Emergence of Self-Recovery on PtTe2 Surfaces

Wan-Hsin Chen^1*, 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.

References:
[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