Cyanoethyl cellulose-based nanocomposite dielectric for low-voltage, solution-processed organic field-effect transistors (OFETs)


Faraji S., Danesh E., Tate D. J., Turner M. L., Majewski L. A.

Journal of Physics D: Applied Physics, vol.49, no.18, 2016 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 49 Issue: 18
  • Publication Date: 2016
  • Doi Number: 10.1088/0022-3727/49/18/185102
  • Journal Name: Journal of Physics D: Applied Physics
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Keywords: high-k polymer nanocomposite, low voltage operation, organic-field-effect transistor (OFET), polymer semiconductor
  • Istanbul Technical University Affiliated: No

Abstract

Low voltage organic field-effect transistors (OFETs) using solution-processed cyanoethyl cellulose (CEC) and CEC-based nanocomposites as the gate dielectric are demonstrated. Barium strontium titanate (BST) nanoparticles are homogeneously dispersed in CEC to form the high-k (18.0 ± 0.2 at 1 kHz) nanocomposite insulator layer. The optimised p-channel DPPTTT OFETs with BST-CEC nanocomposite as the gate dielectric operate with minimal hysteresis, display field-effect mobilities in excess of 1 cm2 V-1 s-1 at 3 V, possess low subthreshold swings (132 ± 8 mV dec-1), and have on/off ratios greater than 103. Addition of a 40-50 nm layer of cross-linked poly(vinyl phenol) (PVP) on the surface of the nanocomposite layer significantly decreases the gate leakage current (<10-7 A cm-2 at ±3 V) and the threshold voltage (< -0.7 V) enabling operation of the OFETs at 1.5 V. The presented bilayer BST-CEC/PVP dielectrics are a promising alternative for the fabrication of low voltage, solution-processed OFETs that are suitable for use in low power, portable electronics.