Chemical Selectivity at Grain Boundary Dislocations in Monolayer Mo1-xWxS2 Transition Metal Dichalcogenides

Ziqian Wang; Yuhao Shen; Shoucong Ning; Yoshikazu Ito; Pan Liu; Zheng Tang; Takeshi Fujita; Akihiko Hirata; Mingwei Chen

doi:10.1021/acsami.7b08945

Chemical Selectivity at Grain Boundary Dislocations in Monolayer Mo_1-xW_xS₂ Transition Metal Dichalcogenides

ACS Appl Mater Interfaces. 2017 Sep 6;9(35):29438-29444. doi: 10.1021/acsami.7b08945. Epub 2017 Aug 24.

Authors

Ziqian Wang^{1

2}, Yuhao Shen³, Shoucong Ning⁴, Yoshikazu Ito⁵, Pan Liu⁶, Zheng Tang³, Takeshi Fujita², Akihiko Hirata², Mingwei Chen^{1

2

6

7}

Affiliations

¹ Department of Materials Science and Engineering, Johns Hopkins University , Baltimore, Maryland 21218, United States.
² Advanced Institute for Materials Research, Tohoku University , Sendai 980-8577, Japan.
³ Key Laboratory of Polar Materials and Devices, East China Normal University , Shanghai 200062, P. R. China.
⁴ Department of Mechanical and Aerospace Engineering, School of Engineering, Hong Kong University of Science and Technology , Clear Water Bay, Kowloon, Hong Kong SAR.
⁵ Institute of Applied Physics, Graduate School of Pure and Applied Sciences, University of Tsukuba , Tsukuba 305-8573, Japan.
⁶ State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University , Shanghai 200030, P.R. China.
⁷ CREST, Japan Science and Technology Agency , 4-1-8 Honcho Kawaguchi, Saitama 332-0012, Japan.

PMID: 28819970
DOI: 10.1021/acsami.7b08945

Abstract

Grain boundaries (GBs) are unavoidable crystal defects in polycrystalline materials and significantly influence their properties. However, the structure and chemistry of GBs in 2D transition metal dichalcogenide alloys have not been well established. Here we report significant chemical selectivity of transition metal atoms at GB dislocation cores in Mo_1-xW_xS₂ monolayers. Different from classical elastic field-driven dislocation segregation in bulk crystals, the chemical selectivity in the 2D crystals originates prominently from variation of atomic coordination numbers at dislocation cores. This observation provides atomic insights into the topological effect on the chemistry of crystal defects in 2D materials.

Keywords: chemical selectivity; dislocation; grain boundary; transition metal dichalcogenide; two-dimensional materials.