1. Rational Passivation of Sulfur Vacancy Defects in Two-Dimensional Transition Metal Dichalcogenides
- Author
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Jack A. Alexander-Webber, Ye Fan, Steven G. Louie, Arelo Tanoh, Akshay Rao, Samuel D. Stranks, Géraud Delport, Stephan Hofmann, Sivan Refaely-Abramson, Cyan A. Williams, Hope M. Bretscher, Diana Y. Qiu, Jeffrey B. Neaton, Zhaojun Li, James Xiao, Bretscher, Hope [0000-0001-6551-4721], Qiu, Diana Yuan [0000-0003-3067-6987], Refaely-Abramson, Sivan [0000-0002-7031-8327], Alexander-Webber, Jack A [0000-0002-9374-7423], Tanoh, Arelo [0000-0003-2494-5984], Stranks, Samuel D [0000-0002-8303-7292], Hofmann, Stephan [0000-0001-6375-1459], Louie, Steven G [0000-0003-0622-0170], Rao, Akshay [0000-0003-4261-0766], Apollo - University of Cambridge Repository, and Apollo-University Of Cambridge Repository
- Subjects
spectroscopy ,Materials science ,Photoluminescence ,Passivation ,Exciton ,General Physics and Astronomy ,Physics::Optics ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Article ,Condensed Matter::Materials Science ,defect engineering ,Transition metal ,Ab initio quantum chemistry methods ,Vacancy defect ,Monolayer ,General Materials Science ,Nanoscience & Nanotechnology ,Spectroscopy ,defects ,General Engineering ,many-body perturbation theory ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,2D materials ,0104 chemical sciences ,Chemical physics ,TMDC ,0210 nano-technology ,Den kondenserade materiens fysik - 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.
- Published
- 2021