He Zhigang, Guan Heyuan, Liang Xijie, Chen Junteng, Xie Manyan, Luo Kaiwen, An Ran, Ma Liang, Ma Fengkai, Yang Tiefeng, Lu Huihui
Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Jinan University, Guangzhou 510632, China.
Key Laboratory of Optoelectronic Information and Sensing Technologies of Guangdong Higher Education Institutes, Jinan University, Guangzhou 510632, China.
Research (Wash D C). 2023 Jul 20;6:0199. doi: 10.34133/research.0199. eCollection 2023.
High-performance photodetectors hold promising potential in optical communication and imaging systems. However, conventional counterparts are suffering narrow detection range, high power consumption, and poor polarization sensitivity. Characteristics originating from switchable polarization in ferroelectrics can be used to optimize the photo-to-electric procedure and improve the photodetection performance. In this regard, we constructed a configuration by integrating 2-dimensional molybdenum disulfide (MoS) with ferroelectric lithium niobate (LiNbO), resulting in the MoS/LiNbO heterostructured photodetector. Benefiting from the pyroelectric effect of LiNbO, the limitation of bandgap on the detection range can be broken, thus broadening the response band of the detector to 365 to 1,064 nm, as well as enabling the self-powered characteristic. Meanwhile, high carrier mobility and decent light absorbance of MoS introduce robust light-matter interactions with the underlying LiNbO, leading to ultrafast rise/fall times of ≈150 μs/250 μs and switching ratios of up to ≈190. Moreover, the highest responsivity, specific detectivity, and external quantum efficiency achieved were 17.3 A·W, 4.3 × 10 Jones, and 4,645.78%, respectively. Furthermore, because of the anisotropy of the spontaneous-polarized LiNbO substrate, the photocurrent of the device achieved a dichroic ratio of 7.42, comparing favorably to most MoS-based photodetectors. This work demonstrates the integration potential between ferroelectric LiNbO and 2-dimensional materials for high-performance photodetection.
高性能光电探测器在光通信和成像系统中具有广阔的应用前景。然而，传统的光电探测器存在检测范围窄、功耗高和偏振灵敏度差等问题。铁电体中可切换偏振特性可用于优化光电转换过程并提高光电探测性能。在此方面，我们通过将二维二硫化钼（MoS）与铁电铌酸锂（LiNbO）集成构建了一种结构，得到了MoS/LiNbO异质结构光电探测器。受益于LiNbO的热释电效应，可突破带隙对检测范围的限制，从而将探测器的响应波段拓宽至365至1064 nm，同时实现自供电特性。此外，MoS的高载流子迁移率和良好的光吸收特性与下层的LiNbO产生了强烈的光-物质相互作用，使得上升/下降时间超快，约为150 μs/250 μs，开关比高达约190。此外，实现的最高响应度、比探测率和外量子效率分别为17.3 A·W、4.3×10琼斯和4645.78%。此外，由于自发极化的LiNbO衬底具有各向异性，该器件的光电流实现了7.42的二向色比，优于大多数基于MoS的光电探测器。这项工作展示了铁电LiNbO与二维材料在高性能光电探测方面的集成潜力。
