Polyelectrolyte based organic field effect transistors

Abstract: In this thesis work, the fabrication of dual gate organic field-effect transistors (DGOFETs) using polyanionic proton conductor named polyvinylphosphonic acid and acrylic acid P(VPA-AA), SiO 2 as gate insulating materials and poly(3-hexylthiophene) (P3HT) as organic semiconductor have been studied. Upon operation, the top insulating layer forms large electric double layer capacitors (EDLCs)at the Ti/P(VPA-AA) and P(VPAAA)/ P3HT interfaces. This new type of robust transistor, called as EDLC-OFET, displays fast response (<0.3 ms), a reasonably high field effect mobility (0.0030 cm² V -1 s-1), a low ION/IOFF ratio (150), and operates at low voltage (<1 V). Results concerning the influence of bottom gate on the DG-OFET are presented and discussed. The results presented are important for low-cost printed polymer electronics. Also, various conducting polymer gate electrode in addition to laminated OFET to form EDLC-OFET have been tested. Conducting polymers include PEDOT:PSS and polyaniline (PANI).