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Epitaxial Growth of Single‐Phase 1T'‐WSe 2 Monolayer with Assistance of Enhanced Interface Interaction
Author(s) -
Chen Wang,
Hu Mengli,
Zong Junyu,
Xie Xuedong,
Meng Qinghao,
Yu Fan,
Wang Li,
Ren Wei,
Chen Aixi,
Liu Gan,
Xi Xiaoxiang,
Li FangSen,
Sun Jian,
Liu Junwei,
Zhang Yi
Publication year - 2021
Publication title -
advanced materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.707
H-Index - 527
eISSN - 1521-4095
pISSN - 0935-9648
DOI - 10.1002/adma.202004930
Subject(s) - scanning tunneling microscope , monolayer , materials science , topological insulator , photoemission spectroscopy , epitaxy , condensed matter physics , molecular beam epitaxy , scanning tunneling spectroscopy , phase (matter) , metastability , topological order , nanotechnology , chemical physics , optoelectronics , topology (electrical circuits) , quantum , x ray photoelectron spectroscopy , physics , nuclear magnetic resonance , combinatorics , mathematics , layer (electronics) , quantum mechanics
The WSe 2 monolayer in 1T’ phase is reported to be a large‐gap quantum spin Hall insulator, but is thermodynamically metastable and so far the fabricated samples have always been in the mixed phase of 1T’ and 2H, which has become a bottleneck for further exploration and potential applications of the nontrivial topological properties. Based on first‐principle calculations in this work, it is found that the 1T’ phase could be more stable than 2H phase with enhanced interface interactions. Inspired by this discovery, SrTiO 3 (100) is chosen as substrate and WSe 2 monolayer is successfully grown in a 100% single 1T’ phase using the molecular beam epitaxial method. Combining in situ scanning tunneling microscopy and angle‐resolved photoemission spectroscopy measurements, it is found that the in‐plane compressive strain in the interface drives the 1T'‐WSe 2 into a semimetallic phase. Besides providing a new material platform for topological states, the results show that the interface interaction is a new approach to control both the structure phase stability and the topological band structures of transition metal dichalcogenides.