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

Research output: Contribution to journalArticle

18 Citations (Scopus)

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
Article number1805082
JournalAdvanced Materials
Volume31
Issue number4
DOIs
Publication statusPublished - 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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    Chen, Y., Huang, W., Sangwan, V. K., Wang, B., Zeng, L., Wang, G., Huang, Y., Lu, Z., Bedzyk, M. J., Hersam, M. C., Marks, T. J., & Facchetti, A. (2019). Polymer Doping Enables a Two-Dimensional Electron Gas for High-Performance Homojunction Oxide Thin-Film Transistors. Advanced Materials, 31(4), [1805082]. https://doi.org/10.1002/adma.201805082