Format

Send to

Choose Destination
Nanoscale. 2017 Nov 30;9(46):18546-18551. doi: 10.1039/c7nr05174c.

Coupled relaxation channels of excitons in monolayer MoSe2.

Author information

1
Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, Collaborative Innovation Center of Advanced Microstructures, School of Electronic Science and Engineering, Nanjing University, Nanjing 210093, People's Republic of China. xzruan@nju.edu.cn fwang@nju.edu.cn ybxy@nju.edu.cn.

Abstract

Using ultrafast degenerate pump-probe spectroscopy, we have investigated the ultrafast exciton dynamics of monolayer MoSe2 at different pump fluences. The exciton-exciton annihilation, typically occurring tens of picoseconds after pump excitation, has been found to have a substantial correlation with the initial relaxation process dominated by the defect trapping of excitons. A new exciton-exciton annihilation model has been proposed by introducing a coupling term that accounts for the initial relaxation contribution. This coupling term can be tuned by varying the pump excitation intensity and at a high intensity it vanishes due to the full occupation of the defect states. At the same time, the final electron-hole recombination is found to be affected by the heat accumulation effect originating from the high intensity pump pulses.

PMID:
29164206
DOI:
10.1039/c7nr05174c

Supplemental Content

Full text links

Icon for Royal Society of Chemistry
Loading ...
Support Center