Anisotropic point defects in rhenium diselenide monolayers
Yong Zhu,
Lei Tao,
Xiya Chen,
Yinhang Ma,
Shoucong Ning,
Jiadong Zhou,
Xiaoxu Zhao,
Michel Bosman,
Zheng Liu,
Shixuan Du,
Sokrates T. Pantelides,
Wu Zhou
Affiliations
Yong Zhu
School of Physical Sciences and CAS Key Laboratory of Vacuum Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
Lei Tao
School of Physical Sciences and CAS Key Laboratory of Vacuum Sciences, University of Chinese Academy of Sciences, Beijing 100049, China; Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
Xiya Chen
School of Physical Sciences and CAS Key Laboratory of Vacuum Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
Yinhang Ma
School of Physical Sciences and CAS Key Laboratory of Vacuum Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
Shoucong Ning
Department of Materials Science and Engineering, National University of Singapore, Singapore 117575, Singapore
Jiadong Zhou
School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore
Xiaoxu Zhao
School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore
Michel Bosman
Department of Materials Science and Engineering, National University of Singapore, Singapore 117575, Singapore
Zheng Liu
School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore
Shixuan Du
Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China; CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100049, China; Songshan Lake Materials Laboratory, Dongguan 523808, China; Corresponding author
Sokrates T. Pantelides
Department of Physics and Astronomy and Department of Electrical and Computer Engineering, Vanderbilt University, Nashville, TN 37235, USA
Wu Zhou
School of Physical Sciences and CAS Key Laboratory of Vacuum Sciences, University of Chinese Academy of Sciences, Beijing 100049, China; CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100049, China; Corresponding author
Summary: Point defects in 1T″ anisotropic ReSe2 offer many possibilities for defect engineering, which could endow this two-dimensional semiconductor with new functionalities, but have so far received limited attention. Here, we systematically investigate a full spectrum of point defects in ReSe2, including vacancies (VSe1-4), isoelectronic substitutions (OSe1-4 and SSe1-4), and antisite defects (SeRe1-2 and ReSe1-4), by atomic-scale electron microscopy imaging and density functional theory (DFT) calculations. Statistical counting reveals a diverse density of various point defects, which are further elaborated by the formation energy calculations. Se vacancy dynamics was unraveled by in-situ electron beam irradiation. DFT calculations reveal that vacancies at Se sites notably introduce in-gap states, which are largely quenched upon isoelectronic substitutions (O and S), whereas antisite defects introduce localized magnetic moments. These results provide atomic-scale insight of atomic defects in 1T″-ReSe2, paving the way for tuning the electronic structure of anisotropic ReSe2 via defect engineering.
