Rational Passivation of Sulfur Vacancy Defects in Two-Dimensional Transition Metal Dichalcogenides.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 33983711.
- Also identified by DOI 10.1021/acsnano.1c01220 and PMC identifier 8158852.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Structural defects vary the optoelectronic properties of monolayer transition metal dichalcogenides, leading to concerted efforts to control defect type and density <i>via</i> 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 <i>ab initio</i> calculations, we show that passivation of sulfur vacancy defects, which act as exciton traps in monolayer MoS<sub>2</sub> and WS<sub>2</sub>, 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.