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arXiv · 2003.02352

Probing the Electronic Properties of Monolayer MoS$_2$ via Interaction with Molecular Hydrogen

Natália P. Rezende·Alisson R. Cadore·Andreij C. Gadelha·Cíntia L. Pereira·Vinicius Ornelas·Kenji Watanabe·Takashi Taniguchi·André S. Ferlauto·Ângelo Malachias·Leonardo C. Campos·Rodrigo G. Lacerda
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Abstract

This work presents a detailed experimental investigation of the interaction between molecular hydrogen (H$_2$) and monolayer MoS$_2$ field effect transistors (MoS$_2$ FET), aiming for sensing application. The MoS$_2$ FET exhibits a response to H$_2$ that covers a broad range of concentration (0.1 - 90%) at a relatively low operating temperature range (300-473 K). Most important, H$_2$ sensors based on MoS$_2$ FETs show desirable properties such as full reversibility and absence of catalytic metal dopants (Pt or Pd). The experimental results indicate that the conductivity of MoS$_2$ monotonically increases as a function of the H$_2$ concentration due to a reversible charge transferring process. It is proposed that such process involves dissociative H$_2$ adsorption driven by interaction with sulfur vacancies in the MoS$_2$ surface (VS). This description is in agreement with related density functional theory studies about H$_2$ adsorption on MoS$_2$. Finally, measurements on partially defect-passivated MoS$_2$ FETs using atomic layer deposited aluminum oxide consist of an experimental indication that the VS plays an important role in the H$_2$ interaction with the MoS$_2$. These findings provide insights for futures applications in catalytic process between monolayer MoS$_2$ and H$_2$ and also introduce MoS$_2$ FETs as promising H$_2$ sensors.

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Natália P. Rezende, Alisson R. Cadore, Andreij C. Gadelha, Cíntia L. Pereira, Vinicius Ornelas, Kenji Watanabe, Takashi Taniguchi, André S. Ferlauto, Ângelo Malachias, Leonardo C. Campos, Rodrigo G. Lacerda. 2020-03-04. Probing the Electronic Properties of Monolayer MoS$_2$ via Interaction with Molecular Hydrogen. https://doi.org/10.1002/aelm.201800591

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