Channel-Length-Modulated Avalanche Multiplication in Ambipolar WSe2Field-Effect Transistors

Jaeyoung Kim, Kyungjune Cho, Jinsu Pak, Woocheol Lee, Junseok Seo, Jae Keun Kim, Jiwon Shin, Juntae Jang, Kyeong Yoon Baek, Jonghoon Lee, Seungjun Chung, Keehoon Kang, Takhee Lee

Research output: Contribution to journalArticlepeer-review

4 Citations (Scopus)


Recently there has been growing interest in avalanche multiplication in two-dimensional (2D) materials and device applications such as avalanche photodetectors and transistors. Previous studies have mainly utilized unipolar semiconductors as the active material and focused on developing high-performance devices. However, fundamental analysis of the multiplication process, particularly in ambipolar materials, is required to establish high-performance electronic devices and emerging architectures. Although ambipolar 2D materials have the advantage of facile carrier-type tuning through electrostatic gating, simultaneously allowing both carrier types in a single channel poses an inherent difficulty in analyzing their individual contributions to avalanche multiplication. In ambipolar field-effect transistors (FETs), two phenomena of ambipolar transport and avalanche multiplication can occur, and both exhibit secondary rise of output current at high lateral voltage. We distinguished these two competing phenomena using the method of channel length modulation and successfully analyzed the properties of electron- and hole-initiated multiplication in ambipolar WSe2 FETs. Our study provides a simple and robust method to examine carrier multiplication in ambipolar materials and will foster the development of high-performance atomically thin electronic devices utilizing avalanche multiplication.

Original languageEnglish
Pages (from-to)5376-5383
Number of pages8
JournalACS Nano
Issue number4
Publication statusPublished - 2022 Apr 26

Bibliographical note

Funding Information:
The authors appreciate the financial support of the National Research Foundation of Korea (NRF) grant (No. 2021R1A2C3004783 and No. 2021R1C1C1010266) and the Nano•Material Technology Development Program grant (No. 2021M3H4A1A02049651) through the NRF funded by the Ministry of Science and ICT of Korea. S.C. appreciates the support of the NRF grant (No. NRF-2020R1A2C4001948) funded by the Ministry of Science and ICT of Korea.

Publisher Copyright:
© 2022 American Chemical Society.

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Engineering(all)
  • Physics and Astronomy(all)


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