Van der Waals Epitaxy of p-type MoO2 Film on Mica for Flexible Electronics
C. H. Ma1,2*, J. C. Lin3, H. J. Liu2, T. H. Do2, Y. M. Zhu4, Q. Zhan4, P. W. Chiu1,6, Y. H. Chu2,3,5
1Institute of Electronics Engineering, National Tsing Hua University, Hsinchu, Taiwan
2Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu, Taiwan
3Institute of Physics, Academia Sinica, Taipei, Taiwan
4School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, China
5Department of Electrophysics, National Chiao Tung University, Hsinchu, Taiwan
6Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan
* presenting author:Chun-Hao Ma,
In the diligent pursuit of low-power consumption, multifunctional, and environmentally friendly electronics, more sophisticated requirements on functional materials are on demand. For example, flexible electronics represents a fast developing field and has a great potential to impact our daily life. In building up flexible electronics, the materials with controllable conduction, transparency, and good flexibility are required. Recently, the discovery of free-standing 2D materials has created a revolution to this field. Pioneered by graphene, these new 2D materials exhibit abundant unusual physical phenomena that is undiscovered in bulk forms. Van der Waals epitaxy, an epitaxial growth method to combine 2D and 3D materials, is one of current reliable manufacturing processes to fabricate 2D materials by growing these 2D materials epitaxially on 3D materials. In the mean time, van der Waals epitaxy has also been used to create free standing 3D materials by growing 3D materials on 2D materials and then removing them from 2D materials since the interfacial boding between 2D and 3D materials should be weak van der waals bonds. In this study, we intend to take the same concept, but to integrate a family of functional materials in order to open new avenue to flexible electronics. We use a 2D material, MICA, as the substrate due to its transparency and flexibility. And we take MoO2 as a model system to demonstrate a pathway to integrate 3D functional oxides on MICA. Van der waals epitaxy of MoO2 film is evidenced by a combination of RHEED, XRD, TEM. The properties of MoO2 is also characterized to ensure the intriguing functionalities. The flexible MoO2 on MICA and free-standing MoO2 thin film can be fabricated by this approach. Such a result demonstrates a platform to build up flexible electronics based on functional oxides.

Keywords: MoO2, Van der Waals Epitaxy, Metal Oxide, Plused Laser Deposition