| In recent years,transition-metal dichalcogenides（TMDCs）have been studied and widely used in photocatalysis,ultrafast lasers,and high performance optoelectronic devices,owing to their excellent optical and electrical properties.In this paper,we work on the carrier dynamics characteristics based on the Photoluminescence-Raman spectroscopy（PRS）and transient absorption properties of TMDCs（MoS2、ReS2）and their heterostructures（MoS2/ReS2）.Thepractical work is as followed:1.We have investigated the ultrafast optical properties of carriers in low-dimensional MoS2 under room temperature and large influence conditions.First,we studied ultrafast relaxation characteristics of MoS2 in different influence conditions,by measuring their optical properties with Photoluminescence-Raman spectroscopy（PRS）and transient absorption spectroscopy（TAS）.We find the intense exciton energy can be renormalized in different layer thickness materials.Furthermore,we studied the carrier dynamics of the renormalization in low-dimensional MoS2.2.We performed PRS and TAS to study the ultrafast relaxation of anisotropic ReS2in different polarization conditions.First,we carried out pramitive tests on the polarization exciton properties of anisotropic ReS2 using PRS,and find out the relationship between polarized excitons and b axis.We also utilized TAS to characterize the carrier dynamics of different axial directions,which imply the relaxation of the polarized excitons.3.We carried out experiments the physics of low-dimensional MoS2/ReS2heterostructures.Through the characterization of low-dimensional MoS2/ReS2heterostructures using PRS,we find that the heterojunction structure can lead to the anisotropy of the energy transfer efficiency.To demonstrate,we measured the spactra of the anisotropic low-dimensional MoS2/ReS2 heterojunction with TAS.The TAS results show that the energy transfer time is affected by the heterojunction structure,which can explain the anisotropic energy transfer enfficiency in return. |
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