Modulation of the second-harmonic generation in MoS2 by graphene coveringProject supported by Beijing Natural Science Foundation, China (Grant No. JQ19004), Beijing Excellent Talents Training Support, China (Grant No. 2017000026833ZK11), the National Natural Science Foundation of China (Grant Nos. 52025023, 51991340, and 51991342), the National Key Research and Development Program of China (Grant Nos. 2016YFA0300903 and 2016YFA0300804), the Key R&D Program of Guangdong Province, China (Grant Nos

• Published in: Chinese physics B Vol. 30; no. 2
• Main Authors: Wu, Chunchun, Shang, Nianze, Zhao, Zixun, Zhang, Zhihong, Liang, Jing, Liu, Chang, Zuo, Yonggang, Ding, Mingchao, Wang, Jinhuan, Hong, Hao, Xiong, Jie, Liu, Kaihui
• Format: Journal Article
• Language: English
• Published: Chinese Physical Society and IOP Publishing Ltd 01.02.2021
• Subjects: dielectric screening; graphene; second harmonic generation (SHG); two-dimensional materials
• ISSN: 1674-1056
• DOI: 10.1088/1674-1056/abd77f

Nonlinear optical frequency mixing, which describes new frequencies generation by exciting nonlinear materials with intense light field, has drawn vast interests in the field of photonic devices, material characterization, and optical imaging. Investigating and manipulating the nonlinear optical response of target materials lead us to reveal hidden physics and develop applications in optical devices. Here, we report the realization of facile manipulation of nonlinear optical responses in the example system of MoS2 monolayer by van der Waals interfacial engineering. We found that, the interfacing of monolayer graphene will weaken the exciton oscillator strength in MoS2 monolayer and correspondingly suppress the second harmonic generation (SHG) intensity to 30% under band-gap resonance excitation. While with off-resonance excitation, the SHG intensity would enhance up to 130%, which is conjectured to be induced by the interlayer excitation between MoS2 and graphene. Our investigation provides an effective method for controlling nonlinear optical properties of two-dimensional materials and therefore facilitates their future applications in optoelectronic and photonic devices.