Recently, lead halide perovskites have shown great potential in the photodetection field. Unfortunately, the existence of toxic lead elements restricts their practical application. Herein, high-quality 1D lead-free crystals Rb₂CuX₃ (X = Cl, Br) are successfully synthesized in an acidic medium. Rb₂CuCl₃ and Rb₂CuBr₃ display violet photoluminescence emission peaks at 401 and 388 nm with a high exciton lifetime of 12.78 and 59.67 µs, respectively, which is due to self-trapped excitons (STE). Furthermore, a photodetector is fabricated to detect harmful UVC radiation with Rb₂CuBr₃ as a light absorber. The proposed photodetector has a responsivity of 0.92 mA W⁻¹ and a specific detectivity of 1.57 × 10⁹ Jones with a fast response speed of 2.67/2.70 µs for rise/fall time, respectively. In addition, both the samples show good stability against open air, and continuous ultraviolet light (254 nm), as well as good thermal stability which is necessary for device fabrication. Thus, the present study suggests that stable, non-toxic, and environment-friendly Rb₂CuX₃ (X = Cl, Br) can be a promising candidate for future UVC optoelectronic devices.

中文翻译：

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用于 UVC 光电探测器的无铅全无机卤化铷铜 Rb2CuX3 （X = Cl， Br）


最近，卤化铅钙钛矿在光探测领域显示出巨大的潜力。不幸的是，有毒铅元素的存在限制了它们的实际应用。在此，在酸性介质中成功合成了高质量的 1D 无铅晶体 Rb₂CuX₃ （X = Cl， Br）。Rb₂CuCl₃ 和 Rb₂CuBr₃ 在 401 nm 和 388 nm 处显示紫色光致发光发射峰，具有 12.78 和 59.67 μs 的高激子寿命，这是由于自捕获激子 （STE） 造成的。此外，还制造了一种光电探测器来检测有害的 UVC 辐射，其中 Rb₂CuBr₃ 作为光吸收剂。所提出的光电探测器的响应度为 0.92 mA ^W-1，特异性探测率为 1.57 × 10⁹ Jones，上升/下降时间的快速响应速度分别为 2.67/2.70 μs。此外，这两个样品在露天和连续紫外光 （254 nm） 下都表现出良好的稳定性，以及器件制造所必需的良好热稳定性。因此，本研究表明，稳定、无毒、环保的 Rb₂CuX₃ （X = Cl， Br） 可以成为未来 UVC 光电器件的有前途的候选者。