Investigation on dependency mechanism of inverter voltage gain on current level of photo stressed depletion mode thin-film transistors

Byeong Hyeon Lee, Sangsig Kim, Sang Yeol Lee

Research output: Contribution to journalArticle


The dependency of the inverter voltage gain on the current level (I Level ) of depletion mode (D-mode) thin-film transistors (TFTs) has been investigated with only n-type oxide semiconductor-based TFTs. It is clear that the voltage gain strongly depends on the D-mode I Level . To investigate the dependency, photo stress was applied to the D-mode TFT to compare the inverter characteristics depending on the D-mode I Level . As the photo stress time increased, the D-mode I Level increased, and the voltage gains were degraded as a result. This was mainly because the I Level of the D-mode is formed in the high section of the subthreshold slope (S.S) of the enhancement mode (E-mode) TFT when the photo stress was applied. By designing an inverter with a low D-mode I Level , a high voltage gain of 9.85 was obtained at V DD = 3 V. It is important to note that the S.S value of the E-mode and the I Level of the D-mode should be optimized for high voltage gain for the application of next generation integrated circuits and highly sensitive photodetectors.

Original languageEnglish
Pages (from-to)5-11
Number of pages7
JournalSolid-State Electronics
Publication statusPublished - 2019 Jun 1


ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Electrical and Electronic Engineering
  • Materials Chemistry

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