| AVS 63rd International Symposium & Exhibition | |
| 2D Materials Focus Topic | Monday Sessions |
| Session 2D+MI-MoA |
| Session: | Dopants, Defects and Interfaces in 2D Materials |
| Presenter: | Hui Zhu, University of Texas at Dallas |
| Authors: | H. Zhu, University of Texas at Dallas X. Qin, University of Texas at Dallas L. Cheng, University of Texas at Dallas A. Azcatl, University of Texas at Dallas J. Kim, University of Texas at Dallas R.M. Wallace, University of Texas at Dallas |
| Correspondent: | Click to Email |
Molybdenum disulfide (MoS2), a representative layered transition metal dichalcogenide, has obtained considerable research interest in recent years, due to its promising mechanical, electronic, and photonic properties.1,2 The mechanical exfoliation of MoS2 has led to an intensive research on thin film field-effect transistors made with MoS2 flakes.3,4 However, the scalable layer engineering of MoS2 flakes is still a challenge for device fabrication. In this work, a novel MoS2 functionalization and layer thinning process is presented by combining the surface oxidation of MoS2 with a remote O2 plasma to form an amorphous MoOx layer and subsequent annealing to selectively desorb the MoOx surface layer. Exfoliated MoS2 is shown to chemically oxidize in a layered manner upon exposure to the remote O2 plasma. X-ray photoelectron spectroscopy (XPS), low energy electron diffraction (LEED), and atomic force microscopy (AFM) are employed to characterize the surface chemistry, structure and topography of the oxidation process, and indicates that the oxidation mainly occurs on the topmost layer without altering the chemical composition of underlying layer. After the desorption of MoOx by the annealing at 500 °C, a clean, flat and chemically undisturbed MoS2 surface as evidenced from XPS, LEED, AFM and scanning tunneling microscopy (STM) characterization. This work renders promising atomic scale fabrication applications such as surface functionalization, charging engineering and atomic layer etching.
This work was supported in part by the SWAN Center, a SRC center sponsored by the Nanoelectronics Research Initiative and NIST, the Center for Low Energy Systems Technology (LEAST), one of the six SRC STARnet Centers, sponsored by MARCO and DARPA, and the US/Ireland R&D Partnership (UNITE) under the NSF award ECCS-1407765.
Reference
1 T. Cao, G. Wang, W. Han, H. Ye, C. Zhu, J. Shi, Q. Niu, P. Tan, E. Wang, B. Liu, and J. Feng, Nat. Commun. 3, 887 (2012).
2 B. Radisavljevic, A. Radenovic, J. Brivio, V. Giacometti, and A. Kis, Nat. Nanotechnol. 6, 147 (2011).
3 M.S. Fuhrer and J. Hone, Nat. Nanotechnol. 8, 146 (2013).
4 S. Kim, A. Konar, W.-S. Hwang, J.H. Lee, J. Lee, J. Yang, C. Jung, H. Kim, J.-B. Yoo, J.-Y. Choi, Y.W. Jin, S.Y. Lee, D. Jena, W. Choi, and K. Kim, Nat. Commun. 3, 1011 (2012).