Abstract

Because the surface-to-volume ratio of quasi-two-dimensional materials is extremely high, understanding their surface characteristics is crucial for practically controlling their intrinsic properties and fabricating p-type and n-type layered semiconductors. Van der Waals crystals are expected to have an inert surface because of the absence of dangling bonds. However, here we show that the surface of high-quality synthesized molybdenum disulfide (MoS2) is a major n-doping source. The surface electron concentration of MoS2 is nearly four orders of magnitude higher than that of its inner bulk. Substantial thickness-dependent conductivity in MoS2 nanoflakes was observed. The transfer length method suggested the current transport in MoS2 following a two-dimensional behavior rather than the conventional three-dimensional mode. Scanning tunneling microscopy and angle-resolved photoemission spectroscopy measurements confirmed the presence of surface electron accumulation in this layered material. Notably, the in situ-cleaved surface exhibited a nearly intrinsic state without electron accumulation.

Details

Title
Two-dimensional electronic transport and surface electron accumulation in MoS2
Author
Siao, M D 1 ; Shen, W C 2 ; Chen, R S 1   VIAFID ORCID Logo  ; Chang, Z W 3 ; Shih, M C 4 ; Chiu, Y P 5   VIAFID ORCID Logo  ; C-M, Cheng 6 

1  Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, Taipei, Taiwan 
2  Department of Electronic Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan 
3  Department of Physics, National Taiwan Normal University, Taipei, Taiwan 
4  Department of Physics, National Taiwan University, Taipei, Taiwan 
5  Department of Physics, National Taiwan Normal University, Taipei, Taiwan; Department of Physics, National Taiwan University, Taipei, Taiwan 
6  National Synchrotron Radiation Research Center, Hsinchu, Taiwan; Department of Physics, National Sun Yat-Sen University, Kaohsiung, Taiwan 
Pages
1-12
Publication year
2018
Publication date
Apr 2018
Publisher
Nature Publishing Group
e-ISSN
20411723
Source type
Scholarly Journal
Language of publication
English
DOI
https://doi.org/10.1038/s41467-018-03824-6
ProQuest document ID
2024453111
Copyright
© 2018. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.