上海科技大学知识管理系统

In order to explore the potential of 2D materials in the application field of on-chip tunable active optical devices, a strain-tunable light source with monolayer MoSe2 was produced. High quality monolayer MoSe2 was obtained by micromechanical exfoliation method. The all-dry transfer method was used to transfer monolayer MoSe2 to biaxial piezoelectric ceramics coated with 150 nm thick Polymethylmethacrylate. The electric field was applied to the biaxial piezoelectric ceramic, which converts the electrical signal into the strain signal, to controll the optical properties of MoSe2. The variation of intrinsic exciton and charge exciton peaks of the MoSe2 with strain tuning were observed from photoluminescence spectra at low temperature of ~5 K. The results indicate that blueshifts of ~3.8 meV and ~3.7 meV appear in the intrinsic exciton and charge exciton peaks, respectively, when the strain is tuned from tension to compression. And increasing compressive strain or tensile strain will decrease the intensity of intrinsic exciton and charge exciton peak linearly. At the same time, the circular polarization degree of the emission related to the circular polarization of the pump laser also shows regular change with the variation of strain. This research confirms the close correlation between the stain tuning and the optical properties of monolayer MoSe2. It provides support for the development of various on-chip tunable active optical devices based on 2D materials.
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