[16p-B414-1~16] 17.3 Layered materials

△ [16p-B414-8] Second-order nonlinear optical response of excitons in hBN-encapsulated monolayer transition metal dichalcogenides

〇Shinya Takahshi¹, Satoshi Kusaba¹, Kenji Watanabe², Takashi Taniguchi², Kazuhiro Yanagi³, Koichiro Tanaka^1,4 (1.Kyoto Univ., 2.NIMS, 3.Tokyo Metro. Univ., 4.iCeMS, Kyoto Univ.)

Keywords:monolayer transition metal dichalcogenides, exciton, nonlinear spectroscopy

We observed 1s, 2p, and other levels of excitons in hBN-encapsulated monolayer MoS₂, MoSe₂, WS₂, and WSe₂ by using sum frequency generation spectroscopy. From polarization dependences, proportion of sum frequency generation in 1s exciton peaks was found to be larger in MoX₂ than in WX₂ . In the presentation, we will give discussion on the results by considering exciton level structures and relaxation processes.