Berlin 2018 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 13: Poster Session I

HL 13.8: Poster

Montag, 12. März 2018, 17:30–19:30, Poster B

Influence of oxygen and water on the stability and optical properties of monolayer MoS₂ — •Christian Tessarek, Oleg Gridenco, Kathrin Sebald, Stephan Figge, Jürgen Gutowski, and Martin Eickhoff — Institute of Solid State Physics, University of Bremen, Otto-Hahn-Allee 1, D-28359 Bremen, Germany

2D materials such as graphene, BN and transition metal dichalcogenides (TMDs) are promising candidates for further miniaturization of (opto-)electronic devices. Monolayer MoS₂, a member of the TMD family, is a semiconductor with a direct band gap of 1.9 eV and thus suitable for transistor, photovoltaic and light emitting applications. Its large surface-to-volume ratio and chemical activity enables strong interaction with the environment essential for highly sensitive optical sensors. In this context it is necessary to understand the influence of the environment on the optical properties of MoS₂.

In this study, thin layers are prepared by exfoliation of bulk MoS₂. Raman spectroscopy is used to identify the number of layers and photoluminescence measurements are performed to investigate the influence of different gases and liquids on the optical properties of mono- and multilayer MoS₂. A strong enhancement of the photoluminescence intensity is achieved by exposing MoS₂ to oxygen and water. It is found that MoS₂ is more stable in oxygen compared to water. Degradation mechanism are analyzed by Raman spectroscopy.