中国物理B ›› 2025, Vol. 34 ›› Issue (8): 84206-084206.doi: 10.1088/1674-1056/addaa3

所属专题: SPECIAL TOPIC — Artificial intelligence and smart materials innovation: From fundamentals to applications

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Strain modulation of second harmonic generation in new tetrahedral transition metal dichalcogenide monolayers

Hu Chen(陈虎)1,3, Shi-Qi Li(李仕琪)1,3,†, Yuqing Wu(吴雨晴)1,3, Xiaozhendong Bao(鲍晓振东)1,3, Zhijie Lei(雷志杰)1,3, Hongsheng Liu(柳洪盛)2, Yuee Xie(谢月娥)1,3,‡, Junfeng Gao(高峻峰)2,§, Yuanping Chen(陈元平)1,3, and Xiaohong Yan(颜晓红)1,3   

  1. 1 School of Physics and Electronic Engineering, Jiangsu University, Zhenjiang 212013, China;
    2 Laboratory of Materials Modification by Laser, Ion and Electron Beams, Ministry of Education, Dalian University of Technology, Dalian 116024, China;
    3 Quantum Sensing and Agricultural Intelligence Detection Engineering Center of Jiangsu Province, Zhenjiang 212013, China
  • 收稿日期:2025-03-26 修回日期:2025-05-16 接受日期:2025-05-20 出版日期:2025-07-17 发布日期:2025-08-08
  • 通讯作者: Shi-Qi Li, Yuee Xie, Junfeng Gao E-mail:shiqili@ujs.edu.cn;yueex@ujs.edu.cn;gaojf@dlut.edu.cn
  • 基金资助:
    This work is supported by the National Natural Science Foundation of China (Grant Nos. 12304220, 12174157, 12074150, and 12374174), the Natural Science Foundation of Jiangsu Province (Grant No. BK20230518), the China Postdoctoral Science Foundation (Grant No. 2023M731383), the College Student Innovation Project (Grant No. 202410299946X), and the Scientific Research Project of Jiangsu University (Grant No. 22A397).

Strain modulation of second harmonic generation in new tetrahedral transition metal dichalcogenide monolayers

Hu Chen(陈虎)1,3, Shi-Qi Li(李仕琪)1,3,†, Yuqing Wu(吴雨晴)1,3, Xiaozhendong Bao(鲍晓振东)1,3, Zhijie Lei(雷志杰)1,3, Hongsheng Liu(柳洪盛)2, Yuee Xie(谢月娥)1,3,‡, Junfeng Gao(高峻峰)2,§, Yuanping Chen(陈元平)1,3, and Xiaohong Yan(颜晓红)1,3   

  1. 1 School of Physics and Electronic Engineering, Jiangsu University, Zhenjiang 212013, China;
    2 Laboratory of Materials Modification by Laser, Ion and Electron Beams, Ministry of Education, Dalian University of Technology, Dalian 116024, China;
    3 Quantum Sensing and Agricultural Intelligence Detection Engineering Center of Jiangsu Province, Zhenjiang 212013, China
  • Received:2025-03-26 Revised:2025-05-16 Accepted:2025-05-20 Online:2025-07-17 Published:2025-08-08
  • Contact: Shi-Qi Li, Yuee Xie, Junfeng Gao E-mail:shiqili@ujs.edu.cn;yueex@ujs.edu.cn;gaojf@dlut.edu.cn
  • Supported by:
    This work is supported by the National Natural Science Foundation of China (Grant Nos. 12304220, 12174157, 12074150, and 12374174), the Natural Science Foundation of Jiangsu Province (Grant No. BK20230518), the China Postdoctoral Science Foundation (Grant No. 2023M731383), the College Student Innovation Project (Grant No. 202410299946X), and the Scientific Research Project of Jiangsu University (Grant No. 22A397).

摘要: Designing novel two-dimensional structures and precisely modulating their second harmonic generation (SHG) attributes are key to advancing nonlinear photonic technologies. In this work, through first-principles calculations, we propose a novel tetrahedral phase of transition metal dichalcogenides (TMDs) and validate its structural feasibility in a family of compounds, i.e., $ZX_2$ ($Z = {\rm Ti}$, Zr, Hf; $X ={\rm S}$, Se, Te). Cohesive energy and phonon dispersion calculations further demonstrate that eight of nine possible $ZX_2$ monolayers are dynamically stable. All the $ZX_2$ monolayers exhibit pronounced out-of-plane SHG with nonlinear susceptibility components reaching the order of 10$^2$ pm/V. Strain engineering imposes a profound influence on the SHG response of $ZX_2$ monolayers by reducing symmetry and modifying nonlinear susceptibility components. The redshift and significant enhancement of the prominent peak in SHG spectra are also revealed due to strain-induced charge redistribution and band gap reduction. Intriguingly, strain-driven nonlinear optical switching effects are realized in the $ZX_2$ monolayers, with a reversible switching of SHG component ordering under tensile and compressive strain. In such a case, the anisotropic SHG pattern transforms from fourfold to twofold symmetry under the strain. Our work demonstrates the efficacy of strain engineering in precisely enhancing SHG, paving the way for the integration of novel TMD structures into tunable and flexible nonlinear optical devices.

关键词: second harmonic generation, strain modulation, transition metal dichalcogenides, phase

Abstract: Designing novel two-dimensional structures and precisely modulating their second harmonic generation (SHG) attributes are key to advancing nonlinear photonic technologies. In this work, through first-principles calculations, we propose a novel tetrahedral phase of transition metal dichalcogenides (TMDs) and validate its structural feasibility in a family of compounds, i.e., $ZX_2$ ($Z = {\rm Ti}$, Zr, Hf; $X ={\rm S}$, Se, Te). Cohesive energy and phonon dispersion calculations further demonstrate that eight of nine possible $ZX_2$ monolayers are dynamically stable. All the $ZX_2$ monolayers exhibit pronounced out-of-plane SHG with nonlinear susceptibility components reaching the order of 10$^2$ pm/V. Strain engineering imposes a profound influence on the SHG response of $ZX_2$ monolayers by reducing symmetry and modifying nonlinear susceptibility components. The redshift and significant enhancement of the prominent peak in SHG spectra are also revealed due to strain-induced charge redistribution and band gap reduction. Intriguingly, strain-driven nonlinear optical switching effects are realized in the $ZX_2$ monolayers, with a reversible switching of SHG component ordering under tensile and compressive strain. In such a case, the anisotropic SHG pattern transforms from fourfold to twofold symmetry under the strain. Our work demonstrates the efficacy of strain engineering in precisely enhancing SHG, paving the way for the integration of novel TMD structures into tunable and flexible nonlinear optical devices.

Key words: second harmonic generation, strain modulation, transition metal dichalcogenides, phase

中图分类号:  (Nonlinear optics)

  • 42.65.-k
42.65.An (Optical susceptibility, hyperpolarizability) 73.22.-f (Electronic structure of nanoscale materials and related systems) 42.65.Ky (Frequency conversion; harmonic generation, including higher-order harmonic generation)