Two-Dimensional Pyramid-like WS<sub>2</sub> Layered Structures for Highly Efficient Edge Second-Harmonic Generation Xianqing Lin Yingying Liu Kang Wang Cong Wei Wei Zhang Yongli Yan Yong Jun Li Jiannian Yao Yong Sheng Zhao 10.1021/acsnano.7b07823.s001 https://acs.figshare.com/articles/journal_contribution/Two-Dimensional_Pyramid-like_WS_sub_2_sub_Layered_Structures_for_Highly_Efficient_Edge_Second-Harmonic_Generation/5760810 Two-dimensional (2D) layered materials, with large second-order nonlinear susceptibility, have received much scientific interest due to their potential applications in nonlinear optical devices. However, the atomic thickness of 2D layered materials leads to poor field confinement and weak light–matter interaction at the nanoscale, resulting in low nonlinear conversion efficiency. Here, 2D pyramid-like multilayer (P-multilayer) layered structures are fabricated for efficient edge second-harmonic generation (SHG) based on the enhanced light–matter interaction in whispering-gallery mode (WGM) cavities. The P-multilayer 2D layered materials, where the basal planes shrink gradually from the bottom to the top layers, exhibit efficient edge SH radiation due to the partial destructive interference of nonlinear polarizations between the neighboring atomic layers. Moreover, the well-defined 2D plate-like triangle morphology of P-multilayer WS<sub>2</sub> forms a WGM resonance cavity, which results in enhanced light–matter interaction and thus the enhancement of edge SHG, which can be further enhanced by hybridizing the WGM mode with plasmonics. These results provide enlightenment for the construction of specific structures for efficient nonlinear processes. 2018-01-02 00:00:00 P-multilayer 2 D nonlinear conversion efficiency WGM mode edge second-harmonic generation basal planes edge SHG nonlinear polarizations edge SH radiation 2 D pyramid-like nonlinear susceptibility whispering-gallery mode P-multilayer WS 2 forms material WGM resonance cavity nonlinear processes Two-Dimensional Pyramid-like WS 2 Layered Structures 2 D interaction field confinement 2 D plate-like triangle morphology