MRS Meetings and Events

 

NM06.12.04 2022 MRS Fall Meeting

Probing Sulfur Vacancies in MoS2 by Photoluminescence

When and Where

Dec 2, 2022
8:45am - 9:00am

Hynes, Level 2, Room 207

Presenter

Co-Author(s)

Yiru Zhu1,Yan Wang1,Soumya Sarkar1,Juhwan Lim1,Zhepeng Zhang2,Goki Eda2,Robert Hoye3,Manish Chhowalla1

University of Cambridge1,National University of Singapore2,Imperial College London3

Abstract

Yiru Zhu1,Yan Wang1,Soumya Sarkar1,Juhwan Lim1,Zhepeng Zhang2,Goki Eda2,Robert Hoye3,Manish Chhowalla1

University of Cambridge1,National University of Singapore2,Imperial College London3
Chalcogen vacancies can influence the electronic structure of 2D transition metal dichalcogenides (TMDs) by introducing mid-gap defect states. A relatively simple way to create chalcogen vacancies is by thermal annealing. The vacancy defects are optically active and can be probed by photoluminescence (PL) spectroscopy. In this study, we annealed mechanically exfoliated monolayer MoS<sub>2</sub> in different atmospheres and probed the sulfur vacancy states by PL. In nitrogen or argon atmosphere, room temperature defect emission is absent. However, annealing in hydrogen/argon (5% H<sub>2</sub>) gives rise to room-temperature defect PL peak at 1.72 eV. Stronger defect PL signal at 10K is observed when annealing time is increased. We show that sulfur vacancies can be passivated by annealing in sulfur vapor. X-ray photoemission spectroscopy is used to confirm the creation and passivation of sulfur vacancies. Our results suggest that defect states introduced by sulfur vacancies act as trapping centres for radiative recombination and can be passivated by annealing in sulfur vapor environment.

Keywords

defects

Symposium Organizers

Nicholas Glavin, Air Force Research Laboratory
Aida Ebrahimi, The Pennsylvania State University
SungWoo Nam, University of California, Irvine
Won Il Park, Hanyang University

Symposium Support

Bronze
MilliporeSigma

Publishing Alliance

MRS publishes with Springer Nature