Enhanced second-harmonic generation in monolayer MoS2 on suspended metallic nanostructures by plasmonic resonances
Leng Qing,
Su Huanhuan,
Liu Jianqiang,
Zhou Lin,
Qin Kang,
Wang Qianjin,
Fu Junqi,
Wu Shan,
Zhang Xuejin
Affiliations
Leng Qing
Key Laboratory of Functional Materials and Devices for Informatics of Anhui Higher Education Institutes, Fuyang Normal University, Fuyang, 236037, China
Su Huanhuan
National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, School of Physics and College of Engineering and Applied Sciences, Nanjing University, Nanjing210093, China
Liu Jianqiang
School of Science, Jiujiang University, Jiujiang332005, China
Zhou Lin
National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, School of Physics and College of Engineering and Applied Sciences, Nanjing University, Nanjing210093, China
Qin Kang
National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, School of Physics and College of Engineering and Applied Sciences, Nanjing University, Nanjing210093, China
Wang Qianjin
National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, School of Physics and College of Engineering and Applied Sciences, Nanjing University, Nanjing210093, China
Fu Junqi
Key Laboratory of Functional Materials and Devices for Informatics of Anhui Higher Education Institutes, Fuyang Normal University, Fuyang, 236037, China
Wu Shan
Key Laboratory of Functional Materials and Devices for Informatics of Anhui Higher Education Institutes, Fuyang Normal University, Fuyang, 236037, China
Zhang Xuejin
National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, School of Physics and College of Engineering and Applied Sciences, Nanjing University, Nanjing210093, China
Monolayer transition metal dichalcogenides (TMDs) possess large second-order nonlinear responses due to the broken inversion symmetry, which can extend their intriguing applications in nonlinear nanophotonics and optoelectronics. However, the atomic thickness of monolayer TMDs severely decreases the interaction length with free light with respect to bulk materials, leading to rather low second-harmonic generation (SHG) conversion efficiency. Here, we demonstrate a hybrid structure consisting of a monolayer MoS2 on a suspended perforated silver film, on which the SHG signal emitted from the monolayer MoS2 is enhanced by more than three orders of magnitude at room temperature. The pronounced SHG enhancement is attributed to the distinct electric field amplification nearby the nanoholes, which is induced by the symmetric surface plasmon polaritons (SPPs) existing in the ultrathin suspended silver grating. Our results reported here may establish the substrate-free engineering of nonlinear optical effects via plasmonic nanostructures on demand.
