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arXiv · 1807.07592

Dielectric Properties and Ion Transport in Layered MoS_{2} Grown by Vapor-Phase Sulfurization

M. Belete·S. Kataria·U. Koch·M. Kruth·C. Engelhard·J. Mayer·O. Engström·M. C. Lemme
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Abstract

Electronic and dielectric properties of vapor-phase grown MoS_{2} have been investigated in metal/MoS_{2}/silicon capacitor structures by capacitance-voltage and conductancevoltage techniques. Analytical methods confirm the MoS_{2} layered structure, the presence of interfacial silicon oxide (SiO_{x}) and the composition of the films. Electrical characteristics in combination with theoretical considerations quantify the concentration of electron states at the interface between Si and a 2.5 - 3 nm thick silicon oxide interlayer between Si and MoS_{2}. Measurements under electric field stress indicate the existence of mobile ions in MoS_{2} that interact with interface states. Based on time-offlight secondary ion mass spectrometry, we propose OH^{-} ions as probable candidates responsible for the observations. The dielectric constant of the vapor-phase grown MoS_{2} extracted from CV measurements at 100 KHz is in the range of 2.6 to 2.9. The present study advances the understanding of defects and interface states in MoS_{2}. It also indicates opportunities for ion-based plasticity in 2D material devices for neuromorphic computing applications.

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M. Belete, S. Kataria, U. Koch, M. Kruth, C. Engelhard, J. Mayer, O. Engström, M. C. Lemme. 2018-07-19. Dielectric Properties and Ion Transport in Layered MoS_{2} Grown by Vapor-Phase Sulfurization. https://doi.org/10.1021/acsanm.8b01412

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