Layer-Number-Dependent Exciton Recombination Behaviors of MoS2 Determined by Fluorescence-Lifetime Imaging Microscopy

作者：Wang, Ting; Zhang, Yirui; Liu, Yuanshuang; Li, Junyi; Liu, Dameng^*; Luo, Jianbin^*; Ge, Kai

来源：Journal of Physical Chemistry C, 2018, 122(32): 18651-18658.

DOI：10.1021/acs.jpcc.8b02393

• ELECTRONIC-STRUCTURE
• BAND-STRUCTURE
• MONO LAYER
• PHOTOLUMINESCENCE
• MONOLAYER
• WSE2
• BULK

The fluorescence-lifetime imaging microscopy (FLIM) technique is utilized to probe the photoluminescence properties of individual MoS2 flakes. This measurement allows identification of the layer number of the flakes: two fluorescence decay lifetimes (tau(1) and tau(2)) exhibit linear relationships with the layer number. Our investigation of the fluorescence lifetime reveals exciton dynamics in monolayer and multilayers MoS2. We find the distinct difference on the decay rates between A exciton (fast) and B exciton (slow). K'/Gamma emission has different decay behaviors with respect to the layer number (N) because of its variable energy in monolayer and multilayer samples. The interplay of these transition channels also plays an important impact on the overall decay. Our results demonstrate that FLIM is an effective measurement for studying the luminescence properties of transition metal dichalcogenides.

• 出版日期2018-8-16
• 单位清华大学