MIIT Key Laboratory of Advanced Display Materials and Devices, Institute of Optoelectronics & Nanomaterials, College of Materials Science and Engineering, Nanjing University of Science and Technology , Nanjing 210094, China.
State Key Laboratory of Mechanics and Control of Mechanical Structures, College of Materials science and Technology, Nanjing University of Aeronautics and Astronautics , Nanjing 210016, China.
ACS Nano. 2017 Feb 28;11(2):2015-2023. doi: 10.1021/acsnano.6b08194. Epub 2017 Jan 24.
Intrinsically high mobility and large absorption coefficient endow inorganic halide perovskites (IHPs) with great promise for high-performance photodetectors (PDs), which, however, are being hindered by the low carrier extraction and transport efficiency of the solution assembled films. Here, we report on a general strategy to enhance the perovskite film conductivity that carbon nanotubes (CNTs) conductive nanonets are constructed from to provide fast carrier tracks. Resultantly, the CsPbBr nanosheet/CNT composite films exhibit both high light harvesting and high conductivity, such advantages are demonstrated by the high performances of corresponding planar PDs. Specifically, the highest external quantum efficiency (EQE) of 7488% and the highest responsivity of 31.1 A W under a bias of 10 V among IHP PDs with planar structure are achieved, which are almost 125-fold over the previous best results. Besides, the efficient charge extraction and transport also remarkably contribute to the fast response speed where a rise time of 16 μs is achieved, which is also superior to state-of-the-art IHP PDs. Furthermore, the composite films exhibit impressive flexibility due to the ultrathin 2D and 1D structural characteristic of perovskites and CNTs. By deploying the PD as a point-like detector, we acquire clear images. The results indicate the promising potentials of the perovskite/CNT composites for solution and ambient condition processed flexible devices, and this strategy is general for all kinds of perovskite optoelectronic devices including photodetectors, phototransistors, and even LEDs.
本征迁移率高和大吸收系数使无机卤化物钙钛矿（IHPs）在高性能光电探测器（PDs）方面具有巨大的应用前景，但溶液组装薄膜的载流子提取和输运效率低阻碍了其发展。在这里，我们报告了一种增强钙钛矿薄膜导电性的通用策略，即用碳纳米管（CNTs）构建导电纳米网，为载流子提供快速传输通道。结果，CsPbBr 纳米片/CNT 复合薄膜具有高光捕获和高导电性，这一优势体现在相应平面 PD 的高性能上。具体来说，在 10 V 偏压下，具有平面结构的 IHP PD 的最高外量子效率（EQE）为 7488%，最高响应率为 31.1 A W，这几乎是之前最佳结果的 125 倍。此外，高效的电荷提取和输运也显著促进了快速响应速度，上升时间为 16 μs，优于最先进的 IHP PD。此外，由于钙钛矿和 CNT 的超薄 2D 和 1D 结构特性，复合薄膜具有出色的柔韧性。通过将 PD 用作点状探测器，我们获得了清晰的图像。结果表明，钙钛矿/CNT 复合材料在溶液和环境条件下处理的柔性器件中具有很大的应用潜力，该策略适用于各种钙钛矿光电探测器，包括光电晶体管，甚至是 LED。
