Low‐dimensional organic–inorganic hybrid perovskites with controllable morphologies are attractive for high‐performance optoelectronic devices. In particular, the 1D organic–inorganic hybrid perovskite nanowires/nanobelts are promising for flexible photodetectors due to high photoresponsivity and strain endurance capability. Herein, a novel and large‐scale synthesis of (C₄H₉NH₃)₂PbBr₄ organic–inorganic hybrid perovskite nanobelt achieved by the potassium ions assisted controllable crystal growth during the precipitation process in solutions is reported. The obtained (C₄H₉NH₃)₂PbBr₄ perovskite nanobelts exhibit high‐efficient photoluminescence and superior stability under ambient conditions. Furthermore, these nanobelts are used as photoresponsive materials to fabricate flexible photodetectors, which show much higher switching ratio than that of photodetectors based on (C₄H₉NH₃)₂PbBr₄ microplatelets. Attractively, after repeated bending for 1000 times, the nanobelt‐based photodetector only shows less than 10% decay in switching ratio in contrast to at least 40% of switching ratio decay for the microplatelets‐based photodetector. The reported potassium ion assisted large‐scale synthesis of (C₄H₉NH₃)₂PbBr₄ nanobelts paves a new avenue for the application of organic–inorganic hybrid perovskites in flexible optoelectronic devices.

中文翻译：

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钾离子辅助合成有机-无机杂化钙钛矿纳米带，用于稳定且灵活的光电探测器。

具有可控形态的低维有机-无机杂化钙钛矿对高性能光电器件具有吸引力。特别是，一维有机-无机杂化钙钛矿纳米线/纳米粒子由于具有高的光响应性和耐应变能力，因此有望用于柔性光电探测器。本文报道了一种新型的，大规模合成的（C ₄ H ₉ NH ₃）₂ PbBr ₄有机-无机杂化钙钛矿纳米带，其通过钾离子辅助溶液中沉淀过程中的可控晶体生长而实现。得到的（C ₄ H ₉ NH ₃）₂ PbBr ₄钙钛矿纳米带在环境条件下具有高效的光致发光性和出色的稳定性。此外，这些纳米带被用作光响应材料以制造柔性光电探测器，该柔性光电探测器显示出比基于（C ₄ H ₉ NH ₃）₂ PbBr ₄微片的光电探测器更高的转换率。有吸引力的是，在反复弯曲1000次之后，基于纳米带的光电探测器的开关比衰减仅不到10％，而基于微血小板的光电探测器的开关比衰减至少为40％。报道的钾离子辅助大规模合成（C ₄ H ₉ NH ₃）₂ PbBr ₄纳米带为有机-无机杂化钙钛矿在柔性光电器件中的应用开辟了一条新途径。