Liang Haixia, Zhang Junyao, Zhao Xinglei, Ye Yi, Liu Xu, Li Li, Yang Gonghai, Huang Jia
School of Materials Science and Engineering, Tongji University, Shanghai, 201804, P. R. China.
State Key Laboratory of Petroleum Pollution Control, CNPC Research Institute of Safety and Environmental Technology, Beijing, 102206, P. R. China.
Small. 2025 May;21(21):e2501140. doi: 10.1002/smll.202501140. Epub 2025 Apr 3.
Near-infrared (NIR) organic photodetectors (OPDs) have significant potential in the development of night vision, optical communication, and image-sensing systems. However, most of them require external energy consumption, and particularly the investigation focuses on weak light detection in the NIR region at or beyond 1000 nm remains limited. In this study, self-powered OPDs with a PCE10:COTIC-4F organic bulk heterojunction as the photoactive layer are designed, which are capable of responding to an ultra-weak light signal of 6.3 pW cm at 1000 nm, demonstrating a significantly low level in comparison to currently reported OPDs. In addition, the OPDs also exhibit other outstanding photodetection performance, including large I/I ratio of 3.47 × 10, high responsivity of 1.50 A W, and detectivity of 3.17 × 10/1.80 × 10 Jones (evaluated by dark/noise current methods). Furthermore, the unencapsulated OPDs demonstrate almost no obvious attenuation in the air during a 224-day test and in the aging environment during a 67-day test. More importantly, the self-powered OPDs demonstrate the potential for flexible electronics, NIR imaging, and NIR selectivity with visible-blind characteristic. The development of self-powered OPDs provides an accessible and viable route for advancing weak NIR detection.
近红外（NIR）有机光电探测器（OPD）在夜视、光通信和图像传感系统的发展中具有巨大潜力。然而，它们中的大多数需要外部能量消耗，特别是在1000nm及以上的近红外区域对弱光检测的研究仍然有限。在本研究中，设计了以PCE10:COTIC-4F有机本体异质结作为光活性层的自供电OPD，其能够响应1000nm处6.3 pW cm的超弱光信号，与目前报道的OPD相比，该水平显著较低。此外，这些OPD还表现出其他出色的光电探测性能，包括3.47×10的大I/I比、1.50 A W的高响应度以及3.17×10/1.80×10琼斯的探测率（通过暗/噪声电流方法评估）。此外，未封装的OPD在224天的空气测试和67天的老化环境测试中几乎没有明显衰减。更重要的是，自供电OPD展示了在柔性电子、近红外成像和具有可见光盲特性的近红外选择性方面的潜力。自供电OPD的发展为推进弱近红外检测提供了一条可行且可及的途径。
