Tao Lili, Long Hui, Zhou Bo, Yu Siu Fung, Lau Shu Ping, Chai Yang, Fung Kin Hung, Tsang Yuen Hong, Yao Jianquan, Xu Degang
Department of Applied Physics and Materials Research Center, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
Nanoscale. 2014 Aug 21;6(16):9713-9. doi: 10.1039/c4nr02664k.
Due to the relatively weak van der Waals (VDW) force between interlayers, few-layer MoS2 nanosheets are prepared using a simple ultrasonic exfoliation method and incorporated into PMMA. The good nonlinear optical (NLO) property of the MoS2/PMMA composite for the nanosecond pulsed laser at both 532 and 1064 nm has been first reported. The size, thickness and atomic structure of MoS2 nanosheets have been characterized by transmission electron microscopy (TEM) and atomic force microscopy (AFM). The interesting dependence of interlayer separation with respect to the layer number of MoS2 has been successfully quantified. The average interlayer separation of the MoS2 nanosheets increases and deviates much from the theoretical value with reducing the layer number. Such few-layer MoS2 nanosheets have been homogeneously incorporated into solid-state PMMA, which shows low optical limiting thresholds, 0.4 and 1.3 J cm(-2), and low limiting differential transmittance (TC), 2% and 3% for the nanosecond laser operating at 532 nm and 1064 nm, respectively. The results suggest that MoS2 nanosheet incorporated PMMA is a promising candidate of the solid NLO material for optical limiting applications.
由于层间的范德华力相对较弱，采用简单的超声剥离法制备了少层MoS₂纳米片并将其掺入聚甲基丙烯酸甲酯（PMMA）中。首次报道了MoS₂/PMMA复合材料在532和1064 nm的纳秒脉冲激光下具有良好的非线性光学（NLO）特性。通过透射电子显微镜（TEM）和原子力显微镜（AFM）对MoS₂纳米片的尺寸、厚度和原子结构进行了表征。成功量化了MoS₂层间距与层数之间有趣的依赖关系。随着层数减少，MoS₂纳米片的平均层间距增大且与理论值偏差较大。这种少层MoS₂纳米片已均匀地掺入固态PMMA中，对于在532 nm和1064 nm工作的纳秒激光，其光学限幅阈值分别为0.4和1.3 J cm⁻²，限幅微分透过率（TC）分别为2%和3%，均较低。结果表明，掺入MoS₂纳米片的PMMA是用于光学限幅应用的固态NLO材料的有前途的候选者。
