Liu Xinxin, Li Feng, Xu Minxuan, Qi Junjie
State Key Laboratory for Advanced Metals and Materials, School of Materials Science and Engineering, University of Science and Technology Beijing Beijing 100083 People's Republic of China
RSC Adv. 2018 Aug 6;8(49):28041-28047. doi: 10.1039/c8ra05511d. eCollection 2018 Aug 2.
Here, we firstly fabricated a metal-insulator-semiconductor (MIS) (Pd/AlO/MoS) self-powered photodetector based on MoS, which is sensitive to the illumination of light without any external bias, exhibiting a high responsivity of 308 mA W. Under bias, it shows a ratio of photocurrent to dark current exceeding 3705, a high photoresponsivity of 5.04 A W, and a fast response/recovery time of 468 ms/543 ms. The optoelectronic performances of the photodetector are closely related to the insulating layer, which can suppress the dark current of the photodetectors, and prevent strong current drifting and degradation by environmental effects, playing a key role in carrier tunneling. Furthermore, we used a thin HfO film as the insulating layer to improve the optoelectronics performance of the MIS structured self-powered photodetector, which presented a high responsivity of 538 mA W at 0 bias. With an applied bias, it exhibits an on/off ratio up to 6653, a photoresponsivity of 25.46 A W, and a response/recovery time of 7.53 ms/159 ms. Our results lead to a new way for future application of high performance MIS structured photodetectors based on 2D MoS.
在此，我们首先基于二硫化钼（MoS₂）制备了一种金属-绝缘体-半导体（MIS）（Pd/Al₂O₃/MoS₂）自供电光电探测器，该探测器在无任何外部偏压的情况下对光照敏感，展现出308 mA/W的高响应度。在施加偏压时，其光电流与暗电流之比超过3705，光响应度高达5.04 A/W，响应/恢复时间分别为468 ms/543 ms。该光电探测器的光电性能与绝缘层密切相关，绝缘层可抑制光电探测器的暗电流，并防止因环境影响导致的强电流漂移和性能退化，在载流子隧穿中起关键作用。此外，我们使用氧化铪（HfO₂）薄膜作为绝缘层来改善MIS结构自供电光电探测器的光电性能，该探测器在0偏压下呈现出538 mA/W的高响应度。施加偏压时，其开/关比高达6653，光响应度为25.46 A/W，响应/恢复时间分别为7.53 ms/159 ms。我们的研究结果为基于二维MoS₂的高性能MIS结构光电探测器的未来应用开辟了一条新途径。
