Room Temperature Negative Differential Resistance Induced by Artificial Sulfur Vacancy in MoS₂ Transistors

Wen-Hao Chang^1*, Chun-I Lu¹, Tilo H. Yang¹, Shu-Ting Yang¹, Kristan Bryan Simbulan^1,2, Chih-Pin Lin³, Tuo-Hung Hou³, Chia-Hao Chen^4,5, Kai-Shin Li⁶, Ting-Hua Lu¹, Yann-Wen Lan¹

¹Department of Physics, National Taiwan Normal University, Taipei, Taiwan
²Department of Mathematics and Physics, University of Santo Tomas, Manila, Philippines
³Department of Electronics Engineering & Institute of Electronics, National Yang Ming Chiao Tung University, Hsinchu, Taiwan
⁴National Synchrotron Radiation Research Center, Hsinchu, Taiwan
⁵Department of Electrophysics, National Yang Ming Chiao Tung University, Hsinchu, Taiwan
⁶Taiwan Semiconductor Research Institute, Hsinchu, Taiwan

* Presenter:Wen-Hao Chang, email:jp6cl6@gmail.com

The negative differential resistance (NDR) effect is widely investigated for electronics applications. In the recent decade, two-dimensional transition metal dichalcogenides (2D TMDs)-based transistors have exhibited NDR behavior in various heterostructures integrated by layered materials. However, theoretical calculation demonstrates that the monolayer MoS₂ is profoundly affected by sulfur (S) vacancy to observe the NDR effect. In this work, monolayer MoS₂ field-effect transistors (FETs) with a specific amount of S-vacancy are fabricated by using chemical and physical treatments. Based on systematical analysis of the photoluminescence (PL), Raman, and X-ray photoemission spectroscopy (XPS), the NDR can be clearly observed at room temperature in the monolayer MoS₂ FETs with S-vacancy (V_S ~ 5 %). Moreover, the NDR behavior can be effectively modulated by either gate electric field or light intensity. We believe that using such defect engineering technology to fabricate defective monolayer TMDs-based devices will spring out for more electronics applications in the future.

Keywords: MoS₂, negative differential resistance, defect, sulfur vacancy, X-ray photoemission spectroscopy