Zhou Yuchen, Zhang Li, Gao Wei, Yang Mengmeng, Lu Jianting, Zheng Zhaoqiang, Zhao Yu, Yao Jiandong, Li Jingbo
School of Materials and Energy, Guangdong University of Technology, Guangzhou, 510006, Guangdong, P. R. China.
Nanoscale. 2021 Mar 21;13(11):5660-5669. doi: 10.1039/d1nr00210d. Epub 2021 Mar 16.
Heterojunctions based on low-dimensional materials can combine the superiorities of each component and realize novel properties. Herein, a mixed-dimensional heterojunction comprising multilayer WS, CdS microwire, and few-layer WS has been demonstrated. The working mechanism and its application in a photodetector are investigated. The multilayer WS and CdS microwire are utilized to provide efficient light absorption, while the few-layer WS is utilized to passivate interfacial impurity scattering. In addition, based on the reasonable band alignment of the components, three built-in electric fields are formed, which efficiently separate the photo-generated carriers and enhance the photocurrent. In particular, the photo-generated electrons are trapped in CdS, while the photo-generated holes circulate in the external circuit, leading to a high photoconductivity gain. Motivated by these, we constructed a device that exhibits a photoresponsivity of ∼4.7 A W, a response/recovery time of 13.7/15.8 ms, and a detectivity of 3.4 × 10 Jones, which are much better than the counterparts. All of these clearly demonstrate the importance of advanced device designs for realizing high performance optoelectronic devices.
基于低维材料的异质结可以结合各组分的优势并实现新颖的性能。在此，已展示了一种由多层WS、CdS微线和少层WS组成的混合维度异质结。研究了其工作机制及其在光电探测器中的应用。多层WS和CdS微线用于提供高效的光吸收，而少层WS用于钝化界面杂质散射。此外，基于各组分合理的能带排列，形成了三个内建电场，有效地分离了光生载流子并增强了光电流。特别地，光生电子被困在CdS中，而光生空穴在外部电路中循环，导致高光导增益。受此启发，我们构建了一种器件，其表现出约4.7 A W的光响应度、13.7/15.8 ms的响应/恢复时间以及3.4×10琼斯的探测率，这些都远优于同类器件。所有这些都清楚地证明了先进器件设计对于实现高性能光电器件的重要性。
