Schottky barrier height engineering on MoS2 field-effect transistors using a polymer surface modifier on a contact electrode

Dongwon Choi, Jeehoon Jeon, Tae Eon Park, Byeong Kwon Ju, Ki Young Lee

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)


Two-dimensional (2D) materials are highly sought after for their superior semiconducting properties, making them promising candidates for next-generation electronic and optoelectronic devices. Transition-metal dichalcogenides (TMDCs), such as molybdenum disulfide (MoS2) and tungsten diselenide (WSe2), are promising alternative 2D materials. However, the devices based on these materials experience performance deterioration due to the formation of a Schottky barrier between metal contacts and semiconducting TMDCs. Here, we performed experiments to reduce the Schottky barrier height of MoS2 field-effect transistors (FETs) by lowering the work function (Ф m = E vacuum − E F,metal) of the contact metal. We chose polyethylenimine (PEI), a polymer containing simple aliphatic amine groups (–NH2), as a surface modifier of the Au (Ф Au = 5.10 eV) contact metal. PEI is a well-known surface modifier that lowers the work function of various conductors such as metals and conducting polymers. Such surface modifiers have thus far been utilized in organic-based devices, including organic light-emitting diodes, organic solar cells, and organic thin-film transistors. In this study, we used the simple PEI coating to tune the work function of the contact electrodes of MoS2 FETs. The proposed method is rapid, easy to implement under ambient conditions, and effectively reduces the Schottky barrier height. We expect this simple and effective method to be widely used in large-area electronics and optoelectronics due to its numerous advantages.

Original languageEnglish
Article number80
JournalDiscover Nano
Issue number1
Publication statusPublished - 2023 Dec

Bibliographical note

Funding Information:
This work was supported by the National Research and Development Program through the National Research Foundation of Korea (NRF) (No. NRF-2020M3F3A2A01081635) and the KIST Institutional Program (2E32251).

Publisher Copyright:
© 2023, The Author(s).


  • MoS FET
  • Photoelectric effect
  • Polyethylenimine
  • Schottky barrier height
  • Thermionic emission

ASJC Scopus subject areas

  • General Materials Science
  • Condensed Matter Physics


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