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Nanoscale Mapping of Photoconductivity Enhanced by Localized Charge Traps in the Grain Structures of MoS<sub>2</sub> Monolayer

ORAL

Abstract

We present a method for the nanoscale mapping of photoconductivity and charge trap density in the grain structures of a monolayer molybdenum disulfide (MoS2). In this method, the lateral current and noise maps were measured by scanning the MoS2 surface with a nanoscale conducting contact probe. The measured data were analyzed to obtain the sheet resistance and charge trap density maps in the MoS2 grain structures. Interestingly, the sheet resistance was found inversely proportional to the charge trap density in the grains. It was explained by the sulfur vacancies working as both charge hopping sites and traps in the MoS2 monolayer. When illuminated with a light, the regions with a relatively high trap density showed a high photoconductivity. These results indicate that high photoconductivity was enhanced by charge traps. This method can be a powerful tool for the basic research about noises and the device applications based on two-dimensional materials.

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Presenters

  • Hyesong Jeon

    Department of Materials Science and Engineering, Seoul National University, Seoul, 08826, Korea

Authors

  • Hyesong Jeon

    Department of Materials Science and Engineering, Seoul National University, Seoul, 08826, Korea

  • Myungjae Yang

    Department of Physics and Astronomy, Seoul National University, Seoul, 08826, Korea

  • Taeyoung Kim

    Department of Physics and Astronomy, Seoul National University, Seoul, 08826, Korea

  • Takhee Lee

    Department of Physics and Astronomy, Seoul National University, Seoul, 08826, Korea

  • Seunghun Hong

    Department of Physics and Astronomy, and Institute of Applied Physics, and Department of Biophysics and Chemical Biology, Seoul National University, Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University, Seoul, 08826, Korea