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Recoil Effect and Photoemission Splitting of Trions in Monolayer MoS2

Authors :
Qicheng Zhang
Minghao Zhuang
Aldrine Abenoja Cagang
Zhengtang Luo
Ruizhe Wu
Meng-Qiang Zhao
Irfan Haider Abidi
Yao Ding
Xuewu Ou
Zhaoli Gao
Carl H. Naylor
Source :
ACS Nano. 11:10808-10815
Publication Year :
2017
Publisher :
American Chemical Society (ACS), 2017.

Abstract

The 2D geometry nature and low dielectric constant in transition-metal dichalcogenides lead to easily formed strongly bound excitons and trions. Here, we studied the photoluminescence of van der Waals heterostructures of monolayer MoS2 and graphene at room temperature and observed two photoluminescence peaks that are associated with trion emission. Further study of different heterostructure configurations confirms that these two peaks are intrinsic to MoS2 and originate from a bound state and Fermi level, respectively, of which both accept recoiled electrons from trion recombination. We demonstrate that the recoil effect allows us to electrically control the photon energy of trion emission by adjusting the gate voltage. In addition, significant thermal smearing at room temperature results in capture of recoil electrons by bound states, creating photoemission peak at low doping level whose photon energy is less sensitive to gate voltage tuning. This discovery reveals an unexpected role of bound states for ...

Details

ISSN :
1936086X and 19360851
Volume :
11
Database :
OpenAIRE
Journal :
ACS Nano
Accession number :
edsair.doi...........45433579f74cc4b88e8af436ace0045c
Full Text :
https://doi.org/10.1021/acsnano.7b03457