Mechanical Stress Modulation of Resistance in MoS2 Junctions

• DOI: 10.1021/acs.nanolett.1c04019
• Publication Date: 2022-01-18T22:19:32Z
• Authors: Pradeep Chaudhary; Haidong Lu; Michael Loes; Alexey Lipatov; Alexander Sinitskii; Alexei Gruverman
• Keywords: 0301 basic medicine; 03 medical and health sciences

Strain engineering is a powerful strategy to control the physical properties of material-enabling devices with enhanced functionality and improved performance. Here, we investigate a modulation of the transport behavior of the two-dimensional MoS2 junctions under the mechanical stress induced by a tip of an atomic force microscope (AFM). We show that the junction resistance can be reversibly tuned by up to 4 orders of magnitude by altering a tip-induced force. Analysis of the stress-induced evolution of the I-V characteristics indicates a combined effect of the tip-induced strain and strain gradient on the energy barrier height and profile. In addition, we show that the tip-generated flexoelectric effect leads to significant enhancement of the photovoltaic effect in the MoS2 junctions. A combination of the optical and mechanical stimuli facilitates reversible photomechanical tuning of resistance of the narrow-band 2D semiconductors and development of devices with an enhanced photovoltaic response.