Analysis of Ultrahigh Apparent Mobility in Oxide Field-Effect Transistors

Changdong Chen, Bo Ru Yang, Gongtan Li, Hang Zhou, Bolong Huang, Qian Wu, Runze Zhan, Yong Young Noh, Takeo Minari, Shengdong Zhang, Shaozhi Deng, Henning Sirringhaus, Chuan Liu

Research output: Journal article publicationJournal articleAcademic researchpeer-review

21 Citations (Scopus)


For newly developed semiconductors, obtaining high-performance transistors and identifying carrier mobility have been hot and important issues. Here, large-area fabrications and thorough analysis of InGaZnO transistors with enhanced current by simple encapsulations are reported. The enhancement in the drain current and on–off ratio is remarkable in the long-channel devices (e.g., 40 times in 200 µm long transistors) but becomes much less pronounced in short-channel devices (e.g., 2 times in 5 µm long transistors), which limits its application to the display industry. Combining gated four-probe measurements, scanning Kelvin-probe microscopy, secondary ion mass spectrometry, X-ray photoelectron spectroscopy, and device simulations, it is revealed that the enhanced apparent mobility up to several tens of times is attributed to the stabilized hydrogens in the middle area forming a degenerated channel area while that near the source-drain contacts are merely doped, which causes artifact in mobility extraction. The studies demonstrate the use of hydrogens to remarkably enhance performance of oxide transistors by inducing a new mode of device operation. Also, this study shows clearly that a thorough analysis is necessary to understand the origin of very high apparent mobilities in thin-film transistors or field-effect transistors with advanced semiconductors.

Original languageEnglish
Article number1801189
JournalAdvanced Science
Issue number7
Publication statusPublished - 3 Apr 2019


  • carrier mobility
  • doping
  • four-probe measurement
  • surface potential scanning
  • thin-film transistors

ASJC Scopus subject areas

  • Medicine (miscellaneous)
  • Chemical Engineering(all)
  • Materials Science(all)
  • Biochemistry, Genetics and Molecular Biology (miscellaneous)
  • Engineering(all)
  • Physics and Astronomy(all)

Cite this