Polymer Doping Enables a Two-Dimensional Electron Gas for High-Performance Homojunction Oxide Thin-Film Transistors

Yao Chen, Wei Huang, Vinod K. Sangwan, Binghao Wang, Li Zeng, Gang Wang, Yan Huang, Zhiyun Lu, Michael J. Bedzyk, Mark C. Hersam*, Tobin J. Marks, Antonio Facchetti

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

22 Scopus citations

Abstract

High-performance solution-processed metal oxide (MO) thin-film transistors (TFTs) are realized by fabricating a homojunction of indium oxide (In2O3) and polyethylenimine (PEI)-doped In2O3 (In2O3:x% PEI, x = 0.5–4.0 wt%) as the channel layer. A two-dimensional electron gas (2DEG) is thereby achieved by creating a band offset between the In2O3 and PEI-In2O3 via work function tuning of the In2O3:x% PEI, from 4.00 to 3.62 eV as the PEI content is increased from 0.0 (pristine In2O3) to 4.0 wt%, respectively. The resulting devices achieve electron mobilities greater than 10 cm2 V−1 s−1 on a 300 nm SiO2 gate dielectric. Importantly, these metrics exceed those of the devices composed of the pristine In2O3 materials, which achieve a maximum mobility of ≈4 cm2 V−1 s−1. Furthermore, a mobility as high as 30 cm2 V−1 s−1 is achieved on a high-k ZrO2 dielectric in the homojunction devices. This is the first demonstration of 2DEG-based homojunction oxide TFTs via band offset achieved by simple polymer doping of the same MO material.

Original languageEnglish (US)
Article number1805082
JournalAdvanced Materials
Volume31
Issue number4
DOIs
StatePublished - Jan 25 2019

Keywords

  • 2D electron gases
  • PEI-doped InO
  • homojunctions
  • oxide electronics

ASJC Scopus subject areas

  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering

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