title: Highly sensitive and fast monolayer WS2phototransistors realized by SnS nanosheet decoration.
abstract: Two-dimensional chalcogenide monolayers are strong candidates for next-generation flexible and transparent optoelectronics. Due to the intrinsic ultrathin thickness and limited optical absorption, however, their responsivity is normally low. Here we develop a simple and low-cost method to fabricate high-performance hybrid phototransistors of monolayer WS2with significantly enhanced responsivity and an extended spectral response range, by virtue of surface decoration with liquid-phase exfoliated SnS nanosheets (NSs). The hybrid phototransistors show a much enhanced responsivity of ∼2 A W-1and an ultrahigh light/dark signal-to-noise ratio of 106under 457 nm excitation, exhibiting a significant increase of 3 orders of magnitude in responsivity and a 100 fold increase in signal-to-noise ratio, compared with pure WS2devices. Our hybrid photodetectors also exhibit a respectable response speed, with a rise and decay time of 51 μs and 98 μs, respectively. After optimal surface decoration with narrow bandgap SnS NSs atop a monolayer WS2channel, an emergent optical responsivity in the near infrared region (1064 nm) is also observed.
authors.affiliation: State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinghuangdao 066004, China. jyxiang@ysu.edu.cn wenfsh@ysu.edu.cn liuzy0319@ysu.edu.cn.
authors.forename: Zhiyan
authors.initials: Z
authors.lastname: Jia
authors.affiliation: School of Electronic Science and Engineering, Nanjing University, Nanjing 210093, China.
authors.forename: Songlin
authors.initials: S
authors.lastname: Li
authors.affiliation: State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinghuangdao 066004, China. jyxiang@ysu.edu.cn wenfsh@ysu.edu.cn liuzy0319@ysu.edu.cn.
authors.forename: Jianyong
authors.identifier: http://orcid.org/0000-0001-9374-7127
authors.initials: J
authors.lastname: Xiang
authors.affiliation: State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinghuangdao 066004, China. jyxiang@ysu.edu.cn wenfsh@ysu.edu.cn liuzy0319@ysu.edu.cn.
authors.forename: Fusheng
authors.initials: F
authors.lastname: Wen
authors.affiliation: State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinghuangdao 066004, China. jyxiang@ysu.edu.cn wenfsh@ysu.edu.cn liuzy0319@ysu.edu.cn.
authors.forename: Xuan
authors.initials: X
authors.lastname: Bao
authors.affiliation: State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinghuangdao 066004, China. jyxiang@ysu.edu.cn wenfsh@ysu.edu.cn liuzy0319@ysu.edu.cn.
authors.forename: Shanghuai
authors.initials: S
authors.lastname: Feng
authors.affiliation: State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinghuangdao 066004, China. jyxiang@ysu.edu.cn wenfsh@ysu.edu.cn liuzy0319@ysu.edu.cn.
authors.forename: Ruilong
authors.initials: R
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinghuangdao 066004, China. jyxiang@ysu.edu.cn wenfsh@ysu.edu.cn liuzy0319@ysu.edu.cn.
authors.forename: Zhongyuan
authors.initials: Z
authors.lastname: Liu