Ultraviolet-Ozone Treatment: an Effective Method for Fine-Tuning Optical and Electrical Properties of Suspended and Substrate-Supported MoS2

Fahrettin Sarcan*, Alex J. Armstrong, Yusuf K. Bostan, Esra Kus, Keith P. McKenna, Ayse Erol, Yue Wang*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Ultraviolet-ozone (UV-O3) treatment is a simple but effective technique for surface cleaning, surface sterilization, doping, and oxidation, and is applicable to a wide range of materials. In this study, we investigated how UV-O3 treatment affects the optical and electrical properties of molybdenum disulfide (MoS2), with and without the presence of a dielectric substrate. We performed detailed photoluminescence (PL) measurements on 1–7 layers of MoS2 with up to 8 min of UV-O3 exposure. Density functional theory (DFT) calculations were carried out to provide insight into oxygen-MoS2 interaction mechanisms. Our results showed that the influence of UV-O3 treatment on PL depends on whether the substrate is present, as well as the number of layers. Additionally, 4 min of UV-O3 treatment was found to be optimal to produce p-type MoS2, while maintaining above 80% of the PL intensity and the emission wavelength, compared to pristine flakes (intrinsically n-type). UV-O3 treatment for more than 6 min not only caused a reduction in the electron density but also deteriorated the hole-dominated transport. It is revealed that the substrate plays a critical role in the manipulation of the electrical and optical properties of MoS2, which should be considered in future device fabrication and applications.

Original languageEnglish
Article number3034
Number of pages11
Issue number23
Publication statusPublished - 27 Nov 2023

Bibliographical note

© 2023 by the authors.

Funding Information:
This research was funded by the Royal Academy of Engineering (Research Fellowship awarded to Y.W., RF\201718\17131), the Scientific Research Projects Coordination Unit of Istanbul University (FBA-2023-39412, FBG-2022-38573, FBG-2021-37896), the Scientific and Technological Research Council of Turkey (TUBITAK) project (121F169), and EPSRC (EP/R029431 and EP/X035859).


  • density functional theory (DFT)
  • doping
  • field-effect transistor
  • MoS
  • photoluminescence
  • surface treatment
  • transition metal dichalcogenide
  • ultraviolet-ozone (UV-O)

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