Poly(4-styrenesulfonate)-induced sulfur vacancy self-healing strategy for monolayer MoS2 homojunction photodiode

• Published in: Nature communications Vol. 8; no. 1; pp. 15881 - 8
• Main Authors: Zhang, Xiankun, Liao, Qingliang, Liu, Shuo, Kang, Zhuo, Zhang, Zheng, Du, Junli, Li, Feng, Zhang, Shuhao, Xiao, Jiankun, Liu, Baishan, Ou, Yang, Liu, Xiaozhi, Gu, Lin, Zhang, Yue
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 22.06.2017; Nature Publishing Group; Nature Portfolio
• Subjects: 140/133; 140/146; 142/136; 639/301/1005/1007; 639/301/357/1018; 639/301/357/551; 639/638/298/917; Adatoms; Clusters; Electron states; Healing; Homojunctions; Humanities and Social Sciences; Hydrogenation; Lattice vacancies; Molybdenum disulfide; multidisciplinary; Optoelectronics; Science; Science (multidisciplinary); Strategy; Sulfur
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms15881

We establish a powerful poly(4-styrenesulfonate) (PSS)-treated strategy for sulfur vacancy healing in monolayer MoS 2 to precisely and steadily tune its electronic state. The self-healing mechanism, in which the sulfur vacancies are healed spontaneously by the sulfur adatom clusters on the MoS 2 surface through a PSS-induced hydrogenation process, is proposed and demonstrated systematically. The electron concentration of the self-healed MoS 2 dramatically decreased by 643 times, leading to a work function enhancement of ∼150 meV. This strategy is employed to fabricate a high performance lateral monolayer MoS 2 homojunction which presents a perfect rectifying behaviour, excellent photoresponsivity of ∼308 mA W −1 and outstanding air-stability after two months. Unlike previous chemical doping, the lattice defect-induced local fields are eliminated during the process of the sulfur vacancy self-healing to largely improve the homojunction performance. Our findings demonstrate a promising and facile strategy in 2D material electronic state modulation for the development of next-generation electronics and optoelectronics. Two-dimensional MoS 2 homojunctions, considered potential building blocks for next generation flexible electronics, currently suffer from quick degradation. Here, Zhang and co-workers use a self-healing sulfur vacancy mechanism to produce a MoS 2 photodiode that possesses long term stability.