Rational Passivation of Sulfur Vacancy Defects in Two-Dimensional Transition Metal Dichalcogenides.


Type
Article
Change log
Authors
Li, Zhaojun 
Xiao, James 
Refaely-Abramson, Sivan  ORCID logo  https://orcid.org/0000-0002-7031-8327
Abstract

Structural defects vary the optoelectronic properties of monolayer transition metal dichalcogenides, leading to concerted efforts to control defect type and density via materials growth or postgrowth passivation. Here, we explore a simple chemical treatment that allows on-off switching of low-lying, defect-localized exciton states, leading to tunable emission properties. Using steady-state and ultrafast optical spectroscopy, supported by ab initio calculations, we show that passivation of sulfur vacancy defects, which act as exciton traps in monolayer MoS2 and WS2, allows for controllable and improved mobilities and an increase in photoluminescence up to 275-fold, more than twice the value achieved by other chemical treatments. Our findings suggest a route for simple and rational defect engineering strategies for tunable and switchable electronic and excitonic properties through passivation.

Description
Keywords
2D materials, TMDC, defect engineering, defects, many-body perturbation theory, spectroscopy
Journal Title
ACS Nano
Conference Name
Journal ISSN
1936-0851
1936-086X
Volume Title
Publisher
American Chemical Society (ACS)
Rights
All rights reserved
Sponsorship
Engineering and Physical Sciences Research Council (EP/M006360/1)
European Research Council (758826)
Royal Commission for the Exhibition of 1851 (RF474/2016)
Royal Society (DHF\F1\191163)
European Research Council (756962)