Organic–inorganic hybrid perovskite has attracted extensive research due to its excellent optoelectronic properties and is a competitive candidate material for a new generation of photodetectors. However, lateral structure photodetectors based only on perovskite active materials still present moderate performance and poor stability. Herein, lateral structure formamidinium‐based perovskite FA0.9Cs0.1PbI3 photodetectors are reported which are modified by a solution‐processed organic semiconductor 2,7‐dioctyl[1]benzothieno[3,2‐b][1]benzothiophene (C8‐BTBT) layer for improved photosensitive performance and ambient/flexibility stability. High‐mobility organic semiconductor C8‐BTBT serves as an efficient hole transport layer that fills the grain boundaries and gaps of the FA0.9Cs0.1PbI3 film, enabling rapid extraction and transport of the photo‐generated carriers from the perovskite to the electrodes, resulting in enhanced photosensitive performance of the photodetector. Compared with the original device, the C8‐BTBT‐modified photodetector exhibits dramatically improved performance with a best responsivity of 1278 mA W−1, specific detectivity of 1.58 × 1012 Jones, external quantum efficiency of 298%, and fall time of 14.09 ms, which is 10.84 times less than 152.76 ms of the pure perovskite device. Moreover, the C8‐BTBT film acts as a protective layer for the FA0.9Cs0.1PbI3 film because of its good air stability and effective coverage, which significantly improves the ambient stability of the perovskite photodetector compared with the original device, increasing photocurrent retention from 2.5% to 61.5% or 81.5% at different humidity after 6 days. Furthermore, the C8‐BTBT‐modified perovskite photodetector exhibits outstanding flexibility performance, with only a 5% reduction in photocurrent under bending and almost no change after 200 bending cycles, while those of the pristine perovskite device have degraded to ≈80% and ≈75% under the same conditions, respectively. This study provides a facile and effective solution‐processed‐based strategy for constructing high‐performance and stable perovskite photodetectors.

中文翻译：

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通过溶液处理的 C8-BTBT 改性改进甲脒基钙钛矿光电探测器的性能

有机-无机杂化钙钛矿因其优异的光电性能而吸引了广泛的研究，是新一代光电探测器的有竞争力的候选材料。然而，仅基于钙钛矿活性材料的横向结构光电探测器仍然表现出较差的性能和较差的稳定性。在此，横向结构甲脒基钙钛矿FA0.9CS0.1碘化铅3据报道，光电探测器通过溶液处理的有机半导体 2,7-二辛基[1]苯并噻吩并[3,2-b][1]苯并噻吩 (C8-BTBT) 层进行修饰，以提高光敏性能和环境/柔性稳定性。高迁移率有机半导体C8-BTBT作为有效的空穴传输层，填充FA的晶界和间隙0.9CS0.1碘化铅3薄膜，能够快速提取光生载流子并将其从钙钛矿传输到电极，从而增强光电探测器的光敏性能。与原始设备相比，C8-BTBT 改进的光电探测器表现出显着提高的性能，最佳响应率为 1278 mA W−1，比探测度为1.58×1012Jones 的外量子效率为 298%，下降时间为 14.09 ms，比纯钙钛矿器件的 152.76 ms 减少了 10.84 倍。此外，C8-BTBT薄膜充当FA的保护层0.9CS0.1碘化铅3薄膜因其良好的空气稳定性和有效覆盖性，与原始器件相比显着提高了钙钛矿光电探测器的环境稳定性，6天后不同湿度下的光电流保留率从2.5%提高到61.5%或81.5%。此外，C8-BTBT修饰的钙钛矿光电探测器表现出出色的柔性性能，弯曲下光电流仅减少5％，并且在200次弯曲循环后几乎没有变化，而原始钙钛矿器件的光电流已退化至约80％和约75％相同条件下分别为%。这项研究为构建高性能且稳定的钙钛矿光电探测器提供了一种简便有效的基于溶液处理的策略。