title: Facile fabrication of wafer-scale MoS2 neat films with enhanced third-order nonlinear optical performance.
abstract: Wafer-scale MoS2 neat films with controllable thicknesses were successfully fabricated by vacuum filtering liquid-exfoliated MoS2 dispersions. The obtained MoS2 filtered thin films were systematically characterized by UV-Vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, atomic force microscopy (AFM) and scanning electron microscopy (SEM). It was found that the fabricated scalable MoS2 films have a smooth surface and high optical homogeneity verified by AFM and a collimated 532 nm beam, respectively. We investigated the ultrafast nonlinear optical (NLO) properties of the filtered films by an open aperture Z-scan method using 515 and 1030 nm femtosecond laser pulses. Saturable absorption was observed at both 515 and 1030 nm with the figure of merit (FOM) values as ∼3.3 × 10(-12) esu cm and ∼3.4 × 10(-14) esu cm, respectively. The observation of ultrafast NLO performance of the MoS2 filtered films indicates that vacuum filtration is a feasible method for the fabrication of optical thin films, which can be expanded to fabricate other two-dimensional films from the corresponding dispersions. This easy film fabrication technology will greatly enlarge the application of graphene analogues including graphene in photonic devices, especially of MoS2 as a saturable absorber.
authors.affiliation: Key Laboratory of Materials for High-Power Laser, Shanghai Institute of Optics and Fine Mechanics (SIOM), Chinese Academy of Sciences (CAS), Shanghai 201800, China. jwang@siom.ac.cn.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Zhang
authors.forename: Saifeng
authors.initials: S
authors.lastname: Zhang
authors.forename: Chunxia
authors.initials: C
authors.lastname: Chang
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Feng
authors.forename: Yuanxin
authors.initials: Y
authors.lastname: Li
authors.forename: Ningning
authors.initials: N
authors.lastname: Dong
authors.forename: Kangpeng
authors.initials: K
authors.lastname: Wang
authors.forename: Long
authors.initials: L
authors.lastname: Zhang
authors.forename: Werner J
authors.initials: WJ
authors.lastname: Blau
authors.forename: Jun
authors.initials: J
authors.lastname: Wang