Photoconductivity Enhancement in Atomically Thin Molybdenum Disulfide through Local Doping from Confined Water

Two-dimensional transition metal dichalcogenide (TMDC) materials have shown great potential for usage in opto-electronic devices, especially down to the regime of a few layers to a single layer. However, at these limits, the material properties can be strongly influenced by the interfaces. By using photoconductive atomic force microscopy, we show a local enhancement of photoconductivity at the nanoscale in bilayer molybdenum disulfide on mica, where water is confined between the TMDC and the substrate. We have found that the structural phase of the water influences the doping level and thus the tunneling barrier at the nanojunction. This leads to an increase in photocurrent and enhanced photopower generation.

Automated summary

By using photoconductive atomic force microscopy, we have observed a local enhancement of photoconductivity on a bilayer molybdenum disulfide on mica system, where water is present between the TMDC and the substrate. The structural phase of the water influences the doping level and thus the tunneling barrier at the nanojunction, leading to an increase in photocurrent and enhanced photopower generation.