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Nano Research

Article Title

van der Waals epitaxial growth of ultrathin metallic NiSe nanosheets on WSe2 as high performance contacts for WSe2 transistors

Authors

Bei Zhao, Hunan Key Laboratory of Two-Dimensional Materials, State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China
Weiqi Dang, Hunan Key Laboratory of Two-Dimensional Materials, State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China
Xiangdong Yang, Hunan Key Laboratory of Two-Dimensional Materials, State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China
Jia Li, Hunan Key Laboratory of Two-Dimensional Materials, State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China
Haihong Bao, Center for Electron Microscopy Institute for New Energy Materials and Low-Carbon Technologies School of Materials, Tianjin University of Technology, Tianjin 300384, China
Kai Wang, Center for Electron Microscopy Institute for New Energy Materials and Low-Carbon Technologies School of Materials, Tianjin University of Technology, Tianjin 300384, China
Jun Luo, Center for Electron Microscopy Institute for New Energy Materials and Low-Carbon Technologies School of Materials, Tianjin University of Technology, Tianjin 300384, China
Zhengwei Zhang, Hunan Key Laboratory of Two-Dimensional Materials, State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China
Bo Li, School of Physics and Electronics, Hunan University, Changsha 410082, China
Haipeng Xie, Hunan Key Laboratory of Super-microstructure and Ultrafast Process, College of Physics and Electronics, Central South University, Changsha 410083, China
Yuan Liu, School of Physics and Electronics, Hunan University, Changsha 410082, China
Xidong Duan, Hunan Key Laboratory of Two-Dimensional Materials, State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China

Keywords

in situ growth, nonlayered NiSe nanosheets, Schottky barrier, metal-semiconductor junctions, chemical vapor deposition

Abstract

A prerequisite for widespread applications of atomically thin transition metal dichalcogenides in future electronics is to achieve reliable electrical contacts, which is of considerable challenge due to the difficulties in selectively doping and inevitable physical damages of these atomically thin materials during typical metal integration process. Here, we report the in situ growth of ultrathin metallic NiSe single crystals on WSe2 in which the metallic NiSe nanosheets function as the contact electrodes to WSe2, creating an interface that is essentially free from chemical disorder. The NiSe/WSe2 heterostructures also exhibit well-aligned lattice orientation between the two layers, forming a periodic Moiré pattern. Electrical transport studies demonstrate that the NiSe nanosheets exhibit an excellent metallic feature, as evidenced by the extra-high electrical conductivity of up to 1.6×106 S·m−1. The WSe2 transistors with the NiSe contact show field-effect mobilities (μFE) more than double that with Cr/Au electrodes. This study demonstrates an effective pathway to achieve reliable electrical contacts to the atomically thin 2D materials, and maybe readily extended for fabricating 2D/2D low-resistance contacts for a variety of transition metal dichalcogenides.

Graphical Abstract

Publisher

Tsinghua University Press

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