Light-Induced Surface Potential Modification in MoS2 Monolayers on Au Nanostripe Arrays

Abstract

Abstract In this work, the surface potential ( V S ) of exfoliated MoS 2 monolayers on Au nanostripe arrays with period of 500 nm was investigated using Kelvin probe force microscopy. The surface morphology showed that the suspended MoS 2 region between neighboring Au stripes underwent tensile-strain. In the dark, the V S of the MoS 2 region on the Au stripe ( V S -Au) was larger than that of the suspended MoS 2 region ( V S -S). However, under green light illumination, V S -Au became smaller than V S -S. To explain the V S modification, band diagrams have been constructed taking into consideration not only the local strain but also the electronic interaction at the MoS 2 /Au interface. The results of this work provide a basis for understanding the electrical properties of MoS 2 -metal contacts and improving the performance of MoS 2 -based optoelectronic devices.