Mechanisms of negative differential resistance in glutamine-functionalized WS2quantum dots

Denice N Feria; Sonia Sharma; Yu-Ting Chen; Zhi-Ying Weng; Kuo-Pin Chiu; Jy-Shan Hsu; Ching-Ling Hsu; Chi-Tsu Yuan; Tai-Yuan Lin; Ji-Lin Shen

doi:10.1088/1361-6528/ac3685

Mechanisms of negative differential resistance in glutamine-functionalized WS₂quantum dots

Nanotechnology. 2021 Nov 24;33(7). doi: 10.1088/1361-6528/ac3685.

Authors

Affiliations

¹ Department of Optoelectronics and Materials Technology, National Taiwan Ocean University, Keelung, 202, Taiwan.
² Department of Physics and Center for Nanotechnology, Chung Yuan Christian University, Chung-Li, 320314, Taiwan.

PMID: 34736241
DOI: 10.1088/1361-6528/ac3685

Abstract

Understanding the mechanism of the negative differential resistance (NDR) in transition metal dichalcogenides is essential for fundamental science and the development of electronic devices. Here, the NDR of the current-voltage characteristics was observed based on the glutamine-functionalized WS₂quantum dots (QDs). The NDR effect can be adjusted by varying the applied voltage range, air pressure, surrounding gases, and relative humidity. A peak-to-valley current ratio as high as 6.3 has been achieved at room temperature. Carrier trapping induced by water molecules was suggested to be responsible for the mechanism of the NDR in the glutamine-functionalized WS₂QDs. Investigating the NDR of WS₂QDs may promote the development of memory applications and emerging devices.

Keywords: WS2 QDs; amino functionalization; carrier injection; negative differential resistance (NDR); trapped states.