Li Jitao, Bai Jing, Meng Ming, Hu Chunhong, Yuan Honglei, Zhang Yan, Sun Lingling
School of Physics and Telecommunications Engineering, Zhoukou Normal University, Zhoukou 466001, China.
The Key Laboratory of Rare Earth Functional Materials of Henan Province, Zhoukou Normal University, Zhoukou 466001, China.
Nanomaterials (Basel). 2022 Apr 15;12(8):1365. doi: 10.3390/nano12081365.
Temporal response is an important factor limiting the performance of two-dimensional (2D) material photodetectors. The deep trap states caused by intrinsic defects are the main factor to prolong the response time. In this work, it is demonstrated that the trap states in 2D molybdenum disulfide (MoS) can be efficiently modulated by defect engineering through mild oxygen plasma treatment. The response time of the few-layer MoS photodetector is accelerated by 2-3 orders of magnitude, which is mainly attributed to the deep trap states that can be easily filled when O or oxygen ions are chemically bonded with MoS at sulfur vacancies (SV) sites. We characterized the defect engineering of plasma-exposed MoS by Raman, PL and electric properties. Under the optimal processing conditions of 30 W, 50 Pa and 30 s, we found 30-fold enhancements in photoluminescence (PL) intensity and a nearly 2-fold enhancement in carrier field-effect mobility, while the rise and fall response times reached 110 ms and 55 ms, respectively, at the illumination wavelength of 532 nm. This work would, therefore, offer a practical route to improve the performance of 2D dichalcogenide-based devices for future consideration in optoelectronics research.
时间响应是限制二维（2D）材料光电探测器性能的一个重要因素。由本征缺陷引起的深陷阱态是延长响应时间的主要因素。在这项工作中，证明了通过温和的氧等离子体处理进行缺陷工程可以有效地调制二维二硫化钼（MoS）中的陷阱态。几层MoS光电探测器的响应时间加快了2 - 3个数量级，这主要归因于当O或氧离子在硫空位（SV）位点与MoS化学键合时，深陷阱态能够容易地被填充。我们通过拉曼光谱、光致发光（PL）和电学性质对经等离子体处理的MoS的缺陷工程进行了表征。在30 W、50 Pa和30 s的最佳处理条件下，我们发现光致发光（PL）强度提高了30倍，载流子场效应迁移率提高了近2倍，而在532 nm的照明波长下，上升和下降响应时间分别达到了110 ms和55 ms。因此，这项工作将为提高基于二维二硫属化物的器件性能提供一条切实可行的途径，以供未来在光电子学研究中参考。
