Active Light Control of the MoS2 Monolayer Exciton Binding Energy

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• 作者：Ziwei Li ; Yingdong Xiao ; Yongji Gong ; Zongpeng Wang ; Yimin Kang ; Shuai Zu ; Pulickel M. Ajayan ; Peter Nordlander ; Zheyu Fang
• 刊名：ACS Nano
• 出版年：2015
• 出版时间：October 27, 2015
• 年：2015
• 卷：9
• 期：10
• 页码：10158-10164
• 全文大小：568K
• ISSN：1936-086X

文摘

Plasmonic excitation of Au nanoparticles deposited on a MoS₂ monolayer changes the absorption and photoluminescence characteristics of the material. Hot electrons generated from the Au nanoparticles are transferred into the MoS₂ monolayers, resulting in n-doping. The doping effect of plasmonic hot electrons modulates the dielectric permittivity of materials, resulting in a red shift of both the absorption and the photoluminescence spectrum. This spectroscopic tuning was further investigated experimentally by using different Au nanoparticle concentrations, excitation laser wavelengths, and intensities. An analytical model for the photoinduced modulation of the MoS₂ dielectric function and its exciton binding energy change is developed and used to estimate the doping density of plasmonic hot electrons. Our approach is important for the development of photonic devices for active control of light by light.