Negative Differential Resistance in Tungsten Disulfide Quantum Dots

Yu-Ting Chen^1*, Ji-Lin Shen¹

¹Department of Physic, Chung Yuan Christian University, Taoyuan, Taiwan

* Presenter:Yu-Ting Chen, email:10412239@cycu.org.tw

Negative differential resistance (NDR) plays an important role in electronic components such as switches, memory devices, and analog-to-digital converters. Such a wide range of applications has incited profound interest in the study of NDR. Controlling the NDR property is one of important issues to implement the applications in devices. In this paper, disulfide (WS2) quantum dots (QDs) were utilized for NDR study. We used the current-voltage (I-V) measurements to show that WS2 QDs exhibit obvious NDR phenomena under external bias voltages. A peak-to-valley ratio of NDR with 10.1 has been reached for WS2 QDs under the applied voltage from -4 to 4 V. The NDR peak and peak-to-valley ratio of NDR can be adjusted by controlling the voltage sweep rate and air pressure. Further, the introduction of hydrogen peroxide demonstrated pronounced effects on existence of NDR. When the concentration of hydrogen peroxide increases or the voltage sweep rate increases, the peak-to-valley ratio of the NDR increases. This research suggests that the WS2 QD could be used as an important nanomaterial for development of the NDR-based devices.

Keywords: 2D materials, Tungsten disulfide, Quantum dot, Negative Differential Resistance