The Role of Oxygen Atoms on Excitons at the Edges
of Monolayer WS<sub>2</sub>
Zhenliang Hu
Jose Avila
Xinyun Wang
Jin Feng Leong
Qi Zhang
Yanpeng Liu
Maria C. Asensio
Junpeng Lu
Alexandra Carvalho
Chorng Haur Sow
Antonio Helio Castro Neto
10.1021/acs.nanolett.9b01670.s001
https://acs.figshare.com/articles/journal_contribution/The_Role_of_Oxygen_Atoms_on_Excitons_at_the_Edges_of_Monolayer_WS_sub_2_sub_/8289176
We
clarify that the chemisorption of oxygen atoms at the edges
is a key contributor to the frequently observed edge enhancement and
spatial non-uniformities of photoluminescence (PL) in WS<sub>2</sub> monolayers. Here we have investigated with momentum- and real-space
nanoimaging of the chemical and electronic density inhomogeneity of
WS<sub>2</sub> flakes. Our finding from a large panoply of techniques
together with density functional theory calculation confirms that
the oxygen chemisorption leads to the electron accumulation at the
edges. This facilitates the trion dominance of PL at the edges of
WS<sub>2</sub> flakes. Our results highlight and unravel the significance
of chemisorbed oxygen at the edges in the PL emission and electronic
structure of WS<sub>2</sub>, providing a viable path to enhance the
performance of transition-metal-dichalcogenide-based devices.
2019-06-12 00:00:00
WS 2
electron accumulation
oxygen chemisorption
real-space nanoimaging
Oxygen Atoms
chemisorbed oxygen
density inhomogeneity
edge enhancement
theory calculation
trion dominance
Monolayer WS 2
oxygen atoms
WS 2 flakes
PL emission
transition-metal-dichalcogenide-based devices
WS 2 monolayers