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  • Physical adsorption and oxidation of ultra-thin MoS 2 crystals: insights into surface engineering for 2D electronics and beyond
Title: Physical adsorption and oxidation of ultra-thin MoS 2 crystals: insights into surface engineering for 2D electronics and beyond
Abstract The oxidation mechanism of atomically thin molybdenum disulfide (MoS 2 ) plays a critical role in its nanoelectronics, optoelectronics, and catalytic applications, where devices often operate in an elevated thermal environment. In this study, we systematically investigate the oxidation of mono- and few-layer MoS 2 flakes in the air at temperatures ranging from 23 °C to 525 °C and relative humidities of 10%–60% by using atomic force microscopy (AFM), Raman spectroscopy and x-ray photoelectron spectroscopy. Our study reveals the formation of a uniform nanometer-thick physical adsorption layer on the surface of MoS 2 , which is attributed to the adsorption of ambient moisture. This physical adsorption layer acts as a thermal shield of the underlying MoS 2 lattice to enhance its thermal stability and can be effectively removed by an AFM tip scanning in contact mode or annealing at 400 °C. Our study shows that high-temperature thermal annealing and AFM tip-based cleaning result in chemical adsorption on sulfur vacancies in MoS 2 , leading to p-type doping. Our study highlights the importance of humidity control in ensuring reliable and optimal performance for MoS 2 -based electronic and electrochemical devices and provides crucial insights into the surface engineering of MoS 2 , which are relevant to the study of other two-dimensional transition metal dichalcogenide materials and their applications.  more » « less
Award ID(s):
2006127
PAR ID:
10443213
Author(s) / Creator(s):
; ; ; ; ;
Date Published:
Journal Name:
Nanotechnology
Volume:
34
Issue:
40
ISSN:
0957-4484
Page Range / eLocation ID:
405701
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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