无需外部电源即可操作混合检测器。通常，在265 nm的光激发下，Si NWA-Cs ₃ Cu ₂ I ₅ NCs混合器件实现了83.6 mA W ^-1的高光响应性，2.1×10 ¹² Jones的比检测率和大的开/关比。 3.72×10 ³ 在0 V时，比裸Si NWA器件高近350倍。更重要的是，未封装的光电探测器在老化测试中表现出出色的操作稳定性，可持续10小时，并且可以在高湿度（75％，7天）的环境下在空气中长期保存300天。由于使用/不使用Cs ₃ Cu ₂ I ₅ NC修改的器件的深紫外光灵敏度不同，因此制造了单片深紫外光识别系统。可以预期，目前的策略为紫外线增强型宽带光电探测器的制备提供了新途径，为将来开发集成光电系统开辟了机会。