Multilayer SnS2/few-layer MoS2 heterojunctions with in-situ floating photogate toward high-performance photodetectors and optical imaging application

• Published in: Science China materials Vol. 66; no. 5; pp. 1879 - 1890
• Main Authors: Yi, Huaxin, Yang, Hailin, Ma, Churong, Ma, Yuhang, Ye, Qiaojue, Lu, Jianting, Wang, Wan, Zheng, Zhaoqiang, Deng, Zexiang, Zou, Yichao, Yao, Jiandong, Yang, Guowei
• Format: Journal Article
• Language: English
• Published: Beijing Science China Press 01.05.2023; Springer Nature B.V
• Subjects: Carrier lifetime; Chemical vapor deposition; Chemistry and Materials Science; Chemistry/Food Science; Dark current; Heterojunctions; Heterostructures; Holes (electron deficiencies); Layered materials; Materials Science; Molybdenum disulfide; Multilayers; Optoelectronic devices; Photometers; Photosensitivity; Recovery time; Response rates; Tin disulfide; photodetectors; 2D layered materials; van der Waals heterojunctions; optical imaging; floating photogate
• ISSN: 2095-8226; 2199-4501
• DOI: 10.1007/s40843-022-2338-9

Since the successful preparation of the monolayer MoS 2 phototransistor, two-dimensional (2D) layered materials (2DLMs) have been regarded as one of the most compelling candidates toward the implementation of the next generation of novel optoelectronic devices and systems. However, most reported 2DLM photodetectors suffer from specific shortcomings, such as low responsivity, large dark current, low specific detectivity, low on/off ratio, and sluggish response rate. Herein, multilayer SnS 2 /few-layer MoS 2 van der Waals heterostructures have been constructed by stacking the MoS 2 and SnS 2 nanosheets grown by a single atmospheric pressure chemical vapor deposition method. The SnS 2 /MoS 2 heterojunction photodetector demonstrates competitive overall performance with a large on/off ratio of 171, a high responsivity of 28.3 A W −1 , and an excellent detectivity of 1.2 × 10 13 Jones. In addition, an ultrafast response rate with the response/recovery time down to 1.38 ms/600 µs is achieved. The excellent properties are associated with the synergy of type-II band alignment of SnS 2 /MoS 2 and the in-situ formed seamless floating photogate, which contribute to separating the photoexcited electron-hole pairs and extending the carrier lifetime. Taking advantage of the excellent photosensitivity, the SnS 2 /MoS 2 device demonstrates proof-of-concept optical imaging application. On the whole, this study provides a distinctive perspective to implement advanced photodetectors with competitive overall performance.