Emergence of Self-Recovery on PtTe2 Surfaces
Wan-Hsin Chen1*, Naoya Kawakami1, Jing-Wen Xue2, Lai-Hsiang Kuo2, Chia-Nung Kuo3, Chin-Shan Lue3, Meng-Fan Luo2, Chun-Liang Lin1
1Department of Electrophysics, National Chiao Tung University, Hsinchu, Taiwan
2Department of Physics, National Central University, Jhongli, Taiwan
3Department of Physics, National Cheng Kung University, Tainan, Taiwan
* Presenter:Wan-Hsin Chen, email:lucychen.ep05g@g2.nctu.edu.tw
Transition metal dichalcogenides (TMDs) with huge diversities share remarkable properties in many fields [1]. Thus, they exhibit an extremely high potential for next-generation devices from electronics to optics. However, TMD layers grown by chemical vapor deposition (CVD) usually exhibit a large number of defects. It is an urgent request to find a simple method to eliminate the defects after synthesis. PtTe2 is a typical TMD material crystallizing in 1T structure. The in situ cleaved CVD-growth PtTe2 reveals a clean surface with many intrinsic defects, which is observed by scanning tunneling microscopy (STM). Even though the PtTe2 crystal is annealed in an ultra-high vacuum (UHV) chamber, the surface still contains a lot of defect. Nevertheless, we found that the surface can be self-recovered by annealing after a short-time Ar+ sputtering. This recovery progress is also confirmed by X-ray photoelectron spectroscopy (XPS) and reflection high-energy electron diffraction (RHEED) measurement. Our study provides us a new method to manufacture defect-free TMD layers.

[1] C. L. Lin et al., J. Phys.: Condens. Matter 32 243001 (2020).

Keywords: Scanning Tunneling Microscopy (STM), Platina Ditelluride (PtTe2), Transition Metal Dichalcogenides (TMDs), Defect