Impurities and Electronic Property Variations of Natural MoS 2 Crystal Surfaces
Hinkle, Christopher L.
Quevedo-Lopez, Manuel A.
Alshareef, Husam N.
Hsu, Julia W P
Wallace, Robert M.
KAUST DepartmentMaterials Science and Engineering Program
Permanent link to this recordhttp://hdl.handle.net/10754/594198
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AbstractRoom temperature X-ray photoelectron spectroscopy (XPS), inductively coupled plasma mass spectrometry (ICPMS), high resolution Rutherford backscattering spectrometry (HR-RBS), Kelvin probe method, and scanning tunneling microscopy (STM) are employed to study the properties of a freshly exfoliated surface of geological MoS2 crystals. Our findings reveal that the semiconductor 2H-MoS2 exhibits both n- and p-type behavior, and the work function as measured by the Kelvin probe is found to vary from 4.4 to 5.3 eV. The presence of impurities in parts-per-million (ppm) and a surface defect density of up to 8% of the total area could explain the variation of the Fermi level position. High resolution RBS data also show a large variation in the MoSx composition (1.8 < x < 2.05) at the surface. Thus, the variation in the conductivity, the work function, and stoichiometry across small areas of MoS2 will have to be controlled during crystal growth in order to provide high quality uniform materials for future device fabrication. © 2015 American Chemical Society.
CitationAddou R, McDonnell S, Barrera D, Guo Z, Azcatl A, et al. (2015) Impurities and Electronic Property Variations of Natural MoS 2 Crystal Surfaces . ACS Nano 9: 9124–9133. Available: http://dx.doi.org/10.1021/acsnano.5b03309.
SponsorsConsejo Nacional de Ciencia y Tecnología[NL-2010-C33-149216]
Division of Electrical, Communications and Cyber Systems[ECCS-1407765]
Semiconductor Research Corporation
Defense Advanced Research Projects Agency
Microelectronics Advanced Research Corporation
Texas Instruments Distinguished Chair in Nanoelectronics, University of Texas at Dallas
Center for Low Energy Systems Technology, University of Notre Dame
PublisherAmerican Chemical Society (ACS)