Solution-Processed Bilayer Dielectrics for Flexible Low-Voltage Organic Field-Effect Transistors in Pressure-Sensing Applications

Zhigang Yin, Ming Jie Yin, Ziyang Liu, Yangxi Zhang, A. Ping Zhang, Qingdong Zheng

Research output: Journal article publicationJournal articleAcademic researchpeer-review

68 Citations (Scopus)


Flexible pressure sensors based on organic field-effect transistors (OFETs) have emerged as promising candidates for electronic-skin applications. However, it remains a challenge to achieve low operating voltages of hysteresis-free flexible pressure sensors. Interface engineering of polymer dielectrics is a feasible strategy toward sensitive pressure sensors based on low-voltage OFETs. Here, a novel type of solution-processed bilayer dielectrics is developed by combining a thick polyelectrolyte layer of polyacrylic acid (PAA) with a thin poly(methyl methacrylate) (PMMA) layer. This bilayer dielectric can provide a vertical phase separation structure from hydrophilic interface to hydrophobic interface which adjoins well to organic semiconductors, leading to improved stability and remarkably reduced leakage currents. Consequently, OFETs using the PMMA/PAA dielectrics reveal greatly suppressed hysteresis and improved mobility compared to those with a pure PAA dielectric. Using the optimized PMMA/PAA dielectric, flexible OFET-based pressure sensors that show a record high sensitivity of 56.15 kPa−1 at a low operating voltage of −5 V, a fast response time of less than 20 ms, and good flexibility are further demonstrated. The salient features of high capacitance, good dielectric performance, and excellent reliability of the bilayer dielectrics promise a bright future of flexible sensors based on low-voltage OFETs for wearable electronic applications.

Original languageEnglish
Article number1701041
JournalAdvanced Science
Issue number9
Publication statusPublished - Sept 2018


  • dielectrics
  • flexible electronics
  • organic field-effect transistors
  • pressure sensitivity
  • pressure sensors

ASJC Scopus subject areas

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


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