In:
Advanced Materials, Wiley, Vol. 31, No. 23 ( 2019-06)
Abstract:
Alloying 2D transition metal dichalcogenides has opened up new opportunities for bandgap engineering and phase control. Developing a simple and scalable synthetic route is therefore essential to explore the full potential of these alloys with tunable optical and electrical properties. Here, the direct synthesis of monolayer WTe 2 x S 2(1− x ) alloys via one‐step chemical vapor deposition (CVD) is demonstrated. The WTe 2 x S 2(1− x ) alloys exhibit two distinct phases (1H semiconducting and 1T ′ metallic) under different chemical compositions, which can be controlled by the ratio of chalcogen precursors as well as the H 2 flow rate. Atomic‐resolution scanning transmission electron microscopy–annular dark field (STEM‐ADF) imaging reveals the atomic structure of as‐formed 1H and 1T ′ alloys. Unlike the commonly observed displacement of metal atoms in the 1T ′ phase, local displacement of Te atoms from original 1H lattice sites is discovered by combined STEM‐ADF imaging and ab initio molecular dynamics calculations. The structure distortion provides new insights into the structure formation of alloys. This generic synthetic approach is also demonstrated for other telluride‐based ternary monolayers such as WTe 2 x Se 2(1− x ) single crystals.
Type of Medium:
Online Resource
ISSN:
0935-9648
,
1521-4095
DOI:
10.1002/adma.201900862
Language:
English
Publisher:
Wiley
Publication Date:
2019
detail.hit.zdb_id:
1474949-X
