Yan Tingting, Cai Sa, Hu Zijun, Li Ziqing, Fang Xiaosheng
Department of Materials Science, Fudan University, Shanghai 200433, P. R. China.
Department of Materials Science, Institute of Optoelectronics, Fudan University, Shanghai 200433, P. R. China.
J Phys Chem Lett. 2021 Oct 14;12(40):9912-9918. doi: 10.1021/acs.jpclett.1c03090. Epub 2021 Oct 6.
TiO-based photodetectors (PDs) have been hotspots in recent years for their excellent thermal stabilities and optoelectronic performance under ultraviolet (UV) light. However, the high dark current caused by defects in TiO films has limited the detectivity () of these PDs. Here, the dark current of a TiO-based PD was effectively reduced by 3 magnitudes (from 0.1 mA to 20 nA) and was increased to 1.2 × 10 Jones by introducing PC71BM. The TiO/PC71BM heterojunction also made the PD self-powered, and by further introducing an interface layer of PEDOT:PSS and finely optimizing the electrode Ag nanowires (Ag NWs), the self-powered responsivity () was increased to 33 mA/W. Ultrafast rise/decay times (129 ns/1 ms at -1 V and 0.06 s/<1 μs at 0 V) were achieved. This work successfully applied an organic-inorganic heterojunction, an organic interface, and Ag NWs to suppress the dark current and enhance the self-powered photocurrent/ of inorganic PDs, providing a feasible strategy in high-performance UV PDs' design.
近年来，基于TiO的光电探测器（PDs）因其出色的热稳定性和在紫外（UV）光下的光电性能而成为研究热点。然而，TiO薄膜中的缺陷导致的高暗电流限制了这些PDs的探测率（）。在此，通过引入PC71BM，基于TiO的PD的暗电流有效降低了3个数量级（从0.1 mA降至20 nA），探测率提高到1.2×10琼斯。TiO/PC71BM异质结还使PD实现了自供电，通过进一步引入PEDOT:PSS界面层并精细优化电极银纳米线（Ag NWs），自供电响应度（）提高到33 mA/W。实现了超快的上升/下降时间（在-1 V时为129 ns/1 ms，在0 V时为0.06 s/<1 μs）。这项工作成功地应用了有机-无机异质结、有机界面和Ag NWs来抑制暗电流并增强无机PDs的自供电光电流/，为高性能紫外PDs的设计提供了一种可行的策略。
